Testicular calcifications: Incidence, histology and proposed pathological criteria for testicular microlithiasis

Purpose: Testicular microlithiasis is a clinical syndrome in which men present with innumerable testicular calcifications. Indirect evidence suggests that this syndrome may be associated with an increased risk of germ cell neoplasia. The incidence and types of testicular calcification in normal and diseased testes is unknown. Materials and Methods: A series of 131 orchiectomy specimens were reviewed, including 79 germ cell tumors, and 100 entirely embedded autopsy testes in men with no known testicular pathology. Results: Two types of calcifications were identified. Hematoxylin bodies, consisting of amorphous calcific debris, were present in 6 cases associated with germ cell tumors. In contrast, laminated calcifications were found not only in association with germ cell tumors (35 cases), but also in 2 of 4 cryptorchid testes and 6 of the remaining 145 testes (4%). Of these calcifications 61% were multiple. When laminated calcifications were associated with germ cell tumors there was an increased incidence of extension beyond the tunica albuginea (43 versus 21%) and lymphatic invasion (52 versus 17%, p = 0.046 and 0.012, respectively). Conclusions: Testicular calcifications are heterogeneous. Hematoxylin bodies are specific for germ cell tumors but laminated calcifications, while more common in germ cell tumors, also occur in otherwise normal testes. The pathological criteria for testicular microlithiasis should include the identification of multiple laminated calcifications within seminiferous tubules.