Metastatic inguinal nodes from an unknown primary neoplasm. A review of 56 cases.

Fifty-six cases of this uncommon neoplastic manifestation are presented. These cases represent 0.065% of 86,589 new cases of malignant disease seen at The Princess Margaret Hospital from 1968 to 1982. There were 29 men and 27 women. The median age at presentation was 58 years. Three major groups were identified: inguinal disease, 24 cases; unilateral inguinal plus iliac disease, 16 cases; local plus systemic disease, 16 cases. Pathologic subtypes were anaplastic, 24; squamous, 11; adenocarcinoma, nine; melanoma, nine; and others, three. Survival at 5 years for all patients was 27%. Among 40 patients who presented with inguinal and inguinal plus iliac disease, survival was 37.5% at 5 years. Initial treatment following biopsy was radiation in 35, lymph node dissection in eight, and chemotherapy in four. Excisional biopsy only was performed in nine cases. There were no treatment-related deaths. The findings observed in this study, in which radiation therapy was employed as initial management in the majority of cases, suggests that radiation therapy is a valid alternative to surgery in the management of this disease.