The expression of melanoma inhibitory activity on mast cells in child patients with cutaneous mastocytosis.

BACKGROUND: Cutaneous mastocytosis is a disorder characterized by the proliferation of mast cells in the skin. Melanoma inhibitory activity (MIA) is a serum marker for malignant melanoma. However, it has not been known on MIA expression of cutaneous mastocytosis. METHODS: We investigated the expression of MIA in 4 child patients with cutaneous mastocytosis immunohistochemically and serum MIA level in 1 patient by enzyme-linked immunosorbent assay. RESULTS: Histopathological examination revealed diffuse mast cell infiltration in the dermis. MIA was positive for infiltrating mast cells in all patients. Serum level of MIA was elevated in 1 patient. CONCLUSION: Although it was difficult to assess the significance of elevated serum levels of MIA in child patients, MIA was expressed on infiltrating mast cells in our study. Based on our findings, mast cell-derived MIA might be related to the formation of pigmented regions in cutaneous mastocytosis.

Metastatic basosquamous carcinoma detected by sentinel lymph node biopsy.

We describe a rare case of basosquamous carcinoma (BSC) in a 69-year-old man. He had noticed a pigmented nodule on his left thigh. Dermoscopic examination showed ulceration at the center and non-typical leaf-like areas at the periphery. Linear-irregular vessels were also seen. He underwent tumor excision in addition to sentinel lymph node biopsy (SLNB). Histopathological examination revealed both features of basal cell carcinoma (BCC) and squamous cell carcinoma. The sentinel lymph node was positive for tumor cells. Immunostaining for Ber-EP4 was focally positive for invasive tumor cells. Although complete inguinal lymphadenectomy had been performed, multiple in-transit metastases around the primary lesion and left iliac lymph node metastasis developed after the operation. It is considered that BSC has a worse prognosis than BCC with a potential for metastasis. Based on the findings of previously reported cases and our case, SLNB may be applied for certain high-risk cases including BSC larger than 3 cm in size and careful follow up is recommended for patients with BSC.

Novel morphological study of solar lentigines by immunohistochemical and electron microscopic evaluation.

Solar lentigines (SL) are hyperpigmented lesions generally seen in elderly people. Their pathogenesis has not been completely elucidated. We examined 75 cases of SL using routine histopathology and immunohistochemistry. In addition, seven cases were evaluated by electron microscopy. Histopathologically, we observed vacuolar changes in the dermoepidermal junction in 85% of the cases. Dermal melanophages were seen in 77% of the cases. The immunohistochemical expression rates in the epidermis for cytokeratin (CK)15, CK14, CK10, p63 and nestin were 76%, 100%, 100%, 100% and 17%, respectively. In 58 cases showing dermal melanophages, expression rates of CD163 and factor XIIIa on melanophages were 79% and 83%, respectively. Double positivity for both proteins was identified in 44 cases (75%). Ultrastructurally, vacuolar structures were seen in the cytoplasm of basal cells and upper dermis in all cases examined. We observed elimination processes of damaged basal keratinocytes, which were probably produced by ultraviolet (UV) irradiation, into the papillary dermis. The segregated damaged cell bodies containing melanin granules seemed to be phagocytosed by poorly immunostimulatory macrophages labeled immunohistochemically by CD163 and factor X IIIa, contributing to prolonged pigmentation of SL. In addition, repeated basal keratinocyte damages may be in association with altered CK and p63 expression patterns in the constituent cells of SL.