Case of the month January 1999  Diagnosis

Epithelioid hemangioendothelioma (EHE)

This unusual lesion shows many of the characteristic features of this lesion. It affects adults in their 20's and 30's, often in the lower extremity, and has a tendency to occur in multiple bones. The plain radiographs show what has been called a "soap bubble" appearance.  MRI and CT are nonspecific. The pathology shows multiple sometimes anastamosing vascular channels lined with plump endothelial cells.  This lesion is though to be an aggressive benign or low grade malignant tumor with a tendency to recur locally and rarely to metastasize to the lung.  This patient had intralesional currettage only and will be carefully observed on a long term basis for local recurrence and the very rare possibility of metastasis.   Please see a complete discussion of EHE here. 

Of all the bone tumors and tumor-like lesions that occur, only a very few are likely to involve two or more bones.  As a concequence, when you see this rare pattern, you can immediately narrow your differential diagnosis. In these cases two or more adjacent bones, two nonadjacent bones within the same extremity, or more rarely two or more widely separated bones may be involved. Tumors and lesions that may occur in multiple sites include:   Epithelioid hemangioendothelioma,  polyostotic fibrous dysplasia,  enchondromatosis (Ollier's and Mafucci's), multiple hereditary osteocartilagenous exostosis, metabolic disorders (such as gout, Gaucher's disease, or hyperparathyroidism), and infection. In malignant and metastatic tumors that involve two or more bones the lesions are usually presumed to be synchronous metastases, rather than multiple primary occurrences of the tumor. (See more on this with regard to angiosarcoma here.)