Primary adrenal tuberculosis infection in patients with Behcet's disease presenting as isolated adrenal metastasis by 18F-FDG PET/CT: a rare case report and literature review

Abstract

Primary adrenal tuberculosis (TB) is a rare type of extrapulmonary tuberculosis (EPTB). A pathological biopsy is usually required to make a definite diagnosis due to nonspecific symptoms. Antituberculous chemotherapy is the main treatment regimen, and cortisol replacement therapy should be added when adrenal insufficiency is involved. Here, we present a 59-year-old man who had recurrence of oral and genital aphthosis for 3 years and was diagnosed with Behcet's disease (BD), which was cured by thalidomide. After 10 days of admission, the patient had sudden abdominal pain in the right upper quadrant with high fever and was diagnosed with acute cholecystitis attack, which was treated by percutaneous transhepatic gallbladder drainage (PTGBD). Further contrast-enhanced CT showed a right adrenal mass with a diameter of 2.0 cm, and PET-CT indicated intense ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake in the right adrenal mass with a maximum standardized uptake value (SUV_max) of 15.2. As a metastatic adrenal mass was suspected, the patient underwent retroperitoneal laparoscopic adrenalectomy. Histopathological and immunohistochemical analysis revealed primary adrenal TB. After routine anti-tuberculosis treatment with isoniazid, rifampin, pyrazinamide and ethambutol for six months, the patient was cured and discharged. In summary, primary unilateral adrenal TB without adrenal insufficiency is difficult to diagnose only on the basis of clinical manifestations and examinations. Further studies are needed to develop an easier and more accurate diagnostic examination.

Keywords: Behcet’s disease; PET/CT; Primary adrenal tuberculosis; adrenal metastatic mass; case report.

Figure 1

The dynamic changes in adrenal CT images of the patient in our case during hospitalization. (A) Adrenal CT on the first day after admission revealed a right adrenal mass with a size of 2.0 cm ×2.0 cm ×0.9 cm. (B) Adrenal contrast-enhanced CT on the fifth day after admission showed a right adrenal mass with a size of 2.0 cm ×2.1 cm ×0.9 cm that exhibited peripheral rim enhancement. (C) Adrenal CT revealed that the size of the adrenal mass increased to 2.5 cm ×2.3 cm ×1.0 cm on the 17th day after admission. (D) Adrenal contrast-enhanced CT showed an adrenal mass with an increased size of 3.1 cm ×2.5 cm ×1.5 cm on the 24th day after admission. The adrenal mass is indicated by a thick arrow.

Figure 2

¹⁸F-FDG PET/CT of the patient in our case. (A) Maximum intensity projection (MIP) images revealing intensely avid foci in the right suprarenal region (thick arrow) and foci of intense uptake in the spleen (dashed arrows) and retroperitoneal regions (curved arrows). (B-E) CT images showed intense FDG uptake in the right adrenal mass (2.3 cm ×1.8 cm ×1.0 cm) (thick arrow), retroperitoneal lymph nodes (≤2.5 cm ×1.2 cm) (curved arrows) and spleen (0.8 cm ×0.5 cm) (dashed arrows).

Figure 3

Reconstructed three-dimensional images. (A) The right adrenal mass (thick arrow) with a size of 3.1 cm ×2.5 cm ×1.5 cm. (B) The enlarged retroperitoneal lymph nodes were close to the abdominal aorta and inferior vena cava.