Bone marrow Emergomyces and Mycobacterium tuberculosis in the setting of advanced human immunodeficiency virus

A 44‐year‐old man with advanced, untreated human immunodeficiency virus (HIV) (diagnosed 8 years prior) presented with a 2‐week history of constitutional symptoms, gastrointestinal upset (vomiting and intermittent diarrhoea, without haematemesis or melena), dyspnoea, pleuritic chest pain and intermittent haemoptysis. On examination, he appeared cachectic, pyrexial and hypoxic, with a pulse rate of 141, hypotension (blood pressure [BP] 93/67), a hyperpigmented papular rash, stomatitis and oropharyngeal candidiasis. He showed acute respiratory distress with widespread bilateral crepitations, a pericardial rub and hepatosplenomegaly without signs of cardiac failure. Imaging revealed bilateral hilar lymphadenopathy, lung infiltrates with ground‐glass opacity, intra‐abdominal lymphadenopathy, hepatosplenomegaly and a small pericardial effusion (1 cm) on ultrasound. Laboratory tests revealed severe immunosuppression (CD4 count, 1 × 10⁶ cell/L); significant liver dysfunction; renal impairment; and marked hyperferritineamia, 110 757 μg/L. The full blood count noted a white cell count, 7.83 × 10⁹/L; haemoglobin, 53 g/L; and platelet count, 33 × 10⁹/L. The blood film showed occasional teardrop red blood cells, leucoerythroblastic changes and scanty neutrophils with critical blue–green neutrophilic inclusions (arrowhead, upper left panel) and/or small, unencapsulated organisms resembling yeasts (arrow, upper left panel). Similarly, neutrophils and histiocytes displayed engulfed, spindle‐shaped yeasts on bone marrow (BM) aspirate and trephine biopsy (upper middle panel). Haemopoiesis was hypercellular and disorganised, with numerous fungi‐ and debris‐laden histiocytes, but no granulomas. Periodic acid–Schiff (upper right panel), Grocott (lower left panel) and Gomori methenamine silver (lower middle panel) stains highlighted clustered yeasts. The Ziehl–Neelsen stain was positive for scanty acid‐fast bacilli (arrow, lower right panel). Culture of the BM confirmed dual infection with Emergomyces, presumably E. africanus and Mycobacterium tuberculosis. Unfortunately, Emergomyces speciation was not performed. The patient demised soon after admission.

Emergomycosis is a fungal infection primarily affecting severely immunocompromised individuals and particularly those with advanced HIV/acquired immune deficiency syndrome. It typically presents with cutaneous or pulmonary involvement, but severe cases may have disseminated infection involving the liver, spleen and BM. A recent systematic review of 77 proven cases of Emergomyces describes an all‐cause mortality of 42.9%, positive BM histology in 3.9% of cases and diagnosis by BM aspirate culture in 18.2%. ¹

This patient demonstrated disseminated emergomycosis, which likely involved multiple organs besides the BM and peripheral blood. The blue–green neutrophilic inclusions on blood film were consistent with critical illness. Of note, patients with severe immunocompromise may not mount a granulomatous response to opportunistic infection, as demonstrated in this case. ²