Abstract
Background: We encountered a case of endometriosis with left inguinal induration. The lesion was initially diagnosed by aspiration cytology as a metastatic adenocarcinoma of the lymph node. We present a retrospective review of the case, focussing on the cytology.
Case: The patient was a 43-year-old woman with a left inguinal induration. Sonography and computed tomography of the lesion strongly suggested a metastatic carcinoma of the lymph node. The aspirated sample was allegedly obtained from the lymph node. Epithelial cell clusters intermingled with necrotic debris were observed in the cytology. Although the epithelial cells exhibited some atypical features, we regarded the cells as originating from an adenocarcinoma because they were obtained from the lymph node and the possibility of endometriosis was not considered. The primary adenocarcinoma site, however, could not be found. The lesion was excised, and a histological examination of the specimen showed endometriosis of the left inguinal soft tissue involving the lymph node.
Conclusion: A retrospective review of this case suggests that the presence of epithelial cells in cytological examinations of lymph node tissue does not necessarily imply the presence of carcinoma cells. The cytologic characteristics of the cells should be carefully confirmed. In view of the current increase in the incidence of endometriosis, the possibility of endometriosis in cases like this one should be considered.
