Locally metastasizing vascular tumor
Spindle cell, epithelioid, or unclassified hemangioendothelioma?. The authors report the case of a 2-year-old boy with a recurrent and locally metastasizing, spindle cell, vascular tumor with histiocytoid cells involving the skin, subcutaneous tissue, and muscle of the right forearm, the right distal radius and ulna, and multiple lymph nodes of the right axilla. Diagnoses of hemangioma, hemangiopericytoma, angiomatosis, spindle cell hemangioendothelioma, and malignant hemangioendothelioma were made on successive excision specimens. The soft tissue of the right arm became diffusely enlarged, and a severe syndrome developed that was similar to that described by Kasabach and Merritt. The limb was amputated above the elbow, the axillary lymph nodes were cleared, and a total dose of 6,000 centigrays axillary radiation was given. After operation, the Kasabach-Merritt syndrome resolved. Despite the lymph node metastases and multiple tissues involved, the patient has remained well 6 years after surgery. Although the tumor exhibited some of the histologic features of a spindle cell hemangioendothelioma, the low-grade aggressive behavior resembled that of an epithelioid hemangioendothelioma. The reported case cannot be classified into any of the recognized categories or subdivisions of vascular tumors.