Microinvasive germ cell neoplasia of the testis.

BACKGROUND

The term microinvasive germ cell neoplasia denotes the presence of neoplastic germ cells in the tubuli and interstitium of the testis, unaccompanied by clinically detectable tumor.

METHODS

Testicular biopsy specimens from three patients (age range, 26-38 years) without clinical evidence of tumor showed microinvasive germ cell neoplasia. The indications for biopsy were gynecomastia and testicular atrophy in Patient 1, infertility in Patient 2, and nonseminomatous cancer in the contralateral testicle in Patient 3.

RESULTS

In all three cases, orchiectomy specimens disclosed multifocal intratubular and extratubular growth of neoplastic germ cells, occasionally confluent in seminoma-like infiltrates. In Cases 1 and 2, no malignant cells were found at biopsy of the contralateral testis.

CONCLUSIONS

In contrast to intratubular (in situ) germ cell neoplasia, microinvasion constitutes a definitive malignancy and the starting point of differentiation into seminoma or nonseminomatous tumor. Inguinal orchiectomy is recommended as primary therapy. The necessity of complementary therapy is an issue that must be investigated.