Cutaneous metastasis from a presumed signet-ring cell carcinoma in a 10-year-old child.

Cutaneous metastases of internal malignancies are very rare in children. In this group, neuroblastoma, leukaemia and lymphoma are the most common malignancies that may develop metastases or neoplastic infiltrates to the skin. Carcinomas have infrequently been reported in children, and cutaneous metastases from carcinoma in this group have not been described. A 10-year-old girl presented with an erythematous plaque on the left hemithorax. Histopathological findings revealed grouped signet-ring cells within the lumina of lymphatic vessels in the dermis. Immunohistochemical examination confirmed the epithelial origin of the tumour. Despite an exhaustive search, the primary site could not be determined. This exceptional observation is, to the best of our knowledge, the first report of cutaneous metastasis from occult carcinoma in a child.