AIMS Sentinel lymph node biopsy (SLNB) is an important component in the staging and treatment of cutaneous melanoma (CM). The medical literature provides only limited information regarding melanoma sentinel lymph node (SLN) histology. This report details the specific histological patterns of melanoma metastases in sentinel lymph nodes (SLNs) and highlights some key factors in evaluating SLNs fo...

Metastatic malignant melanoma has a wide spectrum of histopathologic patterns and often lacks melanin pigment. Without a known primary tumor, the diagnosis of metastatic malignant melanoma relies on a combination of morphology and immunohistochemical profile. Infrequently, commonly used markers for melanoma (S100, HMB45, Melan-A and Tyrosinase A) are negative. These cases pose critical diagnost...

Melanotic oncocytic metaplasia (MOM) of the nasopharynx is an extremely rare lesion, with only 21 cases reported in English literature to date. MOM typically occurs near the Eustachian tube opening in Asian men in their 60 s to 70 s. Here, we present a case of MOM in a 57-year-old Japanese man who is a heavy smoker. The patient did not have complaints; MOM was diagnosed incidentally as 4 flat e...

Epithelioid cell tumors presenting in the gastrointestinal tract are uncommon, but when they arise, arriving at a correct diagnosis is important. We report a case of anal malignant melanoma in an 82-year-old man who microscopically showed an epithelioid malignant tumor simulating a gastrointestinal stromal tumor. C-kit stain and Melan-A were diffusely and strongly positive, while HMB-45 was foc...

Epithelioid cell tumors presenting in the gastrointestinal tract are uncommon, but when they arise, arriving at a correct diagnosis is important. We report a case of anal malignant melanoma in an 82-year-old man who microscopically showed an epithelioid malignant tumor simulating a gastrointestinal stromal tumor. C-kit stain and Melan-A were diffusely and strongly positive, while HMB-45 was foc...

Our aim was to better understand and improve the accuracy of the preoperative diagnosis of intraspinal MM by a combined analysis of MR imaging and pathologic findings. All 5 patients had undergone unenhanced and contrast-enhanced MR imaging examinations. All tumor samples had immunohistochemical reactions to HMB-45, vimentin, S-100, EMA, and Leu-7 antibodies. All 5 cases were located in the int...

BACKGROUND From the first recognition of dysplastic nevi as a pathology per se, many debates have been raised and many histological and immunohistological studies have been conducted in order to establish the true significance of these lesions. Therefore, the aim of this study was to establish if there is a correlation between HMB-45, Melan A and Bcl-2 expression and the grade of dysplasia, as ...

Sir, A 13-year-old girl presented with complaints of a boggy mass on her left frontoparietal scalp since birth with thinning of the overlying hair. The lesion was first noticed at birth and gradually increased in size with age. On examination, a large (12 × 14 cm) soft to firm, bosselated, skin-colored plaque was seen involving the vertex and left frontoparietal scalp. The surface was irregular...

Signet-ring cell melanoma is an extremely rare variant of malignant melanoma. A 68-year-old male presented with a black nodule on the left thigh. Histopathological examination revealed proliferation of sheet-like or variable-sized nests of atypical melanocytes. Neoplastic cells showing signet-ring cell appearance, characterized by the presence of eccentrically located enlarged nuclei and abunda...