Eccrine squamous syringometaplasia. A cutaneous sweat gland reaction in the histologic spectrum of 'chemotherapy-associated eccrine hidradenitis' and 'neutrophilic eccrine hidradenitis'.

A 31-year-old Hispanic man presented in the pancytopenic phase of acute myelocytic leukemia and was treated with the chemotherapeutic agents mitoxantrone and cytarabine. After 5 days, an erythematous, blanching, papular, crusted eruption developed on his forehead, chest, and legs. Some lesions showed confluence and all were at the same developmental stage. Clinical diagnoses included necrotizing vasculitis and sepsis. A biopsy specimen revealed widespread noninflammatory syringometaplasia of eccrine ducts. Well-developed intercellular bridges and eosinophilic cytoplasm were seen within the metaplastic cells; apoptoses and occasional mitoses were present. This process is distinct and probably occurred secondary to direct toxic injury from the chemotherapeutic drugs. Because similar changes have occurred in patients with neutrophilic eccrine hidradenitis, we believe our patient represents an example of the noninflammatory end of the spectrum of chemotherapeutic eccrine gland reactions.