Cutaneous disseminated actinomycosis in a patient with acute lymphocytic leukemia

Actinomycosis is an uncommon infectious disease caused predominantly by Actinomyces israelii. The cutaneous disseminated form is usually caused by hematogenous dissemination from a primary extra-cutaneous lesion. We report here cutaneous disseminated actinomycosis without any detectable extra-cutaneous lesions in a 42-year-old Japanese woman with acute lymphocytic leukemia. Multiple soft nodules developed on her upper and lower extremities. Histopathological examination revealed "sulfur granules", which are a specific finding for actinomycosis. Cultures from biopsy specimens were not successful. There were no cervicofacial, thoracic, nor abdominal lesions. These findings suggest that cutaneous disseminated actinomycosis in our patient developed primarily in the skin. Although the patient was immunocompromised, antibiotic treatment with minocycline was effective.