Melorheostosis of the upper limb: a report of two cases.

The etiology, diagnosis, and treatment of two cases of melorheostosis are reported. The hyperostotic lesion corresponded well with both C7 and C8 segments of a sclerotome. The accompanying subcutaneous tumors in case 1 originated from the medical cutaneous nerve of the forearm, whose axons were coming mainly from the C8 dorsal root ganglion. These findings strongly suggest that the primary disorder exists in sensory nerves. Pain originating from the hyperostosis could be suppressed by the disodium salt of (1-hydroxyethylidene) diphosphonic acid.