Metastatic cutaneous leiomyosarcoma from primary neoplasm of the mesentery

A 31-year-old South Korean woman was referred to the dermatology department from the oncology department for the evaluation of a subcutaneous nodular lesion on the back. Three years before, she noted a palpable, fingertip-siz ed, nontender mass on her right lower abdomen. The mass had increased in si ze slowly. One year ago, she visited a local clinic and physical examinatio n revealed a 7 x 8 x 7cm, slightly tender, deep-seated mass on the right lo wer quadrant of the abdomen. The mass on the ilial mesentery was resected b y surgical exploration and tissue examination revealed leiomyosarcoma. She refused adjuvant chemotherapy. Approximately 3 months later, she re-visited the clinic with a tender, subc utaneous nodule on the back. Cutaneous examination revealed a solitary, 2 x 2 cm, well-defined, hard, movable, subcutaneous nodule on the upper back w ithout skin color change (Fig. 1). She complained of tenderness on touching the lesion. Histologic examination of a biopsy specimen showed irregularly arranged spindle cells scattered throughout the dermis. They were arranged in haphazardly oriented or interweaving fascicles. Most of the spindle cel ls possessed elongated nuclei with blunt ends and some cells had a polygona l outline with irregularly shaped nuclei. (Fig. 2). There were many mitoses : 3-4 per high-power (x 400) field. Immunohistochemically, smooth muscle ac tin and desmin were positive in most of the tumor cells (Fig. 3). S-100 rea ctivity was not observed. A diagnosis of metastatic leiomyosarcoma, was mad e. About 1 month later, computed tomography showed two, ill-defined, hetero geneous, low attenuation masses in the right lobe of the liver, suggesting liver metastasis. The patient was treated with chemotherapy for 2 months an d remains in good condition.