INCIDENTAL DIAGNOSIS OF CECAL APPENDIX PHEOCHROMOCYTOMA IN A PATIENT UNDERGOING LAPAROSCOPIC APPENDECTOMY: A RARE CASE

Case Presentation A 26-year-old white female from Uberaba presented with a chronic history of mid-abdominal colicky pain, associated with nausea and excessive flatulence. She was admitted to the emergency department due to exacerbation of pain for the past 3 days, with abdominal distension and cessation of stool and gas passage after the onset of symptoms. She denied fever, chills, anorexia, urinary changes, or previous similar episodes. The patient was previously healthy, using only oral contraceptives. On physical examination, she was in good general condition, afebrile, with a tense abdomen, diffusely tender on palpation, with increased pain in the right iliac fossa, along with guarding and positive rebound tenderness in this region. A contrast-enhanced abdominal CT scan was performed, revealing findings consistent with acute appendicitis and diffuse thickening of the cecal appendix. The patient underwent laparoscopic appendectomy without complications, and the pathological analysis of the specimen revealed significant thickening of the appendix wall at the base. The histopathological study showed an epithelioid neoplasm with expansive growth and perivascular involvement, with cells having ample cytoplasm, sometimes clear, sometimes eosinophilic granular, with a tendency to merge with the adjacent muscle layer and without nuclear atypia. The immunohistochemical analysis was positive for smooth muscle actin and GP100 protein, and negative for other antibodies, confirming the diagnosis of PEComa of the cecal appendix. Thoracic and pelvic CT scans were performed, showing no abnormalities.

Discussion PEComas (Perivascular Epithelioid Cell Tumors) are mesenchymal-origin tumors with typically benign behavior, although they have the potential for malignancy. Histologically, they are characterized by epithelioid cells with perivascular growth and immunoreactivity for melanocytic and smooth muscle markers. The occurrence of this pathology is rare, and most individuals are asymptomatic, with incidental diagnosis found during imaging studies or analysis of surgical specimens. Surgical treatment is the most common approach.

Conclusion Given the rarity of this condition and the limited data in the literature, further studies are needed to establish the ideal management and treatment, especially for malignant cases. Well-established diagnostic methods are crucial for the correct identification of this entity and distinguishing it from other differential diagnoses.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025