Case report of a bilateral adrenal myelolipoma associated with Cushing disease

Abstract

Rationale: Adrenal myelolipomas are rare benign tumors, composed of a variable mixture of mature adipose tissue and hematopoietic tissue. These tumors are frequently detected incidentally and are usually asymptomatic, and hormonally inactive.

Patient concerns: During a routine health checkup, a 52-year-old man was found to have a tumor on the bilateral adrenal glands. Abdominal computed tomography revealed a well-defined, heterogeneously enhanced bilateral adrenal mass, suggesting a myelolipoma.

Diagnoses: The hormonal evaluation revealed adrenocorticotropic hormone (ACTH) dependent Cushing syndrome.

Interventions: The patient underwent left adrenalectomy, and transsphenoidal resection of a pituitary mass. The final diagnosis was adrenal myelolipoma associated with Cushing disease.

Outcomes: Growth of right adrenal myelolipoma was detected during the 7-year follow-up. There were enhancing pituitary lesions in repeat magnetic resonance imaging of the sellar region, which implies persistent or recurrent pituitary adenoma. This case reinforces relationship between Cushing disease and adrenal myelolipoma.

Lessons: To the best of our knowledge, this is the first reported pathologically confirmed bilateral adrenal myelolipoma associated with Cushing disease. This report supports the idea that ACTH is associated with the development of adrenal myelolipoma.

Figure 1

A, Abdomen and pelvic CT (C E) scan finding shows heterogenous fatty masses at both adrenal gland areas. B, Abdomen dynamic MRI (C E) scan finding shows 8.7 × 8.0 × 9.2 cm left adrenal mass and 3.4 × 3.0 × 3.5 cm right adrenal mass containing large amount of fat.

Figure 2

A, Microscopic findings of the left adrenal tumor. The tumor is separated from the hyperplastic adrenal cortex (upper) by thin fibrous capsule. B, The tumor consists of mature adipose cells interspersed with some scattered areas of hemaotopietic cells, which is similar to those that form the normal bone marrow (A: H-E ×100 and B: H-E × 200).

Figure 3

Microscopic findings of the pituitary gland biopsy. A, Pituitary gland biopsy demonstrated proliferation of round to polygonal cells. B, This lesion showed the disruption of reticulin network. C, Tumor cells are strongly positive for ACTH (A: H-E × 400, B: Reticulin stain × 400; C, Immunohistochemical stain for ACTH) × 400).