Hidden in Plain Sight: Nocardia farcinica Posterior Shoulder Abscess Temporally Associated With Sports Massage in an Immunocompetent Host.

Nocardia farcinica is an uncommon but clinically significant pathogen characterized by enhanced intrinsic antimicrobial resistance and a recognized propensity for hematogenous dissemination. Musculoskeletal nocardiosis is rare and most commonly affects immunocompromised individuals following hematogenous spread from a pulmonary source. We report a male patient with a prior history of curative esophagectomy for esophageal carcinoma who presented with a four-week history of progressive right posterior shoulder pain, systemic features of infection, and markedly elevated inflammatory markers following a vigorous sports massage, without documented immunosuppression, skin breach, or identifiable traumatic inoculation event. Magnetic resonance imaging demonstrated a complex fluid collection measuring approximately 53 × 55 × 45 mm centered within the right teres major region with extensive periscapular soft-tissue edema. Two sequential surgical drainage procedures were performed, collectively yielding substantial purulent material without evidence of glenohumeral joint involvement or osteomyelitis. Microbiological culture identified heavy growth of N. farcinica, necessitating cessation of empirical intravenous flucloxacillin and initiation of linezolid, followed by a planned six-month course of oral co-trimoxazole. Cross-sectional imaging excluded disseminated disease. The patient achieved satisfactory clinical improvement with preserved neurovascular function at follow-up. This case represents a potentially novel mechanism of nocardial inoculation via vigorous deep soft-tissue massage and underscores the importance of considering atypical pathogens in deep soft-tissue infections that follow an unexpected or treatment-refractory clinical course.