Background: Malignant nodular hidradenoma (MNH) is an infrequent, highly malignant, primary skin tumour derived from eccrine sweat glands. Most tumours occur in elderly individuals. MNH has very poor prognosis, high recurrence and a high rate of metastases. The best method of treatment is still unclear: radical surgical excision is widely used, and selective lymph node dissection is also suggested. The value of the adjuvant radiotherapy and chemotherapy has not been confirmed.
Patients and treatment: Seven MNH patients (4 men, 3 women, age 60-87 years) were treated between 1991 and 2007 in the Dermatology Unit of San Donato Hospital of Arezzo and in the Section of Dermatology of University of Siena, Italy. Tumours varied from 0.8 to 4.4 cm in size. All patients underwent local excision; five also had lymph node dissection. One patient underwent adjuvant radiotherapy, and three received chemotherapy.
Results: Six of seven patients died, with survival varying from 15 to 45 months. Distant metastases occurred in two patients. Survival time was inversely proportional to the size of the tumour.
Conclusions: MNH is an aggressive tumour and should be diagnosed and excised as early as possible. Histological parameters are paramount, but correct diagnosis also calls for attention to clinical presentation and any history of recurrence or recent enlargement of long-standing lesions. In our experience, radiotherapy and chemotherapy do not seem to prolong survival.