# Subcapital Femoral Neck Fracture in a Professionally Active Patient Undergoing Palliative Treatment for Endothelial Cell-Derived Epithelioid Haemangioendothelioma (EHE)

## TL;DR

A 44-year-old patient with a rare bone cancer experienced a rare subcapital femoral neck fracture that did not require surgery.

## Contribution

This case highlights the rare occurrence of a non-traumatic femoral neck fracture in a patient with epithelioid haemangioendothelioma.

## Key findings

- The patient had a subcapital femoral neck fracture detected via CT scan in 2023.
- The fracture was stable and did not require surgical intervention due to pelvic changes.
- The patient remained professionally active despite ongoing cancer treatment.

## Abstract

Background and Clinical Significance: Femoral neck fracture frequently occurs in the elderly population but may also present in patients diagnosed with primary cancer or bone metastases. A pathological, oligosymptomatic fracture associated with epithelioid haemangioendothelioma (EHE), a rare endothelial cell-derived sarcoma, is uncommon. Case Presentation: A 44-year-old patient underwent biopsy procedures three times (2010, 2012, 2013) for a focal lesion of the left ischium, none confirming its malignant nature. The last biopsy revealed a neoplastic tissue with features of discrete dysplasia. The lesion did not undergo medical follow-up for seven consecutive years. In August 2020, the patient presented with right lower limb pain. A CT scan, PET/CT scan, and biopsy confirmed EHE with spindle/sarcomatous features. In November 2020, chemotherapy (5xADIC) started (PET/CT confirmed a partial response). After its completion in July 2021, bone progression occurred and sirolimus-based therapy was started. After 3 months, a small liver metastasis was visualized on PET/CT, which did not result in the termination of treatment. In December 2021, pamidronate-based antiresorptive therapy was started. Liver metastasis remained stable in follow-up CT scans. Due to pelvic and spinal lesions, the patient was assisted by elbow crutches and underwent radiotherapy, remaining professionally active. The patient did not report any trauma, but in August 2023, a subsequent CT scan revealed a subcapital fracture of the left femoral neck in the fusion phase. Due to pelvic changes and the stable nature of the fracture, surgical treatment was abandoned. Conclusions: An oligosymptomatic femoral neck fracture, not requiring medical intervention is considered a rare complication of bone cancer.