Atypical florid vascular proliferation in appendix: a diagnostic dilemma

Area of Science:

• Gastroenterology and Surgical Pathology
• Vascular Lesions
• Appendiceal Neoplasms

Background:

• Intestinal vascular abnormalities are uncommon, with angiodysplasia being the most frequent type.
• Appendiceal lesions are rare, and vascular tumors are exceptionally infrequent.
• Accurate diagnosis of appendiceal masses is crucial for appropriate patient management.

Observation:

• A 41-year-old male presented with melena, indicating gastrointestinal bleeding.
• Colonoscopy revealed blood clots in the appendiceal orifice, leading to laparoscopic appendectomy.
• Microscopic examination identified a polypoid mass with pyogenic granuloma-like superficial features and deeper infiltrative vascular proliferation.

Findings:

• The appendiceal mass exhibited florid vascular proliferation with minimal endothelial atypia and infrequent mitoses.
• Immunohistochemistry showed positivity for CD31 and CD34, and negativity for HHV-8.
• The lesion did not conform to any established vascular tumor or sarcoma classification, leading to a diagnosis of atypical florid vascular proliferation.

Implications:

• This case highlights a rare and undefined vascular lesion of the appendix.
• The findings expand the differential diagnosis for appendiceal masses and vascular tumors.
• Successful surgical management resulted in a favorable short-term outcome, emphasizing the importance of thorough histopathological evaluation.