In patients with residual lesions <1 cm, the role of PC-RPLND is discussed controversially based on the finding that up to 20 and 8 % of patients will harbour mature teratoma and vital cancer. However, this approach has been challenged by recent retrospective studies from three groups. Kollmannsberger et al. [4] analysed 276 patients who underwent systemic chemotherapy for metastatic NSGCT. One hundred sixty-one (58.3 %) achieved a complete remission (residual lesions <1 cm), and all patients were followed without surgical resection. After a mean follow-up of 40 (2–128) months, relapses were observed in 6 %, and none of them died after appropriate salvage therapy. Ninety-four percent of the patients belonged to the IGCCCG good prognosis group. Ehrlich et al. [5] evaluated 141 patients who were observed after systemic chemotherapy and had residual lesions <1 cm. After a mean follow-up of up to 15 years, 9 % of the patients relapsed and 3 % of the patients died due to testis cancer. IGCCCG risk group classification predicted the outcome best: recurrence-free survival and cancer-specific survival were 95 and 99 %, respectively, in men who belonged to the good risk group, whereas it dropped to 91 and 73 % in the intermediate and poor risk group. The German Testicular Cancer Study Group (GTCSG) analysed the outcome of 392 patients who underwent PC-RPLND for residual lesions of any size [6]. 9.4 and 21.8 % of the men with residual lesions <1 cm harboured vital cancer and mature teratoma, respectively. These numbers increased to 21 and 25 % in patients with residual lesions of 1–1.5 cm and to 36 and 42 % in men with lesions larger than 1.5 cm.

Based on these data, PC-RPLND for small residual masses might only be indicated in patients with (1) intermediate or poor prognosis at initiation of chemotherapy and/or (2) >50 % teratoma in the orchiectomy specimen. The remainder can be managed conservatively with close follow-up.

In patients with residual masses at multiple sites, an individual decision should be made regarding the number and extension of resections based on the risk of relapse and on quality-of-life issues [1–3]. Resection of residual tumours outside the abdomen or lung should also be considered on an individual basis, since discordant histology is found in 35–50 % of patients. Pulmonary or mediastinal residual masses harbour necrosis/fibrosis in 90 % if the retroperitoneal masses did not contain mature teratoma or viable cancer [7, 8]. Management of liver lesions by postchemotherapy retroperitoneal lymph node dissection must be individualised. Observation may be warranted for liver lesions requiring complicated hepatic surgery regardless of retroperitoneal pathology [9]. The concordance between retroperitoneal and liver histology was 49 % overall, including 94 % for necrosis, 26 % for teratoma and 36 % for cancer. Liver necrosis alone was found in 94, 70 and 50 % of patients with retroperitoneal necrosis, teratoma and cancer, respectively.

PC-RPLND should be initiated within 6–12 weeks after chemotherapy. Hendry et al. retrospectively analysed the outcome of 443 patients undergoing either immediate or elective PC-RPLND once progression of the residual masses was demonstrated [11]. A significant benefit with regard to progression-free survival (83 % versus 62 %, p = 0.001) and cancer-specific survival (89 % versus 56 %, p = 0.001) was identified for the immediate surgical approach.