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A 32-year-old Japanese man presented to our hospital with a 5-month history of painful nodules on the fingers. He had previously developed left atrial myxoma followed by cerebral embolism and had undergone resection of the cardiac tumor 4 months before his first visit. His family history was unremarkable. Physical examination showed subcutaneous nodules 4 to 17 mm in size on all finger pads (Figure 1A and 1B). The tumors were smooth and as hard as cartilage. Hand radiographs showed irregularly shaped subcutaneous calcification corresponding to the nodules (Figure 2), and postoperative examination of the 3-dimensional computed tomographic reconstruction indicated the tumors more clearly (Figure 3). Physical examination and diagnostic imaging detected no tumors in other sites, including the lower extremities. The blood test results, including endocrine examination, were unremarkable. Figure 1. Subcutaneous nodules on all finger pads: the left …

A malignant epithelioid schwannoma occurred on the right second toe of a 30-year-old Japanese man. It was a firm, flesh-colored, benign-appearing nodule and measured 13 x 9 mm in diameter and 6 mm in height. To our knowledge, this is the first case of malignant epithelioid schwannoma occurring on the toe. Histopathology was characterized by a circumscribed nodule in the dermis that predominantly consisted of atypical large epithelioid cells with some spindle cells whose proliferation was similar to that of the Verocay bodies seen in ordinary schwannoma. Fontana-Masson staining demonstrated no melanin pigment in the tumor at the light microscopic level. The eosinophilic cytoplasm contained abundant glycogen and was positive for S-100 protein and HMB-45, as usually seen in melanomas. Electron microscopy revealed that there was an abundance of long-spacing collagen in the extracellular matrix, and the cells contained numerous dense-cored granules. But no definite melanosomes were observed in any stage. As far as we are aware, this is the first case of a malignant epithelioid schwannoma showing HMB-45 positivity.