Immunohistochemical evaluation of endometriotic lesions and disseminated endometriosis-like cells in incidental lymph nodes of patients with endometriosis

Objective To investigate the frequency of endometriotic lesions and disseminated endometriotic-like cells in a series of incidentally removed lymph nodes (LNs) in patients with endometriosis. Design Retrospective study. Setting University hospital endometriosis center. Patient(s) Premenopausal patients underwent surgery because of endometriosis-associated symptoms. Intervention(s) Retrospective analysis of 108 coincidentally resected LNs of 24 patients with endometriosis. To identify endometriotic cells, immunohistochemical analysis of estrogen and progestogen receptor (ER-PR), CD10, and cytokeratin was performed. Mean Outcome Measure(s) The occurrence of endometriotic lesions (ER-PR, CD10, and cytokeratin positive) and disseminated endometriotic-like ER-PR–positive cells in LNs. Result(s) Deep infiltrating endometriosis was diagnosed in 23 of the 24 patients with incidentally removed LNs. In 8 of 24 (33.3%) patients with incidentally removed LNs, typical endometriotic lesions were detected. Disseminated ER-PR–positive cells were found in 17 of 24 patients (70.8%). Lymph node involvement correlated directly with the deep infiltrating endometriosis lesional size. Conclusion(s) Estrogen receptor–progestogen receptor–positive endometriotic lesions and disseminated endometriotic-like cells frequently are detected in LNs of patients with deep infiltrating endometriosis and, therefore, might reflect “nonlocalized” disease. If clinical significance of such lesions were provided, adjuvant hormonal treatment could be considered as a possible additional mode of therapy.