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

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. 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. An oligosymptomatic femoral neck fracture, not requiring medical intervention is considered a rare complication of bone cancer.