# Rare abdominal wall clear cell carcinoma in endometriosis: case report and literature review of diagnostic and therapeutic considerations

## TL;DR

A rare case of clear cell carcinoma arising from endometriosis in the abdominal wall is reported, highlighting the need for accurate diagnosis and complex reconstruction.

## Contribution

This case report adds to the limited literature on malignant transformation of endometriosis into clear cell carcinoma.

## Key findings

- Clear cell carcinoma arising from endometriosis is rare and highly aggressive with high recurrence and metastasis rates.
- Radical resection and two-layer mesh reconstruction are crucial for optimal oncological and functional outcomes.
- Accurate diagnosis is essential due to the diagnostic challenges presented by this condition.

## Abstract

Endometriosis of the abdominal wall is exceptionally rare, with malignant transformation to clear cell carcinoma being of even greater rarity. In this paper, the importance of accurate diagnosis and appropriate treatment is emphasized, including the possibility of mesh reconstruction of the abdominal wall.

A 53-year-old woman presented with a rapidly enlarging abdominal wall tumor, 19 years after undergoing a caesarean section. Prior to her referral to our facility, a peripheral hospital had already performed tumor resection with mesh-based abdominal wall reconstruction. Tumor histology had revealed endosalpingiosis without evidence of malignancy. However, a year later, the patient exhibited a relapse accompanied by renewed rapid growth. Both punch and open biopsies revealed endosalpingiosis. Due to its rapid growth, a total resection of the tumor was performed. This necessitated the removal of a significant portion of the abdominal wall musculature and fascia. The abdominal wall was then reconstructed using a two-layer mesh. Final histological examination revealed a clear cell carcinoma that had arisen from endometriosis. Following the complete healing, the patient received adjuvant platinum-based chemotherapy and radiation to the inguinal area.

Clear cell carcinoma of the abdominal wall arising from endometriosis is a rare and highly aggressive form of malignant transformation with a high rate of recurrence and metastasis. In rapidly growing abdominal wall tumors following gynaecological surgery, the objective should be radical resection. In addition to this, the selection of appropriate reconstruction procedures is crucial to achieving optimal oncological and functional results. Examples of such reconstruction procedures include a two-layer mesh reconstruction.

This case aims to raise awareness of this rare and highly aggressive malignancy and to discuss diagnostic challenges and therapeutic strategies, including complex abdominal wall reconstruction.