Scalp actinomycosis mimicking a soft-tissue sarcoma in a 17-year-old female: A case report

ABSTRACT Actinomycosis is a rare chronic granulomatous and suppurative bacterial infection caused by Actinomyces spp . The disease is usually due to the introduction of the bacteria into the wound following trauma. Scalp involvement by actinomycosis is rare causing diagnostic dilemma. We report a case of actinomycosis occurring in the scalp posing diagnostic challenges. A 17-year-old female presented with recurrent frontotemporal scalp mass of 7-month duration with a history of trauma to the head in the past. Computed tomographic scan showed left parietal soft-tissue thickening with no bone or brain involvement. Wide local excision was done and tissue submitted for histology confirmed actinomycosis with special stains additionally highlighting bacterial filaments. Actinomycosis can virtually affect any site in the body, but its occurrence in the scalp is a rare entity posing diagnostic dilemma to the surgeon. Histopathological examination remains the cornerstone to a definitive diagnosis.