P2256 - A Rare Case of Intraluminal Appendiceal Tubulovillous Adenoma

Tapasya Raavi, MBBS, MPH¹, Talha Bin Farooq, MBBS¹, Nina Amilineni, MD², Ikechukwu Uzoaru, MD^2
1Carle Foundation Hospital, Champaign, IL; ²Carle Foundation Hospital, Urbana, IL

Introduction: Neoplasms of the appendix are rare, can be asymptomatic and found incidentally, or can present as acute abdomen from appendicitis, intussusception, appendiceal rupture or a palpable mass and abdominal distention. While carcinoid tumors are the among the most common appendiceal tumors, tubulovillous adenomas (TVAs) are benign and rare.

Case Description/Methods: An elderly gentleman with history of diverticulitis, was admitted with complaints of nausea, right lower quadrant (RLQ) abdominal pain and weakness. He had stable vital signs and bilateral lower quadrant abdominal tenderness on examination. Initial investigational workup revealed a leukocytosis of 19.8*10³/uL, hemoglobin at baseline of 10 g/dL, procalcitonin of 0.09ng/mL, C-reactive protein of 2.78mg/dL, creatinine 2.35 mg/dL, a urinalysis with large leukocyte esterase and urine WBC of 573/uL. CT scan of the abdomen and pelvis showed thickening of the distal appendix with trace appendiceal stranding, findings suggestive of early appendicitis and possible early sigmoid colitis. He was started on empiric broad-spectrum antibiotics for possible appendicitis and a urinary tract infection. His blood culture showed no growth and urine culture showed 40 *10³ cfu/ml of Candida albicans. He had persistent RLQ tenderness, up trending leukocytosis, up to 23.9 *10³/uL despite antibiotic therapy. A repeat CT scan about 5 days later showed persistent dilatation of the distal appendix with no evidence of adjacent inflammatory changes. He then underwent a laparoscopic appendectomy for failed medical management of acute appendicitis. An inflamed non-perforated appendix was resected and sent for histopathology examination, that showed a TVA involving the lumen of the appendix. The appendiceal margins were negative for the adenoma, with no changes of dysplasia or malignancy. His clinical condition improved shortly after the surgery and he was discharged on oral antibiotic therapy.

Discussion: TVAs of the appendix may present with a picture similar to acute appendicitis, the likely pathophysiology being luminal obstruction from the tumor. The propensity of villous adenomas to develop into invasive adenocarcinoma is unchanged despite the appendiceal origin. The mainstay of treatment for TVAs remains appendectomy, though most diagnoses of TVA are made on biopsy post appendectomy. Follow-up surveillance colonoscopies are recommended to exclude synchronous neoplasms of the gastrointestinal tract.


Figure: Histopathology slide showing intraluminal tubulo-villous adenoma of the vermiform appendix with negative appendiceal margins


Disclosures:
Tapasya Raavi indicated no relevant financial relationships.
Talha Bin Farooq indicated no relevant financial relationships.
Nina Amilineni indicated no relevant financial relationships.
Ikechukwu Uzoaru indicated no relevant financial relationships.


Tapasya Raavi, MBBS, MPH¹, Talha Bin Farooq, MBBS¹, Nina Amilineni, MD², Ikechukwu Uzoaru, MD². P2256 - A Rare Case of Intraluminal Appendiceal Tubulovillous Adenoma, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.