Introduction:
Histoplasmosis, an opportunistic infection, is caused by histoplasma capsulatum, a dimorphic fungus. Necrotizing granulomatous lymphadenitis is a common cause of tubercular lymphadenitis in our country, but can also be found in parasitic and fungal infections also. Histoplasmosis is often misdiagnosed as tuberculosis in endemic regions leading to high mortality. As a result of the potentially fatal nature of the disease, careful evaluation with tissue diagnosis is recommended. Here, we present a case of Histoplasmosis which was misdiagnosed and treated as tuberculosis from outside.
Methods:
This is a case report from a single center.
Results:
A middle age man who had undergone ABO-compatible renal transplant one year back, donor being his wife, induction agent during transplant-ATG, presently on tab Wysolone, cap Tacrolimus and MMF presented with a history of intermittent fever for last 1 month with weight loss. He had visited a local hospital where he was found to have cervical lymphadenopathy and FNAC of lymph node revealed granuloma with necrosis. He was subsequently started on Anti-Tubercular drugs and discharged.
However, even after starting ATT, the fever persisted and over next few days, the frequency and intensity increased and he presented to us with pain in right upper abdomen.On investigation,there was allograft dysfunction and hypercalcemia.
Subsequently, CT scan of abdomen was done for pain abdomen which revealed perihepatic abscess and pus was sent for microscopy and culture. Reports revealed gene expert and AFB negative, gram stain negative, however fungal stains with PAS was positive and histoplasma was detected.
Morover, biopsy of lymph node was done which showed poorly formed granulomas composed of macrophages, multinucleated giant cells with focal necrosis, intracellular and extracellular yeast like fungal bodies, and on further evaluation, Intracellular and extracellular PAS positive histoplasma were detected. Stain for AFB was negative. Thus, the diagnosis of histoplasmosis was made.
The patient was subsequently started on liposomal amphotericin B followed by Tab Itraconazole and pus was drained by inserting a pig tail catheter. The patient gradually responded to treatment and was subsequently discharged.
Conclusions:
The diagnosis of histoplasmosis should be considered in the differential diagnosis of granulomatous lymphadenitis. Histoplasmosis is often misdiagnosed as tuberculosis in endemic regions leading to high mortality. A high index of suspicion should be kept to diagnose rare fungal infections like histoplasma and differentiate them from tuberculosis in post transplant since treatment differs in both cases, which will ultimately help to reduce morbidity and mortality.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.