The utility of DNA methylation profiling in the diagnosis of un-, de- and trans-differentiated melanoma: a series of 11 cases.

AIMS: Melanomas are recognised for their remarkable morphological plasticity. Some tumours may lose conventional features and/or acquire non-melanocytic characteristics, referred to as undifferentiated, dedifferentiated and transdifferentiated melanoma. Despite this phenotypical variability, melanomas typically maintain their cancer driver aberrations, affecting genes such as BRAF, NRAS and NF1. Currently, little is known about whether the DNA methylation profile follows the loss or change of differentiation or is retained despite extensive morphological transformation. METHODS AND RESULTS: In this study we analysed 11 melanoma cases, comprising six males and five females, with a median age of 67 years, including five undifferentiated, four trans-differentiated and two de-differentiated melanomas. Undifferentiated and trans-differentiated tumours either arose in a patient with known melanoma and/or presented in the groin/axilla with molecular alterations consistent with melanoma. Cases with heterologous differentiation resembled chondrosarcoma, osteosarcoma, angiosarcoma and rhabdomyosarcoma both morphologically and immunohistochemically, while undifferentiated tumours resembled undifferentiated pleomorphic sarcoma. Methylome profiling was performed, and unsupervised clustering analysis revealed nine cases (five undifferentiated, three trans-differentiated and one de-differentiated) to cluster closely together with conventional melanomas from a reference set. Two cases clustered separately with a distinct group of conventional melanomas exhibiting H3K27me3 loss. CONCLUSIONS: Despite loss of differentiation and phenotypical plasticity, methylation patterns seem to be retained in undifferentiated, de-differentiated and trans-differentiated melanomas and represent useful diagnostic tools to enhance diagnostic precision in these diagnostically challenging cases.

Synchronous Double Primary Angiosarcoma Originating from the Stomach and Rectum: A Case Report and a Literature Review.

Angiosarcomas originating from the gastrointestinal tract are rare but highly aggressive tumors with poor prognosis. These tumors can be misdiagnosed as benign and malignant gastrointestinal tract lesions. The definitive histological diagnosis of angiosarcomasis made by pathologists based on immunohistochemical analysis demonstrating cluster of differentiation 31 (CD31), factor VIII-related antigen (FVIIIRAg), erythroblast transformation specific related gene (ERG), and cluster of differentiation 34 (CD34). Angiosarcomas are treated with a single or multimodality approach that may include resection, radiotherapy, chemotherapy, and palliative care, depending on the stage of disease and the condition of the patient. No matter the treatment option, metastasis and death rates are substantially highin patients with angiosarcoma. In this context, a 59-year-old male with synchronous double primary angiosarcoma arising from the gastric and rectum who presented with the complaint of abdominal pain and distention to the outpatient clinic is presented in this case report, along with a brief literature review.

Clinicopathological Features of Three Rare EWSR1::NFATC2 Sarcomas of Bone and Soft Tissues.

Certain undifferentiated round cell sarcomas displaying EWSR1::NFATC2 fusion have recently been reported, mostly in the bones. This report presents clinicopathological features of 3 additional EWSR1::NFATC2 fusion sarcomas of bone and soft tissues. We present 2 soft tissue and 1 bone tumors: A 62-year-old man with pain and a slowly growing, 8-cm-sized soft tissue mass in the anterolateral compartment of his right calf, along with multiple pulmonary metastatic lesions; a 63-year-old man with a 5-cm sized axillary mass of 4 months duration and a cystic renal mass; and a 53-year-old man with a complaint of leg pain was found to have a 2-cm diameter, intramedullary, lytic mass in the diaphysis of his left femur. Microscopic examination of the tumors in all patients revealed round to epithelioid cells arranged in cords and trabeculae in a myxohyaline stroma. Immunohistochemically, the tumor cells were positive for MIC2/CD99 (3/3), EMA (3/3), NKX3.1 (3/3), NKX2.2 (2/2), CD10 (2/2), and aggrecan (1/1), while negative for S100P and GFAP. Various keratins were also negative except focal AE1/AE3 positivity in the third tumor. By fluorescence in-situ hybridization, 2 tumors (#1 and #3) revealed EWSR1 gene rearrangement and amplification. Furthermore, 2 tumors (#1 and #2) displayed EWSR1ex8::NFATC2ex3 fusion with next-generation sequencing (NGS). The first patient was offered chemotherapy. However, he died of pulmonary metastasis. This report highlights the value of combining histopathological features and immunostains such as NXK3.1, NKX2.2, CD10, and aggrecan, along with EWSR1 testing for triaging these tumors for rare gene fusions by NGS that has prognostic implications.

Diagnostic Significance of Ki67 Staining Pattern in Benign Peripheral Nerve Sheath Tumors: An Additional Diagnostic Tool.

Introduction. Benign peripheral nerve sheath tumors involve mainly neurofibromas, schwannomas, and their variants. Ki67 is a widely used immunohistochemical marker that predicts the proliferation rate of tumors including the nerve sheath-derived neoplasms and it is helpful to differentiate them from their malignant counterparts. However, Ki67 score is not used in distinction of the benign peripheral nerve sheath tumors types from each other. Our aim is to contribute to the literature by identifying the hypothesized specific Ki67 staining patterns of benign peripheral nerve sheath tumors. Methods. Fifty-three tumors (distributed as follows: 26 schwannomas, 24 neurofibromas, and 3 hybrid schwannoma-neurofibroma tumors) from 49 patients were included in the study. Two researchers analyzed the slides independently. Tumors were classified according to their Ki67 staining patterns in 3 different groups: zonal (Z-Ki67), focal zonal or mixed (M-Ki67), and scattered Ki67 (S-Ki67). Results. There was a significant correlation among the types of benign peripheral nerve sheath tumor and the Ki67 staining patterns (P < .01). Level of inter-rater reliability was calculated as good (>0.7) and excellent (>0.8) according to 2 different calculations of kappa score. Conclusions. In conclusion, our study demonstrates that the Ki67 staining pattern may be used as an additional diagnostic tool in the diagnosis of benign peripheral nerve sheath tumors.

Expanding the Spectrum of the Soft Tissue Tumors with Kinase Gene Fusions: A Pediatric Spindle Cell Neoplasm Harboring MTAP-RAF1 Fusion.

Introduction: NTRK-rearranged spindled cell tumors have been increasingly recognized with the widespread use of molecular studies. We describe a pediatric spindle cell neoplasm with MTAP-RAF1 gene fusion that fits into this group. Case report: An 8-year-old girl presented with mandibular mass. Histopathologically, it was a moderate to increased cellular spindle cell tumor with mild-to-moderate nuclear pleomorphism, focal perivascular keloid-like collagen, that was positive for S-100 and CD34. MTAP-RAF1 fusion was detected by next generation sequencing, confirming a low-grade sarcoma with MTAP-RAF1 fusion that is presently included in the category of NTRK-rearranged spindled cell tumors. Discussion: MTAP-RAF1 fusion, in the spectrum of spindle cell neoplasms with kinase gene rearrangements, can occur in the pediatric age group.

Diagnosis of Lung Adenocarcinoma with Clear Cell Features in Pleural Effusion: Cytomorphologic Features, Immunocytochemical Studies, and Differential Diagnosis.

Clear cell adenocarcinoma (CCA) of the lungs is no longer referred to as a subtype in recent classifications of lung adenocarcinoma. Like signet ring features, clear cell features are regarded as cytological features rather than histological subtypes. Additionally, in serous fluids, adenocarcinoma metastasis with clear cell features is a diagnostic challenging entity due to other tumors that come to mindfirst during the differential diagnosis. Here we report a case, diagnosed as CCA of lung metastasis in pleural fluid and evaluated its differential diagnosis.

Comparison of Morphological Similarities and Differences between Liquid-Based Cytology and Conventional Techniques of Serous Effusion Cytology Specimens.

INTRODUCTION: The aim of this study is to discover a fast and efficient method for the diagnosis of serous effusion cytology specimens by comparing the cytomorphological features of SurePath (SP) smears and smears prepared by cytospin. After the macroscopic features of the incoming material were recorded, it was divided into 2 for conventional technique (CT) and liquid-based technique. Cytospin was used for CT and SurePath for liquid-based technique in this study. MATERIALS AND METHODS: 243 serous effusions (33 thoracentesis and 92 paracentesis fluids, 118 peritoneal lavage fluids) were investigated. After shaking the effusion gently, it was centrifuged for 5 min at 1,250 rpm for cytospin smear. SP smear was prepared according to the "BD PrepStain slide processor". Two smears were prepared with these 2 methods and then stained with Papanicolaou. The smears were examined under a light microscope in terms of fixation, background, cellularity, nucleus, and structural features. All statistical analysis of the data was performed using the SPSS 17.0 software. For each microscopic feature, the χ2 test was used to assess the significance of the relationship between cytospin and SP, and level of agreement in between the methods was assessed using the kappa statistic. RESULTS: A statistically significant difference was observed between the 2 methods in background (p < 0.001), cellularity (p < 0.001), nucleus features (p < 0.001), and structural features (p < 0.05). There was no significant difference in fixation. Low level of agreement was observed with the kappa statistic in fixation, background, and cellularity. Moderate level of agreement was observed in the nucleus and structural feature groups with the kappa statistic. DISCUSSION/CONCLUSION: Although there are advantages of liquid-based technique such as standardized fixation and cleaner background, since the cellular and background components required for morphological analysis and diagnosis are better preserved in cytospin, it is considered to be better to use liquid-based technique not alone but together with CT.

Clear cell sarcoma of soft tissue with eccrine differentiation: A case report and review of the literature.

Clear cell sarcoma of soft tissue (CCSST) is a deep soft tissue tumor presenting in the extremities of young adults. Histopathologically, nests and sheets of polygonal cells with clear to eosinophilic cytoplasm separated by fibrous septa as well as occasional "wreath-like" giant cells are visualized. However, CCSST has been noted to have atypical histopathological features, such as epidermotropism or myxoid differentiation, or occurrence at unusual sites. Here, we present a case of eccrine ductal differentiation in CCSST. The patient, a 21-year-old woman, presented with a lump of 10-year duration sized 3 × 5 cm on the plantar surface of the fourth and fifth interdigital spaces. There had been an increase in size as well as pain and redness over 6 years. Besides the characteristic findings, there were ductal structures in continuity with the upper dermis indicative of ductal differentiation. The tumor stained positively for S100, HMB45, and succinic dehydrogenase; ducts stained positively for epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA). CCSST was confirmed with cytogenetic analysis showing the translocation associated with EWSR1-ATF1 fusion gene. Therefore, ductal differentiation is a unique finding that should be considered when evaluating for CCSST.

Histopathological Comparison of 2-Octyl Cyanoacrylate and Primary Suturing for Tongue Lacerations.

OBJECTIVE: To enable tongue incisions to be repaired more easily, rapidly, and practically, particularly in pediatric patients by using 2-octyl cyanoacrylate (OCA) tissue adhesive. METHODS: A single linear incision was made on the midline dorsal part of the tongue. Twenty-four rats were randomly divided into the four groups: Group 1 (n = 6), OCA healing at day 5; group 2 (n = 6), OCA healing at day 21; group 3 (n = 6), Vicryl healing at day 5; group 4 (n = 6), Vicryl healing at day 21. In groups 1 and 2, OCA was applied to the incision site. The incisions of the rats in groups 3 and 4 were closed using Vicryl sutures. Histopathological examination was compared between and within the groups at day 5 and 21. RESULTS: The operation duration was significantly shorter with OCA than with Vicryl sutures(P < 0.001). Regarding the histopathological results, there were no differences between group 1 and group 3 in epithelial regeneration, inflammation, fibroblastic activity, edema, presence of giant cells, fibrin deposition, ulceration, abscess formation, and granulation tissue. However, moderate infiltration of acute inflammatory cells was significantly more frequent in group 1 than in group 3. At day 5, the incidence of moderate foreign body residue was significantly higher in group 1 than in group 3. No difference was observed between group 2 and group 4 at day 21 (P > 0.05). CONCLUSION: OCA is a practical, rapid, and effective method for repairing tongue lacerations. Although infiltration by inflammatory cells and foreign bodies increased in the early period, the long-term results of OCA were indistinguishable from those of suturing.