Adrenal tuberculosis after a pheochromocytoma: a misleading tumoral presentation

Adrenal gland involvement could account for 6% of active tuberculosis. The diagnosis of this extrapulmonary form of tuberculosis is difficult, especially when presenting as unilateral adrenal tumor. This report describes an unusual case of adrenal tuberculosis presenting as a tumor occurring shortly after surgical removal of an adrenal pheochromocytoma located in the opposite gland, in a 63-year-old woman with a previous history of breast cancer. At initial presentation, the patient suffered from symptomatic paroxysmal hypertension. A pheochromocytoma in the left adrenal was diagnosed and resected. One year later, while physical examination and biological parameters were unremarkable, an enhanced adrenal computed tomography (CT) scan showed a right adrenal mass mimicking the CT features of the resected pheochromocytoma. A peripheral tissular rim delineating a central hypodensity characterized this tumor. Magnetic resonance imaging (MRI) showed the same findings on gadolinium-enhanced T1-weighted slices, while the mass was not seen on T2-weighted images. No tumoral signal loss was observed on out of phase images when using the in phase-out of phase T1-weighted sequence. Because of the tumoral evolution and the uncertainty of the nature of that lesion, the patient underwent a second adrenalectomy. Definitive diagnosis was provided by culture of tissue sample, which resulted in the identification of Mycobacterium tuberculosis. In an era of tuberculosis resurgence, this unusual case underscores the necessity of keeping in mind adrenal tuberculosis as a possible differential diagnosis in adrenal tumors of uncertainty nature. It stresses the importance of culture of biopsy tumor, whenever feasible, to avoid unnecessary operations. In the near future, interferon-gamma assay could be a valuable means to recognize extrapulmonary forms of tuberculosis.