Eruptive epithelioid hemangioendothelioma with spindle cells
A 39-year-old white man presented with four discrete dermal nodules in his right upper arm. Biopsy revealed superficial dermal well-circumscribed nodules composed of solid areas and vascular spaces lined by epithelioid endothelial cells and a similar nodule composed of spindle and epithelioid cells. A moderate mitotic count of 3-4 mitoses/10 hpf was present. Multiple lesions erupted 1 month later distally and proximally to the original lesions. Magnetic resonance imaging of the right arm demonstrated a lesion in the humerus. Biopsy of the humerus showed a vascular tumor with similar histologic features to the overlying skin lesions. The differential diagnosis included epithelioid vascular tumors, bacillary angiomatosis, pyogenic granuloma, and Kaposi sarcoma. Vascular lesions containing epithelioid and spindle cells span a spectrum from benign to malignant. We believe these tumors belong in the category of hemangioendothelioma and propose the name eruptive epithelioid hemangioendothelioma with spindle cells. Our case emphasizes that eruptive cutaneous vascular lesions do not always suggest immunosuppression or malignancy. Additionally, it highlights the association between epithelioid vascular lesions of the skin and bone.