Management of Metastatic Apocrine Hidradenocarcinoma with Chemotherapy and Radiation.

Hidradenocarcinoma is a rare aggressive form of cutaneous adnexal skin carcinoma originating from the sweat gland. Due to its low incidence, prognostic and treatment strategies are still being explored both for primary and advanced disease. This tumor most often presents as either solid or cystic appearing subcutaneous nodules, which may be associated with pruritus or ulceration. To date the mainstay of treatment for local disease has been surgical excision; however, the paucity of historical data available has shown that these tumors often behave aggressively with high rates of local recurrence, metastasis, and poor overall outcomes. There are few case reports describing the utility of radiation therapy in the treatment of hidradenocarcinoma. Herein, we present a case of metastatic apocrine hidradenocarcinoma in a 32-year-old Caucasian male. The patient initially underwent excisional biopsy which confirmed the diagnosis of poorly differentiated, highly infiltrative, apocrine hidradenocarcinoma. He received systemic chemotherapy for metastatic disease, followed by radiation therapy to areas of grossly palpable adenopathy. Prior to radiation therapy the patient had an enlarged hypermetabolic conglomerate of lymph nodes in the right axilla, and borderline enlarged low activity nodes within the left axilla. He received 3 cycles of chemotherapy followed by tamoxifen and radiation therapy (50.4 Gy in 28 fractions) to areas of progressive disease in the bilateral axilla, lower neck, and axillary skin. Following treatment, the patient had complete resolution of skin nodules and improvement of his pruritus. While the role of radiation therapy in the treatment of hidradenocarcinoma has not been well established, this case report demonstrated the potential benefit of external beam radiotherapy in the management of this rare disease.