Syringoid eccrine carcinoma with apparently aggressive transformation: case report and review of the literature

A 65-year-old man presented with a 20-year history of a lesion on his lower abdomen. The lesion had started as an indolent papule that slowly developed to form an extensive plaque. Physical examination revealed a flat-topped, elevated, well-demarcated, erythematous plaque measuring 7 cm × 5 cm in diameter (Fig. 1). The lesion had an elastic, hard induration beneath the plaque and was fixed to the underlying tissue. Inguinal lymphadenopathy was present. Hematologic and biochemical investigations were all within the normal ranges. The patient underwent incision biopsy. Figure 1. Clinical appearance of the lesion. An indurated plaque can be seen on the lower abdomen Download figure to PowerPoint A biopsy specimen, measuring 2.7 cm, revealed that the tumor was located in the dermis, and consisted of solid nests and small cords in a dense fibrocollagenous stroma. The tumor located in the upper dermis consisted mainly of solid nests with calcified central necrosis (Figs 2 and 3). The tumor located in the deep dermis consisted of small cords forming luminal, tubular, and tadpole-shaped structures, resembling those of syringoma (Figs 2 and 3). Solid tumor nests consisted of tumor cells which were basaloid and polymorphic, with hyperchromatic nuclei. A few mitotic figures were observed. A palisading arrangement of tumor cells was not observed at the periphery of the solid tumor nests. Keratinous cysts and follicular differentiation were not observed. No apocrine differentiation, such as decapitation secretion, was observed. There were no connections between the tumor nests and the epidermis. The extent of tumor invasion could not be determined from the biopsy specimen because the tumor had spread beyond the edges of the excision. Immunohistochemical analysis showed diffuse nuclear and cytoplasmic positivity for S-100 protein (1 : 1000; Dakopatts, Glostrup, Denmark) and focal positivity for carcinoembryonic antigen (CEA, 1 : 500; Mochida, Tokyo, Japan). Figure 2. The tumor consisted of solid undifferentiated nests and small cords forming tubular structures in a dense fibrocollagenous stroma (original magnification, ×40) Download figure to PowerPoint Figure 3. The tumor located in the upper dermis consisted mainly of solid undifferentiated nests with calcified central necrosis. Small cords forming tubular structures resembling those of syringoma can also be observed (original magnification, ×200) Download figure to PowerPoint The extent of tumor spread was evaluated by computed tomography (CT) and magnetic resonance imaging. The primary tumor had infiltrated the rectus abdominis muscle, and multiple metastases, up to 1 cm in diameter, were observed in the lungs, right bronchus, para-aortic lymph nodes and Th11, right S1, and bilateral ilium. CT scan revealed no continuity between the tumor and the prostate. After consulting a urologist, the possibility of prostate cancer was ruled out. After diagnosis and evaluation of tumor spread, the patient was treated with seven cycles of combination chemotherapy as follows: 5-fluorouracil (350 mg/m2 intravenously) on days 1–5, epirubicin (40 mg/m2 intravenously) on day 1, mitomycin C (3.5 mg/m2 intravenously) on day 1, vincristine sulfate (0.7 mg/m2 intravenously) and carboplatin (300 mg/m2 intravenously) on day 2, every 21–28 days. The treatment was relatively well tolerated without major complications. After seven courses of chemotherapy, evaluation by CT showed no change in the size of the primary lesion, or in the size and number of distant metastases. It is now 6 months since the last course of treatment and the patient appears to have stable disease.