Cytologic features of differentiated high-grade thyroid carcinoma: A multi-institutional study of 40 cases.

BACKGROUND: Differentiated high-grade thyroid carcinoma (DHGTC) is recently recognized by the World Health Organization (WHO) as a subgroup of thyroid carcinomas with high-grade features while retaining the architectural and/or cytologic features of well-differentiated follicular-cell-derived tumors. The cytomorphology of DHGTC is not well documented despite potential implications for patient triage and management. METHODS: The pathology archives of six institutions were searched for cases diagnosed on resection as "high-grade thyroid carcinoma" using WHO criteria. The fine-needle aspiration (FNA) cohort represents a 10-year period (2013-2023); all were reviewed to confirm DHGTC classification. The corresponding FNAs were assessed for 32 cytomorphologic features. RESULTS: Forty cases of DHGTC with prior FNA were identified. The mean patient age was 64.2 years. The average lesion size was 4.9 cm, and the majority demonstrated a TI-RADS score of 4 or 5 (95.2%). Three main high-grade subsets of DHGTC based on corresponding histology included papillary thyroid carcinoma (65%), follicular carcinoma (22.5%), and oncocytic carcinoma (12.5%). Over 97% of FNA cases were classified as Bethesda category IV or above. Approximately 25% of DHGTC showed cytologic features that included marked cytologic atypia, increased anisonucleosis, large oval nuclei, mitotic activity, or necrosis (p < .05); 68% of DHGTC cases were associated with high-risk molecular alterations. TERT mutations occurred in 41%, of which 89% of these were associated with a second mutation, usually RAS or BRAF p.V600E. CONCLUSIONS: Cytology has a low sensitivity for DHGTC, although a subset of DHGTCs have cytologic features raising the possibility of a high-grade thyroid carcinoma. Other findings include high-risk molecular changes and clinicopathologic features such as older patient age and larger lesion size.

Metastatic prostate cancer diagnosed by fine-needle aspiration: Contemporary cytopathologic and biomarker assessment with clinical correlates.

INTRODUCTION: The diagnosis of metastatic prostatic cancer (MPC) by fine needle aspiration (FNA) can usually be rendered by typical cytomorphologic and immunohistochemical (IHC) features. However, MPC diagnosis may be complicated by transformation to atypical phenotypes such as small cell carcinoma, typically under pressure from androgen deprivation therapy (ADT). Predictive and prognostic biomarkers can also be assessed by IHC. This study illustrates how careful assessment of cytologic and biomarker features may provide therapeutic and prognostic information in MPC. DESIGN: We reviewed our anatomic pathology archives for MPC diagnosed by FNA from January 2014 to June 2021. Clinical histories, cytology slides, and cell blocks were reviewed. Extensive IHC biomarker workup was performed, including markers of prostate lineage, cell-cycle dysfunction, Ki-67, neuroendocrine markers, PDL1, and androgen receptor splice variant 7. Cases were reclassified into three categories: conventional type, intermediary type, and high-grade neuroendocrine carcinoma (HGNC). RESULTS: Eighteen patients were identified. Twelve had conventional MPC, including six of six ADT-naive patients. Six of twelve (50%) with prior ADT were reclassified as intermediary or HGNC. Four intermediary cases included two with squamous differentiation and two with pro-proliferative features. Two HGNC cases had typical small cell carcinoma cytomorphology. Expression of PDL1 was identified in two cases and ARv7 in three cases. Five of five intermediary and HGNC patients died of disease versus six of eleven with with conventional type. CONCLUSIONS: Aggressive cytomorphologic variants were commonly identified in patients with prior ADT. Identification of nonconventional cytomorphology and increased proliferation can provide important prognostic information. Recognition of these changes is important for an accurate diagnosis, and the identification of high-grade variants can affect therapeutic decision-making. Clinically actionable biomarkers such as PDL1 and ARv7 can be assessed by IHC.

Approach to Fine Needle Aspiration of Adrenal Gland Lesions.

Adrenal gland lesions are present in 1% to 5% of patients and are most commonly identified incidentally on abdominal imaging. Fine needle aspiration (FNA) cytology plays an important role in the initial workup of adrenal gland nodules, especially in patients with a known history of malignancy. The most common reason for adrenal gland FNA is to differentiate benign adrenal lesions, such as adrenal cortical adenoma, from metastatic malignancy. However, there is a significant cytomorphologic overlap between primary and metastatic adrenal neoplasms. This review focuses on the current state of adrenal gland FNA cytology, with an emphasis on distinguishing adrenocortical adenoma from carcinoma and adrenal cortical neoplasms from metastatic malignancies. The role of immunohistochemistry in specifically diagnosing adrenal neoplasms is discussed. Proposed diagnostic classification systems for adrenal gland FNA cytology are also described.

Salivary gland neoplasms with basaloid features in the era of the Milan system for reporting salivary gland cytology: Classification and interobserver agreement.

BACKGROUND: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has been shown to have moderate to good reproducibility for categorization of salivary gland fine-needle aspiration (FNA) specimens. Less is known of its accuracy and interobserver reproducibility for categorization of the diagnostically difficult group of basaloid neoplasms. METHODS: Forty-five salivary gland specimens with a basaloid morphology (pleomorphic and monomorphic adenomas and adenoid cystic carcinomas) were independently assigned by seven cytopathologists to one of the MSRSGC categories. Interobserver agreement was assessed for average agreement, chance expected agreement and by Cohen's κ and diagnostic accuracy. Correlation of the salivary gland neoplasm of unknown malignant potential (SUMP) category with histologic diagnosis and benign or malignant designation along with interobserver reproducibility were calculated. RESULTS: Average observed agreement for assignment to the MSRSGC was 46% and Cohen's κ = 0.2%. The SUMP category did not correlate with tumor type or with the benign or malignant nature of the neoplasm. Diagnostic specificity and sensitivity were 92% and 100% for consensus diagnosis, but were 76% and 77% for individual diagnoses. CONCLUSION: The interobserver agreement in categorizing basaloid neoplasms by the MSRSGC is poorer than for salivary gland lesions overall. This reflects the difficulty in diagnosing basaloid neoplasms. Nonetheless, diagnostic accuracy appears similar to that of salivary gland neoplasms as a whole.

Cytologic findings in effusions from patients with SARS-CoV-2 infection.

INTRODUCTION: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is associated with "flu-like" upper respiratory tract symptoms and pneumonia. Body cavity effusions develop in a subset of patients with advanced disease. Although SARS-CoV-2 is known to be present in certain body fluids (eg, blood) of COVID patients, it remains unclear if body cavity fluids are sites of infection. Our aim was to characterize the cytologic and clinical findings in COVID-19 patients with effusions. MATERIALS AND METHODS: A record search for all cases of body cavity effusion cytology in SARS-CoV-2 positive patients from March 1, 2020, to September 1, 2020, was performed. Clinical history, fluid chemical analysis, cytologic findings, and patient outcomes were recorded. All cytology slides were reviewed. In situ hybridization (ISH) targeting SARS-CoV-2 spike protein transcript (V-nCoV2019-S) was performed on cell block material in all cases. RESULTS: A total of 17 effusion cytology cases were identified among 15 COVID patients, including 13 pleural, 2 pericardial, and 2 peritoneal. Most (13 of 15) patients were hospitalized for COVID complications. Eight patients died during hospitalization, 7 from COVID complications. All fluids were transudative by protein criteria. Lymphocytic or histiocytic inflammation predominated in 12 of 17 cases. Five exhibited hemophagocytosis. No viral cytopathic changes or extra-medullary megakaryocytes were seen. Viral RNA was not detected in any case by ISH. CONCLUSIONS: Body cavity effusion is an ominous finding in patients with advanced COVID-19 disease. Such effusions tend to be transudative with lymphohistiocytic inflammation, and commonly exhibit hemophagocytosis, an otherwise rare finding in effusion cytologies. No direct infection of cellular elements by SARS-CoV-2 was identified by ISH.

Fine needle aspiration of salivary gland carcinomas with high-grade transformation: A multi-institutional study of 22 cases and review of the literature.

BACKGROUND: High-grade transformation (HGT) is a rare process whereby conventional low- to intermediate-grade salivary gland carcinomas (SGC) transform into high-grade, poorly or undifferentiated malignancies with focal or complete loss of their conventional histomorphologic features. Because tumors with HGT are associated with a worse prognosis than their conventional counterparts, preoperative recognition of HGT may be of benefit for optimal patient management. Using a multi-institutional approach, we describe the largest fine needle aspiration (FNA) cohort of salivary gland carcinomas with HGT. METHODS: The archives of 9 large academic medical centers were searched, and 22 cases of SGC with HGT were identified by surgical excision accompanied by preoperative FNA. Clinical and cytomorphologic features were retrospectively reviewed. RESULTS: The male-to-female ratio was 14:8, and the mean patient age was 60.2 years. The average tumor size was 3.6 cm, and 19 cases were from the parotid gland. Acinic cell carcinoma with HGT was the most common tumor subtype, comprising 12 cases with HGT, followed by adenoid cystic carcinoma, secretory carcinoma, and other subtypes. Eighteen cases were classified as malignant; however, a specific diagnosis of HGT was not made. Sixteen cases contained a high-grade cytologic component, and 7 cases had a mixture of both conventional and high-grade components retrospectively. CONCLUSIONS: SGC with HGT should be considered in the differential diagnosis of a salivary gland aspirate exhibiting high-grade cytomorphologic features. The presence of distinct tumor populations, conventional and high-grade, should prompt consideration of HGT, especially when the conventional component is acinic cell carcinoma or adenoid cystic carcinoma.

Thyroid paraganglioma: A diagnostic pitfall in thyroid FNA.

BACKGROUND: Thyroid paragangliomas are extremely rare and often are misdiagnosed by preoperative fine-needle aspiration (FNA) because their cytologic features overlap with those of other thyroid neoplasms. The objective of this study was to review the cytomorphology in a series of thyroid paragangliomas and correlate the findings with histopathology. METHODS: Five thyroid paraganglioma cases that underwent FNA were reviewed. Their clinical presentation, radiology features, cytomorphology, ancillary tests, and histopathology were analyzed. RESULTS: All patients were women with an average age of 49 years (age range, 35-61 years) and presented with an asymptomatic, solitary thyroid nodule. Radiologically, these nodules (size range, 1.8-3.0 cm) were well circumscribed, hypoechoic, and hypervascular. FNA smears showed clusters of loosely cohesive, medium-to-large epithelioid cells with clear-to-eosinophilic and occasionally foamy cytoplasm that had indistinct cytoplasmic borders. The nuclei were round to oval with focal nuclear membrane irregularities, inconspicuous nucleoli, focal marked anisonucleosis, and occasional intranuclear pseudoinclusions. Naked nuclei, variable numbers of plasmacytoid cells, multinucleated giant cells, and sustentacular cells were present in the background along with blood vessels and lymphocytes. Cytology diagnoses were incorrect and included follicular neoplasm (n = 4) and follicular lesion of undetermined significance (n = 1). Final histopathology with immunohistochemistry revealed conventional paraganglioma (n = 3) or sclerosing paraganglioma with invasive features (n = 2). CONCLUSIONS: All thyroid paragangliomas were misdiagnosed on FNA as follicular neoplasms, in part because of the rarity of these tumors in this location and cytomorphology mimicking follicles. The absence of colloid, the presence of naked nuclei, focal marked anisonucleosis, and the presence of sustentacular cells are important cytology clues.

Increasing prevalence of HPV in oropharyngeal carcinoma suggests adaptation of p16 screening in Southeast Asia.

BACKGROUND: Human papillomavirus (HPV) is etiologically linked to increasing oropharyngeal squamous cell carcinoma (OPSCC) rates in the Western world. However, the role of HPV in Southeast Asia, a high incidence region, hasn't been assessed. METHODS: 96 formalin-fixed, paraffin-embedded (FFPE) tissue blocks and corresponding patient data were obtained from Srinagarind Hospital, Thailand from 2012-2017. DNA from areas of 70 %+ cellularity were genotyped using polymerase chain reaction (PCR) and stained for p16, a surrogate marker for HPV. Inverse probability weights based on data from the hospital-based cancer registry were used in statistical analyses. Adjusted linear regression was used to assess changes in OPSCC HPV prevalence and conduct projections. Kaplan-Meier and Cox proportional hazard models were used to determine HPV-specific survival differences. RESULTS: 14 patients exhibited monoinfection with HPV16, two with HPV18 and one was HPV16/18 coinfected. PCR results were in agreement with p16 staining. On average, HPV + patients were more likely to have tonsil cancer (p-value:0.002). HPV prevalence increased by 2% annually (pvalue: 0.01), from 16 % in 2012 to 26 % in 2017. At the current rate, OPSCC HPV positivity will exceed 50 % by 2030. HPV positivity was shown to be protective in Kaplan-Meier (log-rank p = 0.02) and sex, age and stage adjusted Cox models (HR:0.34 [95 %CI:0.22, 0.52]). CONCLUSION: Given the increased prevalence and similarities in presentation of HPV + OPSCC to those observed in Western countries, the data suggest the adaptation of p16 staining and subsequent restaging of OPSCC tumors as suggested by the American Joint Committee on Cancer in Southeast Asia.

Low-grade squamous intraepithelial lesion on Papanicolaou test: follow-up rates and stratification of risk for high-grade squamous intraepithelial lesion.

INTRODUCTION: Low-grade squamous intraepithelial lesion (LSIL) Papanicolaou test is associated with moderate risk of high-grade squamous intraepithelial lesion (HSIL) at colposcopic biopsy. High-risk human papillomavirus (hrHPV) cotesting risk stratifies patients with LSIL Papanicolaou test, with higher rates of HSIL for those hrHPV+. hrHPV genotyping is not considered in current LSIL management algorithms. MATERIALS AND METHODS: We performed a 2-year retrospective review of LSIL Papanicolaou tests in patients 25 to 65 years old to assess rates of follow-up and HSIL at biopsy. Patient age, hrHPV cotest and genotype results, prior screening results, and follow-up testing for 3 years were recorded. RESULTS: A total of 71.5% (376 of 526) of patients had at least 1 follow-up colposcopic biopsy; 18% had HSIL on follow-up, including 20% of hrHPV+ and 12% of hrHPV-. HSIL at biopsy was most common when HPV16/18 was present (32%) and when multiple subtypes were detected (46%) versus when non-16, non-18 hrHPV alone was present (16%) or hrHPV was negative (12%). Of those hrHPV-, 5 of 22 (23%) with a prior screening abnormality had HSIL versus 1 of 27 (4%) for those without prior abnormalities. Follow-up occurred more commonly for hrHPV+ cotests (82%) than hrHPV- cotests (54%). No differences in follow-up rate based on hrHPV genotyping was seen. CONCLUSIONS: The highest HSIL rates were seen when HPV16/18 was present (32%). HSIL rates were similar for those hrHPV- (12%) and non-16, non-18 hrHPV+ (16%). Follow-up was more common for those hrHPV+, but genotype results did not impact follow-up rates. Past screening results may impact risk of HSIL for hrHPV- cases.

Fine-Needle Aspiration Cytology of Cellular Basaloid Neoplasms of the Salivary Gland.

CONTEXT.­: Cellular basaloid neoplasms of the salivary gland represent a diverse group of benign and malignant neoplasms with significant cytomorphologic overlap on fine-needle aspiration cytology. All are marked by the presence of monotonous and usually bland basaloid epithelium. Distinction between basaloid neoplasms on fine-needle aspiration cytology is based on the presence or absence of additional features, including a second cell population (eg, myoepithelial cells), an acellular stromal component, and/or cytologic atypia within the basaloid epithelium. This review highlights the cytomorphologic features of the most common cellular basaloid neoplasms of the salivary gland, with an emphasis on classification and subclassification within the Milan System. OBJECTIVE.­: To provide a comprehensive review of the cytologic features of basaloid epithelial neoplasms of the salivary gland, with an emphasis on classification within the Milan System for Reporting Salivary Gland Cytopathology. DATA SOURCES.­: Peer-reviewed literature, recent textbooks, and personal experiences of the author. CONCLUSIONS.­: Some basaloid neoplasms, in particular pleomorphic adenomas and adenoid cystic carcinomas, may have characteristic findings on fine-needle aspiration that allow for definitive diagnosis. In other cases, however, fine-needle aspiration can confirm a neoplastic basaloid process, but specific classification of a benign or malignant neoplasm cannot be rendered. The Milan System for Reporting Salivary Gland Cytopathology acknowledges this difficulty, and recommends benign or malignant classification only when definitive diagnostic features of a specific neoplasm are present. For indeterminate cases, the subcategorization of salivary neoplasm of uncertain malignant potential is recommended.

The role of peritoneal washings in the diagnosis of endometriosis.

Endometriosis, the presence of endometrial tissue outside the uterine corpus, is a common finding in reproductive age women. It is classically diagnosed based on the presence of at least two of the following elements: endometrial glands, endometrial stroma, and hemosiderin-laden macrophages (HLMs). Although a common finding in surgical pathology specimens at the time of gynecologic surgery, there is little literature on the role of pelvic washings in diagnosing endometriosis. Our study aimed to examine the characteristics of endometriosis in pelvic washings at the time of gynecologic surgery. We report nine cases of endometriosis diagnosed on pelvic washing. Two had a reported history of endometriosis. Four had endometriosis on the concurrent surgical pathology specimen. Liquid-based cytology was diagnostic of endometriosis in seven patients, including five with glandular cells and HLMs and two with glandular cells, HLMs, and endometrial stromal cells. Cell block was diagnostic of endometriosis in eight patients, including four cases with intact fragments of endometrial glands and stroma. Three cases showed glandular cells and HLMs, while one showed separate fragments of glandular cells and stromal cells. Pelvic washings increased the diagnostic yield for endometriosis at the time of gynecologic surgery, as only four out of nine cases had endometriosis diagnosed on surgical pathology. Cell block in particular aids in the diagnosis, since intact glandular and stromal fragments frequently can be identified.

Cytologic findings of acute leukemia in bronchoalveolar lavage fluid.

Bronchoalveolar lavage (BAL) is often performed in patients with acute leukemia developed with respiratory failure or pulmonary infiltrates. Patients usually undergo BAL to rule out infection. Occasionally, however, leukemic infiltrate may be detected. We present a series of 11 cases in which the diagnosis of leukemia was made on the BAL material. We retrospectively reviewed all BAL samples from January 1, 2006 to December 31, 2008. There were a total of 1,130 cases, of which 139 showed malignant cytology, including 10 with leukemia. Sixteen samples were unsatisfactory and 904 were benign, of which 32 had identifiable microorganisms. In additional to the 10 leukemia cases identified, two more were reviewed after the search criteria. The 12 patients (seven men, five women) ranged from 22 to 75 years old. All patients had previously biopsy-proven leukemia [two acute myelomonocytic leukemia, two acute promyelocytic leukemia, two acute myeloid leukemia (AML) with inv16, two therapy-related AML, one acute monocytic leukemia, one chronic myeloid leukemia in blast face, one AML with maturation, one myelodysplastic syndrome with excess blasts, and one large granular leukemia]. Four had a prior diagnosis of myelodysplastic syndrome. The time from initial diagnosis of leukemia to BAL ranged from 1 to 233 days, with 8 of 10 occurring within 8 days of diagnosis. Symptoms that prompted BAL included shortness of breath/hypoxia (8), fever (3), chest pain (2), and cough (2). Chest X-rays in all cases revealed opacities or consolidations mimicking an inflammatory process. Seven patients subsequently died, while three were alive, and, in remission, and two were lost to follow-up. The presence of a leukemic infiltrate can mimic infection. BAL is a relatively safe and useful diagnostic tool in this setting for differentiating a leukemic infiltrate from an infection/inflammatory infiltrate. The prognosis of patients with lung involvement of acute leukemia is poor.

Ancillary studies in determining human papillomavirus status of squamous cell carcinoma of the oropharynx: a review.

Squamous cell carcinoma (SCC) of the oral cavity and pharynx represents the sixth most common form of malignancy worldwide. A significant proportion of these cases are related to human papillomavirus (HPV) infection. In general, HPV-associated SCC is more commonly nonkeratinizing and poorly differentiated, whereas non-HPV-associated SCC is typically keratinizing and moderately differentiated. Nevertheless, significant overlap in morphology is seen between these two forms of SCC. The purpose of this paper is to highlight the utility of ancillary studies in the establishment of HPV status of oropharyngeal SCC, including p16 immunohistochemistry, high-risk HPV in situ hybridization, polymerase chain reaction, and newer HPV detection modalities.

Fine-needle aspiration diagnosis of a metastatic adult sclerosing rhabdomyosarcoma in a lymph node.

Adult sclerosing rhabdomyosarcoma (ASRMS) is a rare variant of rhabdomyosarcoma with a characteristic histological appearance of small, round cells in a dense, hyalinized stroma. Although nodal metastases of soft-tissue sarcomas are considered uncommon, up to 5% overall are associated with lymph node metastases. Nonetheless, there is little literature on the cytologic characteristics of metastatic soft-tissue sarcomas in lymph nodes, and to our knowledge, there are no reports of nodal metastasis of ASRMS diagnosed by fine-needle aspiration (FNA) cytology. We report here a 55-year-old woman who presented with a right thigh mass and associated ipsilateral inguinal lymphadenopathy. Biopsy of the mass revealed a uniform population of small, round cells in a dense, sclerotic background. A diagnosis of ASRMS was rendered. Subsequently, the patient underwent FNA of an enlarged inguinal lymph node, which revealed an identical population of small, round cells in a dense, myxoid background. This case highlights the cytologic features of a rare form of rhabdomyosarcoma, and emphasizes the utility of FNA in the assessment of lymphadenopathy in the setting of a soft-tissue sarcoma.