Surprise in hernia sacs: Malignant tumor metastasis

Background/Aim: Malignant tumors are rare in the hernia sac, and there are very few studies on this subject in the literature. We aimed to investigate the malignancies in surgically resected hernia sacs and their clinicopathological features in the last ten years in our institution. Methods: The hernia sac specimens sent for pathological examination between 2010 and 2021 were included in this retrospective cohort study. The age and gender of the patient, the type of hernia and known malignancy history of all patients were recorded. Cases with malignancy in the hernia sac were selected and their slides were re-evaluated. The cases with and without malignancy in the hernia sac were compared in terms of age, gender and known cancer history. Results: There were 455 hernia sac specimens belonging to 448 patients which underwent pathological examination between 2011 and 2021. Malignancy was detected in ten (2.20%) hernia sacs. Eight were malignant tumor metastases (1.75%). The remaining two were secondary involvement of another malignancy. Five malignant tumors were ovarian serous carcinoma, one was vulvar squamous cell carcinoma, one was appendiceal mucinous cystadenocarcinoma, one was malignant melanoma metastasis, one was undifferentiated pleomorphic sarcoma, and one was non-Hodgkin lymphoma. The incidence of hernia sac malignancy was similar in male and female patients (3.5% and 1.4%, respectively; P=0.190). There was a known cancer history in 70% (n=7) of ten patients with malignancy in the hernia sac. The incidence of malignancy in the hernia sacs of patients with a known cancer history was significantly higher (P<0.001). Malignancies were present in 0.95% (n=2) of inguinal hernias, 1.67% (n=2) of abdominal hernias and 5.45 % (n=6) of incisional hernias. Gross pathology was detected in the macroscopic examination of all malignant inguinal hernias, but not in any of the abdominal hernias. Conclusion: We recommend the microscopic examination of hernia sacs, even if there is no macroscopic abnormality, especially in the elderly and/or patients with a history of malignancy, in order to detect incidental metastases.