# A case report of extra-adrenal retroperitoneal myelolipoma

## TL;DR

This paper presents a rare case of a benign tumor outside the adrenal gland, initially misdiagnosed as cancer, and successfully treated with surgery.

## Contribution

The paper adds a new case of extrarenal retroperitoneal myelolipoma to the limited existing literature.

## Key findings

- The tumor was initially misdiagnosed as a well-differentiated retroperitoneal liposarcoma.
- The patient was successfully treated with surgical resection and discharged.
- The case highlights the importance of accurate diagnosis for rare retroperitoneal tumors.

## Abstract

Myelolipoma is a benign tumor composed of mature adipose tissue and hematopoietic elements, typically found in the bone marrow. It mainly occurs in the adrenal gland, with only over 50 cases of extrarenal myelolipoma reported in literature, and extrarenal renal myelolipoma occurring in the posterior abdominal cavity is particularly rare. Currently, there are only 6 reported cases abroad. We report a case of extrarenal retroperitoneal medullary lipoma treated after abdominal pain, which was misdiagnosed as well differentiated retroperitoneal liposarcoma before surgery. The patient was successfully discharged after surgical resection. This paper provides a detailed summary of the clinical presentation, imaging features, diagnosis, and management course of this case, aiming to offer diagnostic and therapeutic insights for clinicians and future research.