A Peculiar Primary Paraganglioma of the Distal Thumb.

A paraganglioma is a highly vascularized neuroendocrine tumor most commonly found within the adrenal gland as a pheochromocytoma. Extra-adrenal paragangliomas are frequently located in the head, neck, thorax, and abdomen. We report the first documented case of a primary paraganglioma found within the appendicular skeleton. Only 2 additional cases of paragangliomas in the extremities have been documented, one in the soft tissue of the forearm and other within the median nerve. Our patient underwent amputation of the distal phalanx, with no sign of recurrence at greater than 1 year of follow-up. Because of the geographic and clinical similarity to a benign enchondroma, radiographic imaging alone may not be sufficient to rule out malignancies inside bones. Thus paraganglioma should remain in the differential and immunohistochemistry is both vital and necessary to confirm the diagnosis. Vigilant and appropriate follow-up is necessary to detect metastases early in these patients.