A rare case of Adrenal histoplasmosis presenting as adrenal insufficiency and hypogonadism following a visit to bat caves.

Gideon Mlawa, Mahesh Deore, Saiji Nageshwaran,

St Georges Hospital, Darrent Valley Hospital.

Background:  Histoplasmosis is an opportunistic fungal infection that commonly affects immunocompromised individuals. Histoplasmosis  may be asymptomatic  or  may present with progressive systemic manifestations (pulmonary or disseminated).

We present a case of a 76 year old immunocompetent man presented to hospital with 8 weeks history of general malaise and lethargy, intermittent night sweats, a productive cough, weight loss of 2.5 stones in two months and low grade fever. He had completed two courses of antibiotics prescribed by his general practitioner, with no resolution of his symptoms. He reported no history of tuberculosis contacts. Significant history was of travel to Malaysia and a visit to bat caves two years prior to the onset of  symptoms  On admission, he was haemodynamically stable and his initial blood tests were normal apart from raised CRP of 80mg/L. Chest XRay was normal.CT of  sinuses showed minimal mucosal thickening                                                                                                                               CT chest, abdomen and pelvis revealed large bilateral adrenal heterogeneous masses measuring 6.1cmx4.5cmx3.7cm on the right, and 6.4cmx6.2cmx4.3cm on the left.  Adrenal biopsy showed fungal spores on microscopy. 

He was started on antifungal therapy for likely adrenal histoplasmosis and discharged home.

He was readmitted 2 months later with a GCS of 6/15, Temperature 38șC, and hypotensive episodes.  He had normal CT and MRI brain results, negative blood cultures and unremarkable CSF studies. Echocardiogram excluded the vegetations., He was treated with intravenous empirical antibiotics and  hydrocortisone. He was  continued on his antifungal therapy.

Initial short synacthen test showed normal response, however he  became more tired and hyperpigmented with a subsequent short synacthen test showing a suboptimal response T0-=333nmol/L, T 30=378nmol/L. He also  developed primary  hypogonadism subsequently, thought to be due to effect of antifungals or due to histoplasmosis itself.

Conclusion- Adrenal histoplasmosis is rare, especially in  immunocompetent individuals and  should be considered as a differential diagnosis in any  patient presenting with bilateral adrenal masses, constitutional symptoms and suggestive history. Also one should be vigilant about possible side effects of antifungals eg hypogonadism in this case.