John L Fletcher, MD, Alfred F Trappey, MD, Michelle L Josey, MD, Kevin J Krauland, MD, Valerie G Sams, MD. San Antonio Military Medical Center
Appendiceal neoplasms are a rare, though well-recognized, cause of perforated appendicitis. Adenocarcinoma of the appendix represents 0.5% of all gastrointestinal malignancies and includes subtypes of mucinous (55%), colonic type (34%), and carcinoid-adenocarcinoma (11%) which has mixed morphology. The histomorphologic spectrum varies from predominantly classical carcinoid to predominantly adenocarcinoma and when discovered, these tumors are often found at late stage which generally connotes a poor prognosis.
A 47-year old male with 24 hours of acute onset right lower quadrant pain, nausea, vomiting and leukocytosis was diagnosed with perforated appendicitis following a CT scan which demonstrated a peri-appendiceal abscess and phlegmon. He was started on IV antibiotics, admitted to the hospital and underwent percutaneous drain placement in interventional radiology. His leukocytosis resolved and he was discharged to home with oral antibiotics. Following continued improvement and a decrease in his drain output the drain was removed. Thirty days after his initial diagnosis and 2 weeks after drain removal he returned to the emergency room with a recurrence of his pain, leukocytosis and fever.
Due to failure of non-operative management (NOM) he underwent laparoscopic appendectomy, admission with IV antibiotics with an uncomplicated post-operative course. Intraoperative findings were notable for a phlegmonous collection of tissues with mucinous drainage adherent to the clearly perforated appendix. Final pathology demonstrated a mixed goblet cell carcinoid-adenocarcinoma with significant signet-ring cell component which extended to the staple line. The tumor demonstrated aggressive features with lymphovascular invasion and perineural invasion with an initial pathologic staging of pT2pN0pMX.
Tumor markers, a CT scan of the chest, an esophagoduodenoscopy and colonoscopy were performed without evidence of metastatic disease. Consequently he underwent diagnostic laparoscopy which showed no evidence of intraperitoneal disease and a formal laparoscopic, hand-assisted right hemicolectomy was performed. His post-operative course has been uncomplicated and his final pathologic staging remained putting him at stage I disease with all margins clear and no positive lymph nodes or intraperitoneal disease. The patient is currently being followed with surveillance tumor markers and imaging to monitor for recurrence of disease. Due to the early stage of disease, the patient will not undergo systemic chemotherapy or intraperitoneal chemotherapy. To our knowledge based on an exhaustive review, this represents the earliest stage of carcinoid-adenocarcinoma described in the literature.
Malignancy remains a rare, though complicated, etiology of appendicitis in the adult population. With NOM for perforated appendicitis an increasingly accepted practice, recurrence or failure of NOM should raise the surgeon’s suspicion for malignancy and a low-threshold for appendectomy should be maintained.