PRAME and Historical Immunohistochemical Antibodies Ki-67, P16, and HMB-45 in Ambiguous Melanocytic Tumors.

ABSTRACT: Ambiguous melanocytic lesions/tumors (AMLs) can be simply described as melanocytic neoplasms that cannot be differentiated as either a melanoma or a nevus. Preferentially expressed antigen in melanoma (PRAME) is a novel antibody that can help differentiate between nevi and melanomas. However, its usefulness remains controversial in AMLs. The aim of this study was to demonstrate the importance of PRAME and diagnostic auxiliary antibodies (Ki-67, p16, HMB-45) in the diagnosis of melanocytic lesions, especially in AMLs. This study included 52 ambiguous melanocytic lesions, 40 nevi, and 40 melanomas. All immunohistochemical studies were performed automatically using the Universal Alkaline Phosphatase Red Detection Kit. Different analytic approaches were used for each antibody based on the literature. Statistically, the multinomial forward stepwise elimination logistic regression analysis was used to create a statistical model to predict the diagnosis of melanocytic lesions based on clinical, morphological, and immunohistochemical data. PRAME positivity was very strong and diffuse in the melanoma group and statistically significantly higher than that of the AML and nevus groups. There was no statistically significant difference between the nevus and AML groups. The Ki-67 proliferation index and HMB-45 staining pattern provided valuable indications for distinguishing between these 3 groups. The P16 antibody was limited in supporting the differential diagnosis. Our statistical model showed that a high mitosis count, central pagetoid spread, and PRAME positivity increased the probability of melanoma against an AML diagnosis. This study showed the advantages of evaluating the PRAME antibody together with morphological features and other immunohistochemical markers (Ki-67 and HMB-45) in the differential diagnosis of melanocytic lesions.

The Comparative Dermal Stimulation Potential of Constant-Volume and Constant-Amount Diluted Calcium Hydroxylapatite Injections Versus the Concentrated Form.

INTRODUCTION: Biostimulation properties of diluted and hyperdiluted calcium hydroxylapatite (CaHA) injections have become increasingly popular. However, the existing data are insufficient to certify a particular dose-response pattern. OBJECTIVE: To assess and compare the dermal stimulation potentials of different concentrations of CaHA injections. MATERIALS AND METHODS: Two independent experiments (Experiment-1: constant injection volume vs Experiment-2: constant CaHA amount) included 4 study groups each, and these experimental groups were placed consecutively on the abdominal skin of a juvenile Yorkshire pig. Histopathological and immunohistochemical stainings were performed on punch biopsy materials collected 4 months after the injection day. RESULTS: The fibroblast count significantly decreased upon dilution from 1:3 to 1:19 in experiment 1 ( p = .000) but still higher than the control group. In experiment 1, the collagen density of the concentrated form was more elevated than the 1:19 dilution and the negative control groups ( p = .034 and .000, respectively) but similar to the 1:3 dilution ( p = .123). No significant difference was observed between the groups regarding collagen density with a standard amount of CaHA (0.2 mL, 30%) ( p > .05). CONCLUSION: Despite the efficacy being more pronounced till 1:3 dilution, hyperdiluted CaHA at any dilution ratio up to 1:19 can provide a higher fibroblast count than the negative control group.

Clinicopathologic Features and Prognostic Significance of Immunohistochemistry and In Situ Hybridization Based Molecular Classification in Gastric Carcinoma.

BACKGROUND/AIM: Gastric carcinoma (GC) is a highly heterogeneous disease with many subtypes that have different morphologic and molecular characteristics. In the current study, we analyzed immunohistochemical (IHC) and in situ hybridization (ISH) features of GCs and evaluated their association with prognosis and clinicopathological features. MATERIALS AND METHODS: Three hundred cases analyzed by IHC and ISH for microsatellite stability, p53, e-cadherin, HER2, PD-L1 expression, and Epstein-Barr virus (EBV) status. Cases were classified into five subgroups based on expression profile. The relationships between subgroups, clinicopathological features, and survival were determined. RESULTS: Ten (3.3%) cases were classified as EBV-associated, 45 (15%) as microsatellite instable (MSI), 73 (24.3%) as EBV-/microsatellite-stable (MSS)/epithelial-mesenchymal-transformation (EMT)-like, 75 (25%) as EBV-/MSS/ non-EMT-like/p53+, and 97 (32.3%) as EBV-/MSS/non-EMT-like/p53-. The MSI subtype had the best overall survival (OS). In contrast, the EBV-/MSS/EMT-like subtype had the poorest OS. The MSI subtype was also related with old age of the patient and antrum-corpus localized tumors, whereas the EBV-/MSS/EMT-like was associated with young age, larger tumor size, and advanced stage presentation. PD-L1 positivity is highly correlated with MSI and EBV-associated subtypes. CONCLUSION: Our data demonstrated a link between IHC/ISH characteristics of GC and clinical outcomes. IHC/ISH based molecular classification may be helpful in predicting the survival.

Dermatoscopic and Dermatopathologic Features of a 3-Year-Old Buried Polypropylene Suture.

ABSTRACT: Cutaneous foreign bodies are a well-known cause of delayed wound healing and complications such as abscesses, fistula formation, and secondary infections. Polypropylene sutures are widely utilized in cutaneous surgery because they easily travel through tissues while eliciting minimal tissue reactions. Despite these advantages, retained polypropylene sutures can cause complications. The authors report a case of a retained polypropylene suture that remained buried after a total excision 3 years prior. It started to cause cutaneous symptoms when the patient began exercising 1 week prior to presentation. The authors also examine the dermatoscopic and dermatopathologic features and other complications related to retained polypropylene sutures that have been reported in the literature.

Receptor Tyrosine Kinase Pathway and Infiltrating Urothelial Carcinoma.

Receptor tyrosine kinase pathway is frequently searched for cancer causing mutations in tumors. Emerging targeted therapies are gleam of hope for them. Infiltrating urothelial carcinoma can have many morphological aspects according to their differentiation/variants. To evaluate KRAS, BRAF, and PIK3CA mutations and HER2, EGFR, and p16 expression, we divided urothelial carcinomas into two groups: differentiated/variants (n = 12) and conventional (n = 12). We compared results with clinical, demographic, histopathologic features and survival rates. No statistically significant results could be obtained in the comparison of histopathologic properties/survival rates with mutation analysis and EGFR, HER2, and p16 status. Differentiated/variants urothelial carcinoma showed higher EGFR expression (P < 0.001). Glandular differentiation was the most frequent type, followed by squamous and sarcomatoid differentiation. We observed the most common mutation at KRAS with a propensity for urothelial carcinoma with glandular differentiation. More than one mutation/high protein expression was seen in some tumors. Targeted therapies for KRAS mutation can be effective at urothelial carcinoma with glandular differentiation. Heterologous expression of relevant proteins and genes can be a cause for targeted treatment obstacle. The determination of the molecular characters of tumors is a guide in creating targeted treatment algorithms and in choosing the patient.

Dermatopathological Correlation of Clinically Challenging Cutaneous Lesions: a Single Center Experience of 2184 Cases.

Introduction: Although a trained eye can easily identify typical skin lesions, histopathological examination and clinicopathological correlation are critical in challenging cases. Objectives: The primary objective is to organize the final diagnoses reached following clinicopathological consensus in clinically challenging cutaneous lesions, identifying the most common diagnostic scenarios encountered by dermatopathologists and discussing their diverse differentials submitted by clinicians. The secondary objective is to investigate how the case profile and clinician decision-making processes evolved during the COVID-19 pandemic. Methods: Skin and mucosa samples collected by the dermatology department between 2016 and 2020 were classified based on pathology reports. For frequent diagnoses, preliminary diagnoses stated by clinicians on pathology requisition forms were reviewed. The years preceding and following the first nationally reported COVID-19 case were compared to investigate the pandemic's impact on the distribution of dermatology and dermatopathology cases. Results: One thousand nine hundred and eighty-nine reports were classified into 4 major categories: inflammatory (49.8%), neoplastic (30.1%), other diseases (7.1%), and non-diagnostic (12.8%). We further classified inflammatory diseases based on major tissue reaction patterns and neoplasms based on cell origin. We analyzed the leading diagnoses in each category, discussed their differential diagnoses, and provided clinicians with clues to reduce errors in practice. Following the pandemic, the overall number of pathology reports and patient admissions dropped dramatically, with significant changes in case profiles. Conclusions: We presented and discussed the frequently encountered confounding cases to sketch the diagnostic landscape. In the authors' experience, clinicopathological correlation can increase the rate of reaching the diagnosis by up to 75.3%.

Melanocytes as the source of the increased melanisation in pigmented epithelial tumours: a holistic approach.

BACKGROUND: We aimed to elucidate the causes of the increased melanisation in basal cell carcinoma (BCC) and seborrheic keratosis (SK), and the role of melanocytes in this process. METHODS: This study was a retrospective-cohort study conducted in the pathology department of a university hospital between January 2019 and October 2020. Forty-nine SK and 30 pigmented BCC were included in our study. SRY-box transcription factor 10 (SOX10), CD68, and Masson-Fontana staining was used for analysis in all samples. A representative section of each specimen was photographed under ×400 magnification to facilitate the assessments of the morphology of the melanocytes and their following morphometric parameters: density, nuclear diameter, and distribution. The density of pigmented keratinocytes in the lesional epidermis was scored. The nuclear diameters of melanocytes located in the nonlesional epidermis, the density of the melanophages, and the presence or absence of ulceration and solar elastosis were also recorded. RESULTS: The morphometric findings confirmed a statistically significant increase in melanocyte density in the BCC group compared with that in the SK group (p < 0.001). Moreover, the nuclear minor diameters in the melanocytes of the BCC sections were significantly higher than those in the SK specimens (p < 0.001). The epidermal melanocytes were distributed diffusely in almost all BCC specimens (96.7%), whereas they were mainly limited to the basal layer in the majority of the SK sections (59.2%). The number of epidermal melanised keratinocytes with a score of 3 was significantly higher in the SK group (n = 31; 63.2%) than in the BCC group (n = 6; 20%) (p = 0.001), and they were the main cells representing the pigmented appearance of the tumours. No significant difference was found between both tumour groups in terms of their melanophage density scores (p = 0.206). DISCUSSION: This study is the first step towards an objective quantification of the melanocytes in pigmented epithelial tumours and may provide a morphological background for future studies on these skin lesions.

Rifaximine spacer application is not superior to local teicoplanin treatment in a rat model of osteomyelitis.

OBJECTIVE: Acute and chronic osteomyelitis generally require long-term antibiotic therapy and surgical debridement. Implant-associated osteomyelitis, particularly from methicillin-resistant Staphylococcus aureus (MRSA) strains, is difficult to treat. Rifaximin is an antibiotic derived from rifamycin which may be effective in the treatment of osteomyelitis in terms of its wide spectrum of action and pharmacological properties. The aim of this experimental study was to investigate the local efficacy of rifaximin in rat models with MRSA and implant associated osteomyelitis. METHODS: This study was carried out with 40 adult Wistar albino rats. The rats were randomly divided into 4 equal groups with 10 rats in each. An implant related MRSA osteomyelitis was created in the right tibia metaphysis of each rat by Norden's experimental osteomyelitis model. After 4 weeks, the implants of each tibia were removed and debridement was applied. Group 1 was designed as control group and no other treatment was applied other than debridement. Bone cement without any antibiotic was applied to Group 2, bone cement with teicoplanin was applied to Group 3 and bone cement with rifaximin was applied to Group 4. After 4 weeks from the second surgery, euthanasia was performed to the rats and the clinical, histopathological and microbiological results were compared. RESULTS: There was no statistically significant difference between the groups in clinical scoring. A statistically significant difference was found between the histopathological scores of Group 1 and Group 2 and the histopathological scores of Groups 3 and 4; the histopathological scores of Group 1 and Group 2 were found to be higher than Group 3 and Group 4. When the pre-and post-treatment colony numbers were compared, although there was a statistically significant difference between Group 3 and Group 2, no statistically significant difference was found between Group 4 and Group 1 results. CONCLUSION: In spite of its wide spectrum, the local efficacy of rifaximin in the treatment of osteomyelitis could not be demonstrated. This study shows the ability to shed light on some future comprehensive studies with the inclusion of infection markers.

Diffuse-type giant cell tumor: Pigmented villonodular synovitis of patellar fat pad.

Pigmented villonodular synovitis (PVNS) is a rare, relatively benign intra-articular lesion characterized by slowly progressing proliferation of the synovial tissue. It is most commonly observed in the knee joint. Localized and diffuse types are two types of PVNS depending on the synovial involvement. Arthroscopic and excisional resections are recommended as the treatment methods for the PVNS. Radiotherapy or chemotherapy can be adjuvant therapeutic options for the widespread masses. In this study, we presented a case of diffuse PVNS originating from the patellar fat pad.

STAT3, VEGF, and PSMA Expression Patterns in Malignant Peripheral Nerve Sheath Tumors, Malignant Melanomas, and Glioblastomas: Does Staining Percentage and Intensity Have an Effect on Survival?

Malignant peripheral nerve sheath tumors (MPNSTs), glioblastomas (GBMs), and malignant melanomas (MMs) are neural crest-originating aggressive tumors with a poor prognosis. Signal transducer and transcription activator 3 (STAT3) plays a role in many biological processes, including cell life and proliferation, the acute phase response, chronic inflammation, autoimmunity, metabolism, and cancer progression, It is also known to be a prooncogenic transcription factor. Vascular endothelial growth factor (VEGF) is one of the most potent proangiogenic stimuli ever identified. It mediates tumor neovascularization, and is associated with angiogenesis and lymphangiogenesis. The prostate-specific membrane antigen (PSMA) folate hydrolase I, despite its name, has been found in tissues other than the prostate. It is overexpressed in prostate cancer cells and several other cancers, and has the potential to be a target for radioligand therapy. We investigated the value of STAT3, VEGF and PSMA immunohistochemical expression patterns and their effects on survival in MPNSTs, GBMs, and MMs. Their expression patterns were evaluated in 25 MPNSTs, 27 GBMs, and 25 MM cases. All GBM cases stained positively for STAT3 and VEGF. In the other groups, the staining patterns were heterogeneous. None of the cases showed positive staining with PSMA. There was no statistically significant difference in survival between cases with differing VEGF and STAT3 staining patterns in the MPSNT and MM groups, but there was an increase in mortality as the VEGF score increased in the GBM group. The suppression of VEGF and STAT3 may be a promising avenue for treatment of MPNSTs, GBMs, and MMs, although further research is needed.

Anti-TNF agent etanercept augments UV-induced skin cancer development in SKH-1 mice.

BACKGROUND: Despite being employed in the treatment of inflammatory disorders for more than 20 years all over the world, data regarding photocarcinogenic risks of anti-TNF agents is scarce. OBJECTIVE: To assess photocarcinogenic potential of anti-TNF agents. METHODS: This was a placebo controlled, split-body (UVB-treated versus -untreated) study on mice. Treatment groups were infliximab (n = 11), etanercept (n = 11), cyclosporine (n = 11) and vehicle control (n = 11). Agents were introduced on the 10th week of phototherapy and continued through 24th week. The macroscopic, histological and immunohistochemical analysis of test sites were carried out. RESULTS: Overall 132 tumors were detected on test sites. All of these tumors developed on UV-exposed sides. Histologic examination of these tumors was compatible with keratinocytic neoplasia in 128, mastocytosis in 3, epidermal cyst in 1. Median tumor burden in the UVB exposed areas for ETN, IFX, CYC, and control groups were 14.91, 10.20, 6.28, and 3.14 cm2, respectively. ETN group demonstrated both higher tumor burden and keratinocytic neoplasia numbers than controls (p = .03, p = .025). Although there were 1.8 and 1.7 times more keratinocytic neoplasms in IFX and CYC groups compared to controls, these differences didn't reach statistically significant levels (p = .14; p = .19). CONCLUSION: This study points out to a significant photocarcinogenic potential of anti-TNF agent etanercept.

CD123 immunoexpression in cutaneous lupus erythematosus, polymorphous light eruption, pityriasis rosea, and mycosis fungoides.

INTRODUCTION: CD123-positive plasmacytoid dendrocytes are prominent in the infiltrate of cutaneous lupus erythematous. AIM: To determine the significance of the CD123 immunostain, which labels plasmacytoid dendritic cells (PDC), in cutaneous lupus erythematous (CLE), polymorphous light eruption (PLE), pityriasis rosea (PR) and mycosis fungoides (MF). MATERIAL AND METHODS: A total of 76 cases, including MF (n = 27), CLE (n = 19), PR (n = 19), and PLE (n = 11), were included in the study after reviewing their diagnostic clinical features and pathologic findings. The primary antibody against CD123 was performed in all cases. RESULTS: CD123+ immunostaining in PDCs was positive in all cases. The highest mean percentage was noted in CLE (15.2%), followed by PLE (15%), PR (8.8%), and MF (2%). Besides, the clustering of CD123-positive cells was significant in CLE and PLE compared to MF and PR. CONCLUSIONS: PDC may have an important role in the aetiology of PLE and CLE cases. CD123 is a useful marker for differentiating CLE and PLE from MF and PR.

Short- and long-term effects of rapamycin on ischemic damage and apoptotic changes in torsion of rat testes.

Rapamycin has antioxidant defense mechanisms and immune suppressive effects. To detect the short- and long-term effects of rapamycin on ischemic damage and apoptotic changes in torsion of rat testes, mature male albino Wistar rats (n = 48) were included in the study as control, sham, early torsion-detorsion (T/D), early rapamycin treatment, early rapamycin control, late T/D, late rapamycin treatment, and late rapamycin control. The right testis was rotated 720° in a clockwise direction during 4 h in operation groups. Rapamycin was administered orally three times: 30 min before detorsion and 24 and 48 h after detorsion. The animals were killed on the third day in early groups and on the tenth day in late groups after detorsion. Statistically significant differences among all groups were detected for SOD and TBARS, mean seminiferous tubule diameter (MSTD) and Cosentino's histologic score (CHS), caspase 3, bax, average number of apoptotic cells per tubule (ANPCT), and percentage of apoptotic tubule (PAT) values. ANPCT values ​​were 10% lower in the rapamycin treatment groups compared with the untreated T/D groups, and the PAT values ​​were also approximately 1.3 times lower. Although short-term usage of rapamycin may reduce to the tubular injury caused by I/R conversely to apoptosis in the testicular tissue after testicular torsion, rapamycin may have the potential to increase the long-term apoptosis with/without testicular torsion and a subsequent regression in fertility.

Systemic tranexamic acid promotes bone healing in a rat model of femur fracture.

OBJECTIVES: This study aims to investigate the effect of tranexamic acid (TXA) on the union of closed femoral fractures using radiological and histological methods in an experimental rat model. MATERIALS AND METHODS: This experimental study was conducted between June 2017 and February 2018. Closed femoral fractures were created in 36 male Wistar albino rats (age: three months [range, 2.5-3.5 months], weighing 200 grams [range, 180-220 grams]). Half of the animals randomly divided into two groups were administered intravenous single dose of TXA (30 mg/kg), whereas the animals in the control group did not receive any medication. The animals in the two groups were randomly divided into three groups with six animals each and cervical dislocation was performed at days 15, 30, and 45, and radiological and histopathological healing scores were compared. RESULTS: When the mean radiological scores of the TXA and control groups were compared, a statistically significant difference was found in favor of the TXA group at day 15 (p=0.019), but no significant difference was found in the mean scores on days 30 and 45 (p=0.138 and p=0.269, respectively). Histopathological examination also showed a statistically significant difference between the 15-day mean score values in favor of the TXA group ( p = 0. 017 ). CONCLUSION: The use of systemic TXA accelerates early bone formation and fracture healing.

Novel mutation identified in the DDB2 gene in patients with xeroderma pigmentosum group-E.

BACKGROUND: Xeroderma pigmentosum (XP) is a rare photosensitive syndrome, which is divided into eight complementation groups (XP-A to XP-G and XPV) and characterized by skin cancers diagnosed at early age. A family of seven members (age range between 5 and 47 years) with carriers of the novel nonsense mutation that causes XP-E type were included in the current study. METHODS: DNA was isolated from peripheral blood samples of the proband, and cancer predisposition genes were sequenced with next-generation sequencing. The demographic features and the laboratory, clinical, and histopathological findings of patients were evaluated. RESULTS: In the proband, squamous cell carcinoma was first diagnosed in the right-eye cornea at the age of 13 years and then in the left-eye cornea at the age of 15 years. Later, the patient was diagnosed with basosquamous cell carcinoma on the dorsum of the nose at the age of 18 years. After genetic analysis, a novel nonsense c.1063C>T(p.Arg355Ter) pathogenic variation that causes XP-E type was detected as homozygous in the DDB2 gene of the proband and her siblings, 11 and 5 years of age, and as heterozygous in her parents and a 22-year-old brother. CONCLUSION: Because of the occurrence of early termination codon, truncated nonfunctional proteins or proteins with deleterious loss or gain-of-function activities are synthesized in nonsense mutation. Thus, to avoid the development of pathological lesions, it is important that such patients with nonsense mutation stay away from agents that might cause DNA damage and develop an appropriate lifestyle according to this condition.

BRAF mutation, TERT promoter mutation, and HER2 amplification in sporadic or neurofibromatosis-related neurofibromas and malignant peripheral nerve sheath tumors: do these molecules have a signature in malignant transformation?

Peripheral nerve sheath tumors may occur sporadically or related to neurofibromatosis (NF). Unless the mechanisms of tumorigenesis in NF related malignant peripheral nerve sheath tumors (MPNST) are better understood, it remained unclear in sporadic cases. We aimed to investigate the genetic route for malignancy in both individuals with NF-1 and sporadic ones to open a way for targeted therapies in the future. We investigated the role of HER2 with Dual ISH DNA Probe Cocktail test, BRAF mutation (exon 15) and TERT promoter mutation frequency with Sanger sequencing method in respectively 25 sporadic neurofibromas, 25 NF-1 related neurofibromas and 25 MPNST cases from two institutes. Categorical data were analyzed and summarized as frequency and percentage. Statistical analysis was done with SPSS v.22 statistical package, and the statistical significance level was considered as 0.05. We identified TERT promoter mutation only in one sporadic MPNST (4%) and no BRAF mutation in any case. HER2 amplification is found in 10/25 (40%) MPNST cases. No mutations or gene amplification detected in neurofibromas (p < 0.001). MPNSTs are sarcomas with poor prognosis and limited treatment options. TERT promoter mutations and HER2 amplification may play a putative role in therapeutic purposes.

A rare localized giant cell tumor of the tendon sheath originating from the ligamentum mucosum: A case report.

Giant cell tumor of the tendon sheath (GCTTS) occurs most often in the hand and rarely in the feet, and as an extremely uncommon presentation in the knee joint. Case reports involving GCTTS in the knee joint generally describe it originating from the nearby anterior cruciate ligament, posterior cruciate ligament, patellar tendon, and medial plica. To the best of our knowledge, there are no previously reported case reports involving GCTTS originating in the ligamentum mucosum. In this article, we describe a 27-year-old male patient who was admitted to the orthopedic emergency room with a painful locked knee. He had severe pain that was worse with activity and a decreased range of motion. Magnetic resonance imaging (MRI) indicated massive swelling and a well-circumscribed lobulated intraarticular mass at the distal one third of the ligamentum mucosum. The mass was removed successfully with arthroscopic-assisted mini-open excision, and histological analysis subsequently diagnosed it as a localized type of GCSTT. The patient remained asymptomatic and a follow-up MRI two years after surgery did not show any recurrence of the lesion.

KRAS, BRAF, PIK3CA mutation frequency of radical prostatectomy samples and review of the literature.

OBJECTIVE: The molecular basis of prostate cancer is highly heterogeneous. Our study aimed to perform the mutation analysis of KRAS, BRAF, PIK3CA, and immunohistochemical (IHC) evaluation of EGFR, HER2, p16, and PTEN to demonstrate new areas for targeted therapies. METHODS: A total of 24 prostatectomy samples diagnosed with adenocarcinoma were analyzed by microarray hybridization. Also, these samples were IHC stained for EGFR, HER2, P16, and PTEN. The cases were divided into two groups based on low and high Gleason scores. All findings were compared with the clinicopathological parameters of the patients. RESULTS: While KRAS mutation was in 3/24 (12.5%) of our cases, BRAF and PIK3CA mutations were not detected. There was no significant difference between the groups in terms of KRAS mutation frequency. HER2 was immunohistochemically negative in all samples. There was no correlation between EGFR, P16 immunopositivity, and clinicopathological features. CONCLUSION: KRAS mutation frequency is similar to those in Asian populations. BRAF and PIK3CA mutation frequencies have been reported in the literature in the range of 0-15% and 0-10.4%, respectively, consistent with our study findings. HER2 immunoexpression is a controversial issue in the literature. EGFR and p16 expressions may not correlate with the stage.