The chicken and the egg dilemma: A case of disseminated MAC with Hodgkin's lymphoma

INTRODUCTION: Mycobacterium avium complex (MAC) as a cause of disseminated disease has been well described in immunocompromised hosts. We report a case of disseminated MAC diagnosed in an otherwise healthy patient, one year before further testing and follow-up revealed a diagnosis of Hodgkin's lymphoma. CASE PRESENTATION: A 48-year-old woman with no significant medical history presented with new-onset fever, chills and night sweats. Chest imaging revealed large conglomerate mediastinal lymph nodes (LN). Endobronchial ultrasound-guided biopsy demonstrated caseating granulomatous inflammation and MAC on broth culture. She was started on guideline-based antibiotic therapy for disseminated MAC but showed no improvement after 6 months. An open mediastinal biopsy confirmed the findings of non-caseating granuloma. However, due to continued symptoms and widespread lymphadenopathy on additional full body imaging, an iliac lymph node core biopsy was performed which revealed abnormal CD30(+) lymphoid infiltrate consistent with Hodgkin's lymphoma (HL). She was started on steroids and chemotherapy, whilst maintained on MAC treatment. DISCUSSION: Disseminated MAC is largely limited to immunocompromised hosts, signs and symptoms of which may overlap with lymphoma. Our case demonstrated that multiple initial LN biopsies were unrevealing except for MAC. As no clinical improvement was observed with guideline based MAC treatment, further diagnostic measures were aggressively pursued ultimately leading to a diagnosis of HL. It is unclear whether disseminated MAC preceded lymphoma, an early undiagnosed lymphoma led to MAC infection or an undefined systemic immune disorder was causative for both these processes.