Appendiceal signet ring cell carcinoma masquerading as acute appendicitis: a case report

Appendiceal signet ring cell carcinoma (ASRCC) is a rare and aggressive malignancy of the appendix. It often presents with nonspecific symptoms resembling acute appendicitis, making early diagnosis challenging. Prompt recognition and appropriate management are essential to improve outcomes. A 28-year-old gentleman presented with pain in the right lower abdomen for 2 weeks, associated with low-grade fever. Abdominal examination revealed tenderness and guarding in the right lower quadrant. Computed tomography (CT) of the abdomen revealed a retrocaecal appendix with severe acute appendicitis, appendicular tip perforation, and a peri-appendicular collection. The patient underwent laparoscopic drainage of the abscess with appendectomy. Histopathological examination of the specimen revealed signet ring cell carcinoma of the appendix. Further staging evaluation was performed, following which the patient underwent cytoreductive surgery comprising right hemicolectomy and regional lymphadenectomy, along with hyperthermic intraperitoneal chemotherapy (HIPEC). Histopathological examination established the diagnosis of appendiceal signet ring cell carcinoma following an initial presentation as perforated acute appendicitis. The patient subsequently underwent definitive oncological management with cytoreductive surgery and HIPEC. A comprehensive review of the available literature was also undertaken, focusing on the clinical presentation, histopathological characteristics, proposed pathogenesis, treatment strategies, and prognosis of ASRCC. Appendiceal signet ring cell carcinoma is an uncommon but highly aggressive malignancy that may mimic acute appendicitis, particularly in cases presenting with perforation or peri-appendicular abscess. Histopathological examination of appendectomy specimens is crucial for detecting unexpected malignancy. Early diagnosis, appropriate staging, and timely multidisciplinary oncological management, including cytoreductive surgery and HIPEC in selected patients, may improve clinical outcomes.