Extremely Rare Synchronous Primary Neoplasms of Meckel’s Diverticulum and Colon: a Report of Three Cases

Abstract

Synchronous primary neoplasms of Meckel’s diverticulum and colon malignancies are rarely reported in the literature. We present three patients with synchronous primary neoplasms of Meckel’s diverticulum and colon malignancies. All tumors located in Meckel’s diverticulum were incidentally found at laparotomy and the definitive diagnosis was made with microscopic examination of surgical specimens. Synchronous primary neoplasms of Meckel’s diverticulum and colon malignancies are rarely encountered. Moreover, this is the first case of synchronous colon cancer and pancreatic intraepithelial neoplasia (PanIN) arising from pancreatic heterotopia within Meckel’s diverticulum. The diagnosis of Meckel’s diverticulum should be kept in mind in patients who underwent laparotomy for any reason; when found incidentally at laparotomy, it should be carefully examined for any suspicious abnormality and surgery should be considered that it can be performed without any problems.

Introduction

Meckel’s diverticulum (MD) is the most common congenital anomaly of the gastrointestinal tract and is a true diverticulum located on the antimesenteric side of the ileum. It originates from incomplete closure of the omphalomesenteric duct in fetal life and is seen in 2–4% of population-based studies [1]. Most patients are asymptomatic and the diagnosis is usually made incidentally during radiological investigations or at elective surgery for other intra-abdominal diseases. But, Meckel’s diverticulum can cause serious complications such as bleeding, obstruction, diverticulitis, or perforation and surgery can be inevitable. Additionally, different tumor development in Meckel’s diverticulum was reported only in 0.5–3.2% [1]. Alternatively, in some patients with a neoplasm arising in MD synchronous with other gastrointestinal tumors is extremely rare.

Here, we discuss synchronous colon tumor and neoplasms arising in MD in three patients with relevant literature.

Case 1

An 82-year-old man was admitted to the outpatient clinic with abdominal pain, changed bowel habits, and left giant scrotal hernia. Abdominal computed tomography showed circumferential thickening of the sigmoid colon wall associated with adjacent pericolic lymph nodes, but no distant metastasis. Colonoscopic examination revealed a vegetative, reddish, irregularly shaped mass located in the sigmoid colon, 30 cm from the anus; thus, endoscopic biopsy was taken. Histopathological examination showed a moderately differentiated adenocarcinoma of the colon. Sigmoid colectomy with stapled colocolonal anastomosis and left inguinal hernia repair with polypropylene mesh were performed. Surprisingly, MD was found during intraoperative exploration. Subsequently, because MD had a vague nodule at the tip, diverticulectomy was performed and the operation was completed without any complication. Histopathological examination of the colon revealed a moderately differentiated adenocarcinoma located in the sigmoid colon. Microscopic examination of the MD showed a tumor located in the muscularis propria of the organ, which was 1.5 cm in diameter. It was composed of spindle cells with no significant atypia and no mitosis (Fig. 1). Immunohistochemistry demonstrated the following: CD117 ( +), DOG1 ( +), CD34 focal ( +), desmin ( −), SMA ( −), S-100 ( −), and Ki67. So the histopathologic features and immunohistochemical staining pattern were consistent with GIST with no risk. The early postoperative period was uneventful and the patient was discharged on the 8th day. The patient was administered adjuvant chemotherapy for sigmoid colon cancer. He is alive 4 years after the resection with no evidence of disease after surgery.

Fig. 1.

A GIST of Meckel’s diverticulum wall (H&E, × 2). B Immunohistochemically, spindle cell positivity for CD117 (× 10)

Case 2

A 62-year-old male patient was admitted to the emergency department with signs and symptoms of acute abdomen. The patient was operated with the pre-diagnosis of mechanical colon obstruction. A large obstructive sigmoid colon tumor and Meckel’s diverticulum were found at the exploratory laparotomy. Sigmoid colon resection and end-to-end anastomosis for the sigmoid tumor, and, additionally, diverticulectomy of MD were performed. On histopathological examination, the tumor in the sigmoid colon was reported as moderately differentiated adenocarcinoma and the tumor in MD was reported as well-differentiated neuroendocrine tumors (NETs) (Fig. 2). The patient was discharged on the 10th postoperative day without any problem and postoperative adjuvant chemotherapy was performed for the sigmoid colon. The patient is alive with no evidence of disease at the end of the 8-year follow-up.

Fig. 2.

A Neuroendocrine tumor in Meckel’s diverticulum wall (H&E, × 4). B Diffuse chromograninpositivity of the tumor cells (× 10)

Case 3

A 62-year-old male patient was admitted to the outpatient clinic with a big mass located in the right lower quadrant of the abdomen. It was diagnosed as cecal tumor. Right hemicolectomy was performed. But also, MD was incidentally found during laparotomy and diverticulectomy was done. On histopathological examination, the tumor in the cecum was reported as moderately differentiated adenocarcinoma and the tumor in MD was reported as gastric and pancreatic heterotopia harboring pancreatic intraepithelial neoplasia (PanIN) in MD (Fig. 3).

Fig. 3.

A Pancreatic and gastric heterotopia in the MD wall (H&E, × 4). B PanIN Ia in the pancreatic duct (HE, × 4)

The postoperative period was uneventful and the patient was discharged home 7 days later. This patient was administered adjuvant chemotherapy for cecal cancer. The patient is alive with no evidence of disease at the end of the 3-year follow-up.

Discussion

Tumors developing in MD are infrequent, Thirunavukarasu et al. reported NET to be the most common malignancy developing in MD (76.5% of cases). It is followed by adenocarcinoma (11.4%), GIST/leiomyosarcoma and sarcoma (10.8%), and lymphoma (1.3%) and others [1].

Alternatively, synchronized primary GIS tumors and primary neoplasms arising from Meckel’s diverticulum are very rarely reported in the literature. In all of these articles, it was not possible to make a diagnosis on preoperative imaging studies, and it is seen that diverticulectomy was usually performed. The definitive diagnosis in these patients was determined by the histopathological examinations performed postoperatively. Likewise, in the presented study, the definitive diagnosis could only be made after histopathological examination in the patients.

GISTs are rare tumors, accounting for less than 1% of all primary GIS malignancies. The exact pathogenesis is not completely known in GIST; however, they originate from stromal cells of Cajal. These tumors are most commonly found in the stomach (60%), small bowel (25%), rectum (10%), and esophagus (5%) and rarely seen in the duodenum, omentum, and peritoneum. When GISTs are examined immunohistochemically, CD117 (kit protein) positivity and DOG-1 positivity are observed in almost all cases (98–100%), CD34, 70–80%; smooth muscle actin, 20–40%; S100, 5%; and desmin, 1–2% [2]. GIST development is rare in MD [3]. Preoperative diagnosis of tumors within MD is difficult. Most of the cases are diagnosed at laparotomy and by the histopathologic examination of the specimen. Although the coexistence of GISTs with other primary gastrointestinal carcinomas was described many times before, synchronous colorectal adenocarcinoma and GIST in MD are extremely rare [3, 4]. According to the English literature, this case is the second report of synchronous colorectal adenocarcinoma and GIST in MD [2].

NETs are neoplasms that originate from neuroendocrine cells anywhere in the body. They are most common in the gastrointestinal tract (70%) and respiratory system (25%). Most NETs arising from MD have been reported as isolated case reports in the literature and found incidentally, with over half of the cases with no symptoms. Nies et al. analyzed a series of 106 patients with NET arising in MD. They reported that 64% of patients with NET in MD are asymptomatic at the time of the diagnosis, and 27 patients were incidentally discovered at autopsy [4]. Different types of serum biomarkers such as serotonin, pancreastatin, and chromogranin A may be used to help for diagnosis of NET. In the literature, it was reported that synchronous colorectal carcinoma and NET in MD are rare [5]. In our patient, all of the clinic symptoms and signs were due to mechanical intestinal obstruction caused by sigmoid colon tumor, and there were no clinical and laboratory findings of NET in MD. It was incidentally detected in the pathologic evaluation.

As known, heterotopic pancreas is defined as the presence of pancreatic tissue abnormally located anywhere in the body. The prevalence of this embryological abnormality was reported as < 1.0 to 6% in Meckel’s diverticulum and it is usually asymptomatic and is found incidentally; it can occasionally cause symptoms and rarely malignant transformation occurs [6].

In no doubt, various types of pancreatic tumors may arise in heterotopic pancreas tissue. PanIN is one of them and is a precancerous lesion and very rarely encountered in MD [7]. On the other hand, we would like to emphasize that the 3rd patient is the first reported with the unique characteristic of synchronized colon tumor and PanIN of the heterotopic pancreatic tissue located in MD.

Surgery is the mainstay of treatment for symptomatic patients with complications due to MD. However, whether all incidentally found MD should be resected or not is still debating. Most of the surgeons accept that when asymptomatic MD incidentally is found during abdominal surgery due to other causes, to obtain favorable outcomes, they make their decision depending on various factors such as the patient’s age, clinical condition, and morphological structure of MD [8].

In conclusion, synchronous primary neoplasms of Meckel’s diverticulum and colon are rare situation. When Meckel’s diverticulum is found, even looking like normal at laparotomy or laparoscopy for GIS malignancies, it should be kept in mind that there is a possibility of a tumor of Meckel’s diverticulum. Although, whether all incidentally found MD should be resected or not is still debating, the surgeon should make a decision based on the patient’s individual circumstances.

Declarations

Informed Consent

Written informed consent was obtained from the patient who participated in this study and also to publish photos of the patient.

Conflict of Interest

The authors declare no competing interests.