Co-Existing Ectopic Cortisol-Producing Adenoma and Retroperitoneal Schwannoma, a Rare Case Report

Abstract

Background: Ectopic cortisol-producing adrenocortical adenoma (ECPA) is extremely rare, with only a few cases reported. Retroperitoneal schwannoma is also uncommon, accounting for only 0.7-5% of all schwannomas. It is peculiar to have both conditions at the same time, and it is intriguing to explore their possible connection. Herein, we present a case of both ECPA and retroperitoneal schwannoma and provide our conjectures regarding their co-occurrence.

Case presentation: A 38-year-old female presented with a two-year history of facial and lower limb edema, as well as chest tightness and palpitations for the past four months. Physical examination revealed hypertension, a high body mass index (BMI), moon face, thick neck and back fat, abdominal obesity, and purple striae on the abdomen. Laboratory tests indicated an persistent increased cortisol level and suppression of adrenocorticotropic hormone (ACTH). Adrenal-enhanced computed tomography (CT) scan showed that both adrenal glands appeared normal without evident adenomas or hyperplasia. However, the scan revealed two lesions located in the right renal hilum and retroperitoneal area positioned anteriorly to the lower margin of the lumbar 2 pyramid. Further imaging using ⁶⁸Ga-DOTATATE PET/CT revealed concentrated radiotracer uptake in the tumor at the right renal hilum, indicating it may be responsible for the patient's Cushing's symptoms. After laparoscopic resection of these masses, clinical symptoms improved significantly. Postoperative pathology confirmed the right renal hilum one lesion as an ECPA while identifying another lesion as a schwannoma.

Conclusion: Our literature reported a case with the diagnosis of both ECPA in the right renal hilum and retroperitoneal schwannoma. ⁶⁸Ga-DOTATATE PET/CT imaging can provide functional and locational information on tumors, enabling a comprehensive examination of the entire body to identify lesions that require appropriate treatment.

Keywords: Cushing syndrome; case report; cortisol-producing adrenocortical adenomas; ectopic adrenocortical adenoma; schwannoma.

Figure 1

Radiological images of the patient. (A and B) The computed tomography (CT) images depict tumors in the right renal hilum (A) and retroperitoneal area (B). (C and D) Positron emission tomography (PET)-CT with 68 Ga-DOTATATE images of the right renal hilum (C) and retroperitoneal area (D). The red arrows indicate the tumors, and the red cross indicates the agent concentration in the tumor.

Figure 2

Tumors morphology and pathological images. (A and B) The appearance and incision of both tumors. The smaller yellow one (left) from patient's retroperitoneal area, and the larger brown one (right) from patient's right renal hilum. (C and D) The retroperitoneal tumor (schwannoma) is shown through H&E staining (C) and AC100 immunohistochemical staining (D). (E and F) The renal hilum tumor (ectopic adrenocortical adenoma) is displayed through H&E staining (E) and inhibin immunohistochemical staining (F).