Tenosynovitis with psammomatous calcification: a poorly recognized pseudotumor related to repetitive tendinous injury

Tenosynovitis with psammomatous calcification, described in 1983 by Gravanis and Gaffney, is a distinctive clinicopathologic variant of "idiopathic calcifying tenosynovitis" or "calcific tendonitis." However, tenosynovitis with psammomatous calcification is poorly recognized by pathologists and for this reason has not been adopted widely as a distinct entity. We present the clinicopathologic features of 6 cases of tenosynovitis with psammomatous calcification. Cases involved the tendons, peritendinous soft tissues, and adjacent synovium of the distal extremities (3 fingers, 2 feet, and 1 carpal tendon) of women who ranged in age from 16 to 83 years (mean 48 y). The lesions presented a painful mass. A history of occupational or sports-related repetitive motion and/or persistent mild trauma was noted in all patients. No patient had a history of hyperphosphatemia. All lesions were treated by surgical excision and described clinically as variably cystic nodules composed of amorphous "cheese-like" debris. Histologically, the lesions were centered in the tendon or peritendinous soft tissue and composed of a mixed (myo) fibroblastic and histiocytic proliferation in association with a degenerating tendinous tissue, which was undergoing dystrophic calcification, with the formation of distinctive psammoma body-like spheroidal bodies. The clinical and morphologic characteristics of tenosynovitis with psammomatous calcification (distal location, absent hyperphosphatemia, and psammomatous calcifications) differ from those of typical idiopathic calcifying tenosynovitis/calcific tendinitis (proximal location and dystrophic tendinous calcification) and tumoral calcinosis (hyperphosphatemia and amorphous soft tissue calcification), and it should be recognized as a distinct clinicopathologic entity. Improved recognition of these unique features by pathologists should allow ready diagnosis of this unusual pseudotumor in most instances.