Advances in Oral Exfoliative Cytology: From Cancer Diagnosis to Systemic Disease Detection.

Oral exfoliative cytology has emerged as a valuable tool in the early detection of oral cancer and other systemic diseases. This review comprehensively examines the current applications and recent advancements in oral exfoliative cytology techniques. We analyzed published literature from the past decade, focusing on methodological improvements, diagnostic accuracy, and emerging applications. Key findings include: (1) Enhanced cell collection and preparation methods have significantly improved sample quality and diagnostic reliability. (2) Integration of molecular markers and DNA analysis with traditional cytomorphological assessment has increased diagnostic sensitivity and specificity for oral cancer detection. (3) Novel applications in systemic disease detection, including diabetes and iron overload disorders, demonstrate the expanding utility of this technique. (4) Computer-assisted analysis and deep learning algorithms show promise in improving diagnostic accuracy and efficiency. Despite these advancements, challenges remain in standardization and widespread clinical implementation. This review provides a critical evaluation of oral exfoliative cytology's current status and future potential in oral and systemic disease diagnosis.

Diagnostic Performance of Thyroid FNA: Experience of Belarusian National Referral Thyroid Cancer Center.

BACKGROUND: A fine-needle aspiration (FNA) biopsy is a basic procedure to verify the morphology of thyroid nodules. However, significant variations in the diagnostic performance of FNA, as well as fluctuations in the rate of malignancy (ROM) in different categories of the Bethesda System for Reporting Thyroid Cytopathology, have been discovered in many studies. The development and employment of additional molecular tests in daily clinical practice require an understanding of the prevalence and structure of thyroid malignancy in each category of the Bethesda system. METHODS: Current research is a continuous retrospective cohort study of the results of the examination and treatment of 1652 patients with thyroid tumors who have undergone primary surgery in 2021 at a national referral thyroid cancer center. FNA diagnostic performance was studied by comparing cytological diagnoses with histological outcomes. The authors evaluated ROM in each Bethesda category and identified the tumors representing a diagnostic pitfall. RESULTS: The overall ROM was 72.4%. When considering ROM in each Bethesda category, it was 16.7% in Bethesda I, 10.1% in Bethesda II, 23.0% in Bethesda IV, 74.8% in Bethesda V, 99.4% in Bethesda VI. The false-positive rate was 65.0%, false negative-0.67%. Follicular and oncocytic adenomas, as well as the follicular variant of papillary thyroid cancer, were the most troublesome entities for patients' management. CONCLUSION: ROM was comparable to the values implied by the Bethesda system. Follicular tumors were the main source of high false-positive rates. This necessitates the refinement of existing tests and the development of new diagnostic tests to overcome the abovementioned problems.

Endoscopic ultrasound (EUS) elastography-guided fine-needle aspiration cytology (FNAC) versus conventional EUS FNAC for solid pancreatic lesions: A pilot randomized trial.

BACKGROUND: Endoscopic ultrasound guided fine-needle aspiration (EUS FNA) is the first-line modality to diagnose suspected solid pancreatic malignant lesions. Elastography-guided FNA has been shown to improve the diagnostic yield of EUS FNA but prospective studies are limited. The aim of the study was to compare diagnostic accuracy, sensitivity and specificity of conventional and elastography-guided EUS FNA in patients with suspected malignant pancreatic solid masses. METHODS: Patients with suspected malignant solid pancreatic lesions presenting to our institute from July 2021 to January 2023 were recruited and randomized to conventional and elastography-guided EUS FNA using a 22-G EUS FNA needle. Diagnostic accuracy, sensitivity, specificity and positive and negative predictive values were calculated. RESULTS: Total 48 patients were initially screened for inclusion in the study, of which six were excluded and 42 patients underwent randomization. Finally, 20 patients in each group underwent the assigned intervention and were analyzed further. Baseline patient characteristics were similar in conventional FNA and elastography-guided FNA group with median age 52 (range 29-74) years and 51.8 (range 31-72) years, respectively, males being 70% and 75%, respectively. Median size of the lesion was 34 mm (range 14-48 mm) and 37 (range 18 to 50 mm), respectively, for both conventional and elastography arm. The average size of the lesion was 35.7 mm. Overall, the diagnosis of adenocarcinoma was made in 65% of cases. In the remaining cases, diagnoses were inflammatory mass, Castleman's disease, solid pseudopapillary epithelial neoplasm (SPEN), diffuse large B-cell lymphoma (DLBCL), pancreatic gastrointestinal stromal tumor (GIST) and metastasis. Conventional EUS FNA had diagnostic accuracy, sensitivity, specificity and positive and negative predictive values of 90%, 87.5%, 100%, 100% and 62.92%, respectively, and elastography-guided EUS FNA had diagnostic accuracy, sensitivity, specificity and positive and negative predictive values of 85%, 100%, 100% and 54.59%, respectively. No severe adverse events were noted. CONCLUSION: There is no significant difference between conventional and elastography-guided EUS FNA in terms of diagnostic accuracy, sensitivity, specificity and positive and negative predictive values. Both techniques appear safe and effective for characterizing solid pancreatic masses and elastography did not score numerically over the conventional arm.

Artificial intelligence interpretation of touch print smear cytology of testicular specimen from patients with azoospermia.

PURPOSE: Identification of mature sperm at microdissection testicular sperm extraction (mTESE) is a crucial step of sperm retrieval to help patients with non-obstructive azoospermia (NOA) proceed to intracytoplasmic sperm injection. Touch print smear (TPS) cytology allows immediate interpretation and prompt sperm identification intraoperatively. In this study, we leverage machine learning (ML) to facilitate TPS reading and conquer the learning curve for new operators. MATERIALS AND METHODS: One hundred seventy-six microscopic TPS images from the testicular specimen of patients with azoospermia at Taipei Veterans General Hospital were retrospectively collected, including categories of Sertoli cell, primary spermatocytes, round spermatids, elongated spermatids, immature sperm, and mature sperm. Among them, 118 images were assigned as the training set and 29 images as the validation set. RetinaNet (Lin et al. in IEEE Trans Pattern Anal Mach Intell. 42:318-327, 2020), a one-stage detection framework, was adopted for cell detection. The performance was evaluated at the cell level with average precision (AP) and recall, and the precision-recall (PR) curve was displayed among an independent testing set that contains 29 images that aim to assess the model. RESULTS: The training set consisted of 4772 annotated cells, including 1782 Sertoli cells, 314 primary spermatocytes, 443 round spermatids, 279 elongated spermatids, 504 immature sperm, and 1450 mature sperm. This study demonstrated the performance of each category and the overall AP and recall on the validation set, which were 80.47% and 96.69%. The overall AP and recall were 79.48% and 93.63% on the testing set, while increased to 85.29% and 93.80% once the post-meiotic cells were merged into one category. CONCLUSIONS: This study proposed an innovative approach that leveraged ML methods to facilitate the diagnosis of spermatogenesis at mTESE for patients with NOA. With the assistance of ML techniques, surgeons could determine the stages of spermatogenesis and provide timely histopathological diagnosis for infertile males.

Optimization of HPV-positive women triage with p16/Ki67 dual staining cytology in an organized cervical cancer screening program in the center region of Portugal.

BACKGROUND: Organized cervical cancer (CxCa) screening is the most effective secondary prevention method to decrease the disease incidence and mortality. Screening for infection with 14 high-risk HPV genotypes (hrHPV) is recommended as primary screening test. Since only ca. 6 % of HPV-positive (HPV+) women will develop a high-grade lesion in 5 years, triage is critical for risk stratification and management of colposcopy resources. Dual staining (DS) p16/Ki67 cytology is an alternative to Papanicolau cytology (PAP) for triage of HPV+women, with potential improvements in sensitivity and specificity, and optimization of colposcopy referrals. OBJECTIVES: To compare PAP vs DS cytology in terms of (i) optimization of referrals for colposcopy and (ii) risk stratification to better define the follow-up interval. STUDY DESIGN: Retrospective analysis of the CxCa screening database of Centro Hospitalar Universitário de Coimbra (CHUC), one of the centralized diagnostic laboratories for the CxCa screening program of the central region of Portugal, between July 2019 and May 2023. At CHUC, since July 2019, all samples from hrHPV+women have been triaged with liquid PAP and tested with DS cytology. RESULTS: At baseline (1032 HPV+women), 1028 women were tested with DS: 739 women were DS negative (DS-) [70.7 % with normal PAP cytology (NILM) and 29.3 % with abnormal PAP cytology (ASC-US+)], and 289 were DS positive (DS+) (1.1 % NILM and 98.6 % ASC-US+). DS positivity as referral criterion for colposcopy instead of ASC-US+would have reduced the number of colposcopies by 39.4 % overall and by 48.3 % for other 12 hrHPV, while improving the number of colposcopies per HSIL (3.9 vs. 2.4 overall and 4.9 vs. 2.9 for other 12 hrHPV). In this cohort, if the follow-up interval for women positive for other 12 hrHPV+and DS- would have been extended from 1 to 3 years, 799 follow-up consultations, 799 HPV re-tests, and 277 colposcopies (-64.7 %) would have been avoided, with an overall risk of missed HSIL lesions of 2.2 %. CONCLUSIONS: Triage with DS allows the optimization of colposcopy referrals and a safe extension of the follow-up interval to 3 years for other 12 hrHPV+/DS- women, eliminating the need for annual re-testing for many women.

Striated duct adenoma: The cytological description of a rare entity.

INTRODUCTION: Striated duct adenoma is a benign salivary gland tumour recently recognized by the World Health Organization. To date, no report has described the cytological features of this entity. MATERIALS AND METHODS: We report the case of a 60-year-old woman with a tumour in the right parotid gland with a diameter greater than 2.4 cm confirmed by imaging tests. RESULTS: Two fine-needle aspiration cytologies (FNAC) were performed with inconclusive results, reporting epithelioid and spindle-shaped cellularity, with little stroma, and nuclei with abundant pseudoinclusions. Myoepithelioma and Schwannoma were proposed as differential diagnoses. An immunocytochemical panel was performed, showing positivity for S-100, SOX10, CK7 and vimentin, and negativity for both myoepithelial (p63 and calponin) and thyroid markers. In the absence of a conclusive diagnosis, the patient accepted surgery. The biopsy results confirmed diagnosis of striated duct adenoma, with immunohistochemical features superimposable to cytology. CONCLUSION: Little information is available in the literature, both on biopsy and, more strikingly, on cytology of this neoplasm. The aim of this work is to provide cytological characteristics that allow diagnosis of this entity with FNAC and thus avoid unnecessary surgeries.

Peritoneal lavage cytology in patients with curative resection for stage II and III colorectal cancer: A multi-institutional prospective study.

Aim: To clarify the usefulness of intraoperative lavage cytology in patients undergoing curative resection for pStage II-III colorectal cancer in a prospective multicenter study. Methods: Patients preoperatively diagnosed with stage II-III colorectal cancer between 2013 and 2017 from 20 hospitals were enrolled. Lavage cytology was performed twice during the surgery. The primary endpoint was the effect of lavage cytology on the 5-year relapse-free survival (RFS) in patients with pStage II-III colorectal cancer. The secondary endpoint was the effect of lavage cytology on the 5-year overall survival (OS) and peritoneal recurrence. Results: A total of 1378 patients were eligible for analysis. The number of patients with pStage II-III colorectal cancer was 670 and 708, respectively. Fifty-four patients (3.9%) had positive cytological results. In pStage II patients, the 5-year RFS rates with positive and negative cytology were 61.1% and 81.6%, respectively (p = 0.023). The 5-year OS rates were 67.1% and 91.7%, respectively (p = 0.0083). However, there was no difference in RFS or OS between pStage III patients with positive and negative cytology results. The peritoneal recurrence rates were 11.8% and 1.5% in pStage II patients with positive and negative cytology results, respectively (p = 0.032). These rates were 10.5% and 2.5% in patients with stage III disease, respectively (p = 0.022). Conclusion: Stage II colorectal cancer patients with negative cytology had better outcomes than those with positive cytology. Peritoneal lavage cytology is useful for predicting peritoneal recurrence after curative resection of stage II-III colorectal cancer.

Cervical cytology in endometrial cancer patients with Lynch syndrome: opportunities for early detection and limitations.

INTRODUCTION: Timely detection of endometrial carcinoma in Lynch syndrome patients ensures prompt treatment and appropriate cancer screening for the patient and impacted family members. While cervical cytology is utilized primarily in cervical cancer screening, endometrial glandular abnormalities can be identified as part of routine cervical cancer screening or during work-up for abnormal uterine bleeding. MATERIALS AND METHODS: We retrospectively evaluated cervical cytology samples from Lynch syndrome patients with endometrial carcinoma to determine how often atypical/malignant glandular cells were identified on prior/concurrent cytology. RESULTS: We identified 14 Lynch syndrome patients with cervical cytology available within a year of endometrial carcinoma diagnosis. The average patient age was 55 years (36-73). Cervical cytology preceded diagnostic biopsy in 57% and was concurrent in 43%. A glandular abnormality was identified on original diagnosis in 43% and ranged from atypical glandular cells (AGC), not otherwise specified to adenocarcinoma consistent with endometrial primary. In 4 cases, abnormal cervical cytology triggered the subsequent biopsy. Evaluation of 8 cases with accessible cytology slides revealed 2 previously unrecognized glandular abnormalities, leading to an abnormal rate of 63% among cases reviewed retrospectively and a final glandular abnormality detection rate of 57% based on either original or review diagnosis. CONCLUSIONS: In summary, abnormal glandular cells were commonly identified in endometrial cancer patients with Lynch syndrome and led to endometrial cancer work-up and diagnosis in a subset. These results suggest that cervical cytology may have utility in endometrial cancer screening in this population and indicate that awareness of the patient's familial cancer risk is important for maximizing sensitivity of this test. They also caution against primary human papillomavirus screening in the Lynch syndrome population, as this may result in missed opportunities for early endometrial carcinoma detection among these high-risk individuals.

Pulmonary fibrosis and lung cancer: an analysis of the Clinical Practice Research Datalink linked to the National Cancer Registration Dataset.

We quantified the proportion of diagnoses of pulmonary fibrosis (PF) among 25 136 people with lung cancer and 250 583 matched controls and compared the natural history of lung cancer in people with and without PF. Diagnoses of PF were more common in people with lung cancer than those without (1.5% vs 0.8%, OR 1.97; 95% CI 1.77 to 2.21). Within people with PF, squamous cell carcinoma was more (22.9% vs 19.1%), and adenocarcinoma was less common (18.0% vs 21.3%). People with PF were less likely to have stage 4 disease at diagnosis (OR 0.43, 95% CI 0.28 to 0.65) but their survival was worse.

Successful Surveillance Using Endometrial Cytology in a Woman With Lynch Syndrome.

Lynch syndrome (LS) results from pathogenic variants in mismatch repair genes and is the most common hereditary cancer syndrome. Some guidelines or studies recommend restricting screening according to endometrial cancer (EC) using endometrial biopsy. The pooled sensitivity and specificity of endometrial cytology for detecting endometrial atypical hyperplasia or cancer have been reported to be as high as the pooled sensitivity and specificity of endometrial biopsy. We conduct transvaginal ultrasound and endometrial cytology in women with LS every six months as surveillance for gynecological malignancy. Through this surveillance program, we can detect early-stage EC in women with LS. Here, we report the case of a patient with stage IA EC detected by endometrial cytology and treated completely. The patient was a 47-year-old woman under surveillance for gynecological malignancy. She was diagnosed as having LS with a germline pathogenic variant in MSH6 after surgery for rectal cancer. Thereafter, gynecological surveillance was started. She had regular menstruation and never experienced atypical genital bleeding. However, her cytopathological findings indicated grade 1 endometrial carcinoma. Endometrial biopsy was performed and endometrial carcinoma was confirmed pathologically. A laparoscopic modified radical hysterectomy with bilateral salpingo-oophorectomy was performed. The resected specimen was reviewed pathologically, and the tumor was finally diagnosed as grade 1 endometrioid carcinoma confined to the endometrium without lymphovascular space invasion. She has remained asymptomatic and free of cancer for five years without any adjuvant therapy. We achieved successful surveillance using endometrial cytology. Endometrial cytology could replace endometrial biopsy as a screening tool for EC.

Comparative Evaluation of Honey Versus Alcohol as a Fixative in Cytological Samples: An Institutional Study.

Introduction: Fixation plays an important role in fixing the cells, making them amenable for evaluation. Ethanol (95%) has been used as a standard cytological fixative. Honey can be introduced as a natural fixative. Objectives: 1. To study cytomorphological features of smears fixed in 20% unprocessed honey. 2. To study the efficacy of honey as a fixative when compared with ethanol in both hematoxylin and eosin (H and E) stain and Papanicolaou (PAP) stain for cytological samples. Materials and Methods: A cross-sectional study was done in the Department of Pathology for 2 months on 100 cytological samples consisting of body fluids (peritoneal and pleural), cervical smears, and FNACs. These smears were fixed separately in 95% ethanol and 20% unprocessed honey for 5 minutes and were stained with both PAP and H and E stain. The cytomorphologies of both the smears were compared based on five parameters, clarity of staining, uniformity of staining, overall morphology, nuclear details, and cytoplasmic details, and the final score was calculated by adding all the scores: Total Score ≤2, poor score; 3-4, good score; 5, excellent score. Results: Cervical smears fixed in honey showed similar features to ethanol-fixed smears. Fluid smears fixed in honey and stained with PAP yielded superior results compared to those stained with H and E, as shown by a kappa value of 0.259. However, neither of the smears demonstrated statistical significance. The FNAC samples stained with H and E and PAP exhibited nearly identical results, with a kappa value of 0.688 and 0.647, respectively. FNAC and PAP smears were the next two most successful cytological smear types, with cervical smears exhibiting the best results of the three. Conclusion: In honey-fixed smears, we can easily observe all cellular features with clarity. It enhances safety and the working environment in the laboratory. Honey can serve as an effective substitute in situations where resources are limited.

Cytomorphological Features as a Subtyping Tool of Non-Small-Cell Lung Cancer in Brushing Bronchoscopic Samples.

Background and Objective: Nowadays, the separation of adenocarcinomas (ADCs) and squamous cell carcinomas (SCCs) is crucial given that there are new specific targeted therapies. So, the aim of this study was to examine the differences in cytomorphological features between ADC and SCC in bronchoscopic brush samples. Material and Methods: The retrospective study was conducted over a 3-year period at Western Balkan University Hospital. All brushing samples were analysed. According to the histopathological report, patients were classified into ADC and SCC groups. The cytomorphological features analysed in 95 samples were presence of necrosis, cell distribution, nuclear atypia, size of nuclei, and visibility of nucleoli. Statistical analysis was performed in JASP, and P values <0.05 were considered significant. Results: The necrotic background was more frequent in SCC samples. Small clusters sized ≤200 µm were found in 17.95% of samples from the SCC group and 53.57% in the ADC group. Large clusters sized >400 µm were found in 43.59% in the SCC group, while in the ADC group, it was found in 5.36%. There were no differences in nuclear atypia between groups. Nuclei that were >5x lymphocyte size were found more often in samples from ADC than in the SCC group (37.50 vs 10.25%). In 89.75% of samples from the SCC group, nuclei were ≤5x lymphocyte sizes, while in the ADC group, the percentage was 63.5%. Nucleoli were more often visible in samples from the ADC group compared to the SCC group (92.86% vs 64.10%, P < 0,05). Conclusions: Small clusters, large nuclei, and visible nucleoli were more frequent in the ADC group (P < 0.05), while large clusters, small nuclei, and invisible nucleoli were more frequent in the SCC group (P < 0.05).

Methodological and TNM Focus-Based Comparison of EGFR Mutation Status in Non-Small-Cell Lung Carcinomas.

Background: Epidermal growth factor receptor (EGFR) mutations in non-small-cell lung carcinomas (NSCLC) are a frequent class of driver mutations, and tyrosine kinase inhibitor (TKI) therapy provides considerable clinical benefits. Using the most effective and also easiest method for EGFR analysis is cost-effective and time-saving. In this study, we aimed to determine which method could be more effective by comparing the incidences of EGFR mutations in cytological and histological samples which were obtained by different methods also, whether there was a difference in the incidences of EGFR mutations between the primary foci, mediastinal lymph nodes, and distant metastatic foci. Materials and Methods: We retrospectively reviewed 420 cases of cytological materials, small biopsies, and surgical samples reported as NSCLC underwent EGFR analysis in our department between 2016 and 2022. We collected the data and interpreted the results from two different perspectives. Results: We identified 36 EGFR mutations in 362 biopsies (9.94%) and 17 in 58 cytology samples (29.31%). There is a significant difference between the two methods (P = 0.01*). We observed 38 EGFR mutations in 320 primary foci (11.87%), 7 EGFR mutations in 36 mediastinal or subcarinal lymph nodes (19.44%), and 8 EGFR mutations in 64 distant metastatic foci (12.50%). A significant difference was also observed in pleural samples (P = 0.005*). Conclusion: We observed more successful results with cell blocks obtained from liquid-based cytological specimens than with formalin-fixed, paraffin-embedded tissues obtained from resection or otherwise in our clinical routine. Our study results highlight the benefits of cytological specimens in molecular treatments and current therapy modalities.

Utility of Image Morphometry in the Atypical Urothelial Cells and High-Grade Urothelial Carcinoma Categories of the Paris System for Reporting Urinary Cytology.

Introduction: Urinary cytology (UrCy) is highly sensitive to diagnosing high-grade urothelial carcinoma (HGUC) but cannot predict muscularis propria invasion. Further, the atypical urothelial cell category (AUC) may have variable outcomes. Image morphometry (IM) may be a valuable adjunct technique in this setting. Hence, we evaluated IM in the AUC and HGUC categories to improve the diagnostic performance. Materials and Methods: The following six nuclear parameters were evaluated by IM on 3150 cells: nucleo-cytoplasmic (N:C) ratio, nuclear area, diameter, perimeter, standard deviation of the nuclear area (SDNA; pleomorphism) and integrated density (ID; nuclear chromasia), using the ImageJ software, in three cohorts based on the histopathology outcome: 20 cases of AUC - benign non-neoplastic outcome (AUC-B); 22 cases of HGUC Muscle invasive (HGUC-MI) and 21 cases of HGUC non-muscle invasive (HGUC-MF). Results: A retrospective analysis of urine cytology. The patient's ages ranged from 36 to 85 years, with a mean age of 60.6. The male-to-female ratio was 5.4:1. A total of 20 cases of AUC-B and 43 cases of HGUC were selected for IM analysis. HGUC cases had higher nuclear parameters than AUC-B, and HGUC-MI had higher SDNA, ID, diameter, and area than HGUC-MF. SDNA and ID predict muscularis propria invasion in HGUC. Conclusions: Image morphometry successfully differentiates HGUC cases from benign non-neoplastic ones and might help to identify muscularis propria invasion in HGUC using a combination of nuclear parameters.

Rhabdomyosarcoma of the skull with EWSR1 fusion and ALK and cytokeratin expression: a case report.

Rhabdomyosarcoma (RMS) comprises of heterogeneous group of neoplasms that occasionally express epithelial markers on immunohistochemistry (IHC). We herein report the case of a patient who developed RMS of the skull with EWSR1 fusion and anaplastic lymphoma kinase (ALK) and cytokeratin expression as cytomorphologic features. A 40-year-old man presented with a mass in his forehead. Surgical resection was performed, during which intraoperative frozen specimens were obtained. Squash cytology showed scattered or clustered spindle and epithelioid cells. IHC revealed that the resected tumor cells were positive for desmin, MyoD1, cytokeratin AE1/ AE3, and ALK. Although EWSR1 rearrangement was identified on fluorescence in situ hybridization, ALK, and TFCP2 rearrangement were not noted. Despite providing adjuvant chemoradiation therapy, the patient died of tumor progression 10 months after diagnosis. We emphasize that a subset of RMS can express cytokeratin and show characteristic histomorphology, implying the need for specific molecular examination.

Use of Diagnostic Laparoscopy and Peritoneal Washings for Pancreatic Cancer.

Pancreatic adenocarcinoma is an aggressive malignancy that often presents with advanced disease. Accurate staging is essential for treatment planning and shared decision-making with patients. Staging laparoscopy is a minimally invasive procedure that can detect radiographically occult metastatic disease. Its routine use with the collection of peritoneal washings in patients with pancreatic cancer remains controversial. We, herein, review the current literature concerning staging laparoscopy and peritoneal washings in patients with pancreatic cancer.

Solitary Cutaneous Mastocytoma in an Adult Diagnosed on Cytology: A Rare Case Report.

Mastocytosis is characterized by the proliferation of neoplastic mast cells in various organs, which can have either cutaneous or systemic presentation. Solitary cutaneous mastocytomas are most commonly seen in the pediatric age group but rarely present in adults. Histopathology of cutaneous mastocytoma is well described in the literature but only a few studies are available describing the cytomorphological features. We present a case of a 19-year-old female who presented with a 6-month history of a right supraclavicular single, 0.5 × 0.5 cm, well-defined, reddish-brown round nodule. The fine needle aspiration cytology (FNAC) smears were highly cellular showing monomorphic cells, predominantly dispersed singly and occasionally in small clusters. The cells were round to oval, with moderate cytoplasm containing coarse metachromatic granules. Toluidine blue stain and CD117 immunocytochemical stain confirmed the presence of mast cell granules. Based on the cytomorphology, staining, clinical history, and examination, a diagnosis of solitary cutaneous mastocytoma was rendered. FNAC plays a pivotal role in diagnosing mast cell tumors and even obviates the need for tissue biopsy in selected cases.

Diagnosis and Staging of Equine Neoplasia.

The diagnosis of neoplasia in the horse is both simple and extremely challenging, depending on the type of neoplasm and its location. Obtaining an accurate diagnosis of a neoplastic condition is key to formulating an appropriate treatment plan if possible or developing a palliative plan if curative treatment options do not exist. A combination of historical features, clinical examination findings, and diagnostic testing typically allow a working diagnosis of neoplasia to be made, with a definitive diagnosis requiring the identification of neoplastic cells in a sample or tissue.

Comparison of Peritoneal Cytology Results Before and After Resection in Gastric Cancer Patients.

OBJECTIVE: Peritoneal cytology is used to detect the peritoneal spread of gastric cancer and to assess survival rate. The aim of this study was to compare the risk factors, recurrence, and survival of gastric cancer patients with positive and negative peritoneal cytology before and after resection. MATERIALS AND METHODS: Patients with gastric cancer who underwent elective surgery were retrospectively analysed. The study covered a period between September 2018 and September 2020. After applying the exclusion criteria, 57 patients were included in the study. For the purpose of this study, peritoneal cytology was taken from the same three intra-abdominal regions before and after resection from patients with operable gastric cancer. RESULTS: Of the 57 patients included in the study, 36 (63.2%) were male patients and 21 (36.8%) were female patients. Preoperative or postoperative malignant cytology was detected in 12 patients (21.1%). Tumour diameter was larger in patients with preoperatively detected malignant cytology than in the patients with postoperatively positive malignant cytology (66.67 mm vs. 44.44 mm) (p = 0.006). The recurrence rate was higher in patients with preoperative and postoperative positive cytology than in those with negative cytology (p = 0.019). The survival of patients with preoperative malignant cytology was worse than the survival of patients with preoperative benign cytology (p = 0.011). A significant correlation was found between lymphovascular invasion (+), perineural invasion (+), T4, Stage 3 disease, number of malignant lymph nodes, and preoperative cytology positivity (p <0.05). CONCLUSION: In our study, we found that the preoperative cytology positivity is associated with lymphovascular invasion positivity, perineural invasion positivity, T4 tumour, Stage 3 disease, and the number of malignant lymph nodes. Postoperative positive cytology was not associated with the same variables. Because of the significant associations in preoperative positivity, fluid samples should be obtained immediately after the abdomen is open and before the tumour is manipulated. If possible, fluid samples should be taken from different quadrants, but if the sample is to be taken from a single quadrant, it should be taken from the pelvis.

Case report & review: Bilateral NIFTP harboring concomitant HRAS and KRAS mutation: Report of an unusual case and literature review.

Diagnosis and treatment of thyroid disease are affected by the wide range of thyroid cancer subtypes and their varying degrees of aggressiveness. To better describe the indolent nature of thyroid neoplasms previously classified as noninvasive follicular variant of papillary thyroid carcinoma (NI-FVPTC), the Endocrine Pathology Society working group has recently coined the term "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP). The purpose of this nomenclature change is to avoid patients the distress of cancer diagnosis and to decrease the overtreatment of thyroid nodules with a RAS-LIKE molecular profile similar to follicular adenoma. Consequently, the reclassification has a significant impact on thyroid nodule clinical care as well as histopathologic and cytopathologic diagnosis. This paper will focus on a unique case of Bilateral NIFTP harboring concomitant HRAS and KRAS mutation; we will also review the background, molecular features, and clinical implications of NIFTP as well as the factors behind the nomenclature update. It also seemed helpful to emphasize the impact of NIFTP on clinical practice to avoid overtreating nodules that could be safely managed with lobectomy alone. Actually, despite the diagnosis is postsurgery, a comprehensive preoperative evaluation may raise a suspicion of NIFTP and suggest a more careful plan for treatment. Here, we present a unique case of bilateral NIFTP after total thyroidectomy; subsequent molecular analysis revealed that the patient's right nodule harbored an isolated p.(Q61K) HRAS mutation, while the left a p.(Q61K) KRAS mutation. To the best of our knowledge, this is the first case report of this nature. The existence of simultaneous mutations highlights the occurrence of intratumoral heterogeneity (ITH) also in the context of FVPTC, which requires comprehensive investigation. The available information shows that NIFTP, identified in accordance with stringent inclusion and exclusion criteria, exhibits a very latent clinical behavior even in the face of conservative lobectomy, lacking of radioactive iodine therapy. However, it cannot be regarded as a benign lesion because there is a small but significant incidence of adverse events, such as lymph nodes and distant metastases. Currently, NIFTP can only be suspected before surgery: several efforts could be explored to identify key molecular, cytological, and ultrasonographic traits that may be helpful in raising the possibility of NIFTP in the preoperative context. Additionally, our discovery of simultaneous mutations within the same lesion strengthens the evidence of ITH even in FVPTC. Although the extent and biological impact of this phenomenon in NIFTP are still debated, a deeper understanding is essential to ensure appropriate clinical management.