Abstract BACKGROUND: Melanoma inhibitory activity is a protein secreted by melanoma cells and has been used as a tumor marker. Increased Melanoma inhibitory activity serum levels are related to metastatic disease or tumor recurrence. Currently there are no studies on Melanoma inhibitory activity and cutaneous melanoma involving Brazilian patients. OBJECTIVE: To evaluate the performance and feasibility of measuring Melanoma inhibitory activity levels in Brazilian patients with cutaneous melanoma. METHODS: Blood was obtained from ten patients with proved metastatic cutaneous melanoma (Group 1), 15 patients resected for cutaneous melanoma without metastasis (Group 2) and 5 healthy donors (Group 3). Melanoma inhibitory activity was measured using a commercially available ELISA kit. RESULTS: There was a statistically significant difference of Melanoma inhibitory activity levels between patients with and without metastasis (p=0.002), and between patients with metastasis and healthy donors (p=0.002). There was no difference between patients without metastasis and healthy donors (p=0.443). CONCLUSION: Melanoma inhibitory activity is a tumor marker for cutaneous melanoma and the Melanoma inhibitory activity-ELISA test can be easily performed. Patients with metastasis have increased Melanoma inhibitory activity serum levels when compared to patients without metastasis and healthy donors.

Mulher de 53 anos apresentou proptose lentamente progressiva no olho esquerdo. Tomografia computadorizada mostrou uma lesão na região temporal inferior da órbita esquerda, bem delimitada, arredondada, homogênea. O tumor era composto de células com citoplasma granular eosinofilico. Algumas das células possuíam grandes grânulos eosinofílicos circundados por um halo claro, conhecidos como corpos ovoides-pustulares de Milian or corpos de Bangle. O diagnóstico de tumor de células granulares foi estabelecido, confirmado pela imuno-histoquímica. Tumor de células granulares são neoplasias incomuns com predileção da região da cabeça e pescoço. O conhecimento das características histopatológicas típicas são cruciais para o correto diagnóstico.

A 53 year-old woman presented with a slowly progressive, painless proptosis OS. Computed tomography disclosed a round, homogeneous, well-delimited lesion in the inferior-temporal orbit. The tumor was composed of round cells with eosinophilic granular cytoplasm. Some of the cells had larger eosinophilic granules surrounded by a clear halo; known as pustulo-ovoid bodies of Milian or Bangle bodies. The diagnosis of a granular cell tumor was then established and confirmed by immunohistochemistry. Granular cell tumors are uncommon benign soft tissue neoplasms that have a predilection for the head and neck region. Awareness of the typical histopathological features is crucial for the correct diagnosis.