Multifocality in testicular germ cell tumors

Standard treatment for testicular germ cell tumor is radical orchiectomy. Several groups have suggested an organ sparing approach in patients with bilateral tumors or tumor in a solitary testis. We determined the prevalence of multifocality in testicular germ cell tumor cases.

Orchiectomy specimens from 145 consecutive patients treated for testicular germ cell tumor between 1995 and 2006 were included in the study. In the current series slides were reviewed by a single dedicated uropathologist. Multifocality was defined as 1 of 4 distinct pathological entities, including 1) distinct tumor focus conspicuously separable from the main tumor mass, 2) microinvasive tumor characterized by a single or small groups of malignant germ cells scattered within the normal interstitial parenchyma, 3) extra tumor vascular invasion and 4) rete testis invasion by pagetoid tumor spread.

Multifocality was identified in 48 patients (33%), of whom 17 (12%) had an additional distinct tumor focus, 21 (14%) had microinvasive tumor, 17 had extra tumor vascular invasion and 2 had rete testis invasion by pagetoid tumor spread. Multifocality was more prevalent in men with smaller tumors and seminomatous histology (pure seminoma or as part of a mixed germ cell tumor). Multifocality was present in 63% of men with an index mass of 2 cm or less in diameter. Study limitations include potential pathological sampling errors resulting from the retrospective design.

Multifocality is a frequent finding in testicular germ cell tumor cases that is associated with small mass size and seminomatous histology. Data suggest that additional invasive tumor outside the index mass may be present in up to 63% of men considered potential candidates for organ sparing surgery.