Hiding in plain sight: a case of chronic disseminated histoplasmosis with central nervous system involvement

Abstract

A 64-year-old man presented with gradual onset of confusion, ataxia and 25-pound weight loss over 3 months. MRI of the brain revealed two enhancing cerebellar lesions suspicious for metastases. Positron emission tomography-CT showed enhancement of cervical and axillary lymph nodes. Left axillary lymph node biopsy showed no evidence of malignancy but instead showed fungal organisms morphologically consistent with Histoplasma spp. Disseminated histoplasmosis with central nervous system involvement was suspected. Further history revealed that the patient had been having subjective fever for the past several months. He has had mild pancytopenia for about 2 years, which had not been further evaluated. Additionally, he had an oesophagogastroduodenoscopy 3 months prior to admission, which had shown granulomatous gastritis. Subsequently, the diagnosis of disseminated histoplasmosis was confirmed by serological testing and bone marrow biopsy. The patient was started on liposomal amphotericin B. Unfortunately, the patient had a catastrophic stroke and was transitioned to comfort care measures.

Clinical, radiological and laboratory characteristics of central nervous system histoplasmosis: A systematic review of a severe disease

“…We found 1159 studies and included 108 manuscripts published between 1962 and 2022, totaling 298 patients 7–10,12–115 . We excluded 38 articles that could not be retrieved.…”

“…Hydrocephalus was typically communicating, although there was one case with an intraventricular lesion 64 . Vasculitis more commonly presented as a small‐vessel disease, 29,33,35,63 particularly in the basal ganglia and brainstem, although cases of large‐vessel disease were also described 46,72 …”

High prevalence and mortality due to Histoplasma capsulatum in the Brazilian Amazon: An autopsy study

“…The majority of these reports show that lungs, spleen, liver and bone marrow are the most frequently affected organs. However, any tissue can be involved, including central nervous system, adrenal glands, gastrointestinal tract and lymph nodes [ 18 – 20 ]. Clinically, histoplasmosis is frequently missed, partly due to the overlap of its symptoms with those of tuberculosis [ 1 ].…”

Clinicopathological characteristics and aetiological factors of granulomatous gastritis

“…[16][17][18][19] Infectious GG causes are infrequent (tuberculosis, aspergillosis, histoplasmosis, parasites, Whipple disease). [20][21][22][23][24] GG has also been associated with neoplasms, vasculitides and foreign material. [25][26][27][28][29][30] When the cause cannot be ascertained, idiopathic GG (IGG) is used and because usually limited to the stomach, often interchangeably with isolated GG.…”

“…The stomach is the most common gastrointestinal (GI) site involved by sarcoidosis, found in only 10% of systemic disease patients, usually asymptomatic and rarely presenting as isolated extrapulmonary involvement 16–19 . Infectious GG causes are infrequent (tuberculosis, aspergillosis, histoplasmosis, parasites, Whipple disease) 20–24 . GG has also been associated with neoplasms, vasculitides and foreign material 25–30 .…”