Goblet cell carcinoid of the rectum: a case report

Abstract

Background: Goblet cell carcinoid (GCC) is a neuroendocrine tumor usually found in the appendix. GCCs exhibit characteristic findings with mixed endocrine-exocrine features such as staining positive for neuroendocrine markers and producing mucin. The primary GCC of the rectum is exceedingly rare.

Case presentation: A 77-year-old Japanese male presented with hematochezia. Anal tenderness and a hard mass in the anal canal were found on the digital rectal examination, and colonoscopy was performed. Colonoscopy showed an irregularly shaped mass in the anal canal. Biopsy showed mixed features including adenocarcinoma in situ, well-differentiated adenocarcinoma, and mucinous carcinoma with invasive proliferation. No metastatic lesions were found on the computed tomography scan. Pelvic magnetic resonance imaging scan showed extramural growth of a tumor on the ventral side of the rectum without invasion to the prostate. Laparoscopic abdominoperineal resection was performed. The final diagnosis was well-differentiated adenocarcinoma in the mucosa and goblet cell carcinoid from the submucosa to the adventitia of the rectum. The patient was discharged from the hospital on postoperative day 16. Six months after resection, a computed tomography scan revealed multiple metastatic lesions in the liver. Several chemotherapy regimens were given, and the patient has stable disease 27 months after surgery.

Conclusion: We present a patient with rectal GCC with metachronous liver metastases. Since GCC grows intramurally and is biologically aggressive compared to typical carcinoid lesions, the disease is usually diagnosed at an advanced stage. The development of optimal adjuvant chemotherapy is needed for those patients.

Keywords: Goblet cell carcinoid; Liver metastases; Rectum.

Fig. 1

Colonoscopy 5 years prior to presentation revealed a 13-mm semi-pedunculated polyp in the rectum. a Histologic findings showed well-differentiated adenocarcinoma in situ. b (×200)

Fig. 2

Colonoscopy revealed an irregular shaped mass from the proximal anal canal to the anal verge

Fig. 3

Pelvic magnetic resonance imaging scan demonstrated the extramural growth of the tumor on the ventral side of the rectum. There was no invasion of the prostate. a Axial image. b Sagittal image

Fig. 4

Depressed and protruding lesions were found from the proximal anal canal to the anal verge macroscopically. a The surface was a gray-white mass from the submucosa to the adventitia. b Area surrounded by the red line delineates the well-differentiated adenocarcinoma component the yellow line delineates the goblet cell carcinoid component

Fig. 5

Histopathologic evaluation showed a malignant neoplasm with goblet-like cells. Malignant cells with nests were found from the submucosa to the adventitia with lymphatic and venous invasion. Components of well-differentiated adenocarcinoma were also found in the mucosa (hematoxylin and eosin ×10, a small window shows a magnified image of goblet-like cell components ×400)

Fig. 6

Adenocarcinoma components stained positive for CEA (a), CK20 (b) as epithelial marker, and negative for synaptophysin (c). Goblet-like cells stained positive for CEA (e) and CK20 (f) as epithelial markers, synaptophysin (g) as a neuroendocrine marker by immunohistochemistry. Ki-67 had a different pattern from the adenocarcinoma components (d) and GCC (h) being diffuse and peripheral in the nests for each area respectively (×20)

Fig. 7

Abdominal computed tomography scan 6 months after surgery revealed multiple metastatic lesions in the liver. A total of 5 lesions were found