Introduction: Lymph node (LN) status is one of the main prognostic factors in localized prostate cancer (CaP) patients after surgery. Examining palpable lymph nodes with hematoxylin and eosin (HE) is the most common approach in clinical practice; however, immunohistochemistry (IHC) has been reported to increase the LN detection rate. We reviewed the oncological results of patients with LN metastasis detected by IHC. Extended lymphadenectomy was performed with complementary indocyanine green (ICG) guidance. Three groups were considered according to LN status. Definition of the pN+ group was made if LNs were detected by HE, occulted lymph node-positive (OLN+) was considered when ≥ 1 LN was identified with IHC and occulted lymph node-negative (OLN-) if no metastatic nodes were found. Oncological outcomes were reported regarding PSA kinetics, biochemical recurrence (BCR), need for secondary treatments and metastasis-free survival (MFS).
Conclusion: Conventional HE histological analysis underdiagnosed nearly 10% of patients. IHC-detected patients were at higher risk of metastasis development than OLN – patients. This report highlights the importance of optimizing the anatomopathological analysis properly.