Detection of BRAFV600E mutation on papillary thyroid carcinoma and metastatic malignant melanoma by fine‐needle aspiration cytology

A genetic link between cutaneous melanoma and thyroid cancer (TC) has been identified. A high percentage of both melanomas and papillary carcinomas of the thyroid harbors a recurrent mutation (i.e., BRAF^V600E) in the BRAF oncogene. Herein, we report the case of a 65‐year‐old man with papillary TC and cutaneous malignant melanoma metastatic to masseter muscle, both characterized by BRAF mutation. This is one of the rare reports in which a complete molecular characterization has been performed. As the patients with papillary thyroid carcinoma have a higher risk of malignant melanoma and vice versa, continuous monitoring of such patients, with either of these tumors is necessary. Fine‐needle aspiration cytology is useful as shown in the present case. Diagn. Cytopathol. 2014;42:877–879. © Wiley Periodicals, Inc.     

Clinicopathologic features and immunohistochemical spectrum of 11 cases of epithelioid malignant peripheral nerve sheath tumors,including INI1/SMARCB1 results and BRAF V600E analysis

Epithelioid malignant peripheral nerve sheath tumor (MPNST) is a rare, relatively less chemosensitive sarcoma. We report clinicopathologic features of 11 epithelioid MPNSTs, including rare forms, along with INI1 immunostaining and BRAF V600E mutation results. BRAF V600E mutation was tested by Real‐time polymerase chain reaction (PCR) technique. Eleven tumors occurred in six men and five women (M:F ratio = 0.85:1) within an age range of 5–73 years (average = 44), mostly in lower limbs (five), followed by upper limbs (four). Tumor size (n = 6), varied from 3.1 to 15 cm (average = 8.3). Histopathologically, most tumors were multilobular, characterized by epithelioid to round‐shaped, malignant cells, along with spindle cells (three cases), “rhabdoid‐like” cells (seven cases) and pleomorphic giant cells (single case). By immunohistochemistry, tumor cells were positive for S100 protein (11/11) (100%), EMA (3/7) (42.8%), pan CK(2/7) (28.5%), and HMB45 (1/11) (9%), while these were negative for Melan A (0/11) and INI1 (3/11), including a single tumor, displaying HMB45 positivity. BRAF V600E mutation was positive in 1/8 cases, that lacked melanocytic marker expression. All patients (n = 5) were treated by surgical resection. During follow‐up (n = 8, median duration = 23 months), four patients developed tumor recurrences and four developed metastasis, mostly to lymph nodes (3). Finally, four patients were alive with disease, two were alive with no evidence of disease, and two patients died of disease. Epithelioid MPNSTs have a diverse histopathologic spectrum. Loss of INI1 is useful, including in identifying rare forms of epithelioid MPNST, displaying melanocytic differentiation. Most tumors are treated by surgical resection. Loss of INI1 and the presence of BRAF V600E mutation in some cases raises future possibility of exploring targeted therapy in those, rare epithelioid MPNSTs.