Disseminated Nocardiosis Masquerading as Soft-Tissue Malignancy: A Case Report

A 59-year-old man, immunosuppressed after renal transplant, presented with a painful posterior thigh mass concerning for malignancy, as well as pulmonary and posterior chest wall nodules. Cultures and mass spectrometry identified Nocardia paucivorans. The patient underwent operative irrigation and debridement of the posterior thigh and chest wall, with 12 months of antibiotic therapy.

A 2-week delay in appropriate treatment was due to low suspicion for infectious etiology. Since cultures generally take weeks for positive diagnosis, advanced molecular or biochemical methods should be used. This case demonstrates importance in maintaining a high index of suspicion for nocardiosis in immunocompromised patients with soft-tissue masses.