Primary actinomycosis of the foot in a patient with neurofibromatosis: a case report.

Actinomycosis is a chronic and suppurative infection caused by an endogenous gram-positive bacterium. The usual sites of infection are the head and neck, thorax, and abdomen and are almost always endogenous in origin. Primary actinomycosis is rare and is usually associated with external trauma. The authors report a case of a primary actinomycosis presented as a mass on the foot that mimics neurofibroma in a 56-year-old Asian woman with neurofibromatosis. The patient has no history of preceding trauma. She was treated with excisional biopsy. Histopathology of the excised mass showed features of actinomycosis. Culture for bacteria, fungus, and acid-fast bacilli were all negative. The patient recovered well and there is no recurrence after a 25-month follow-up period.