# Adrenal Myelolipoma Inside an Adrenal Cortical Adenoma

## TL;DR

A rare case of adrenal myelolipoma found inside a non-functioning adrenal cortical adenoma is reported, highlighting unique histopathological features at their interface.

## Contribution

This is the first report describing the interface features between adrenal myelolipoma and adrenal cortical adenoma.

## Key findings

- The myelolipoma was found to contain adrenal cortical adenoma cells within its borders.
- Trilineage hematopoiesis was observed near the interface of the two lesions.
- The adrenal cortical adenoma may have influenced the development of the myelolipoma.

## Abstract

A case of an incidental adrenal myelolipoma inside a non-functioning adrenal cortical adenoma is reported. A 65-year-old woman with a history of right-sided clear cell renal cell carcinoma presented for a follow-up of a left-sided adrenal mass first noted incidentally on a previous renal cell carcinoma workup. Macroscopically, it was a well-circumscribed, tan-yellow mass with gritty hemorrhage. Histopathologic evaluation showed the proliferation of clear to eosinophilic cells, filled with small vacuoles with a well-delineated lesion composed of mature adipose tissue and bone marrow elements. Also, this focus of myelolipoma revealed adenoma cells inside its borders; and interestingly, trilineage hematopoiesis was mostly observed near the adenoma-myelolipoma interfaces. To our knowledge, this is a unique report mentioning some additional features about the interfaces of these lesions. It can be suggested that the presence of adrenal cortical adenoma played the main stressor role in giving rise to myelolipoma and myelolipoma, being closer to the adenoma's vascular network, caused the different interface features.