Heterotopic gastric mucosa of the rectum--characterization of endocrine and mucin-producing cells by immunocytochemistry and lectin histochemistry. Report of a case

Poorly differentiated neuroendocrine rectal carcinoma with uncommon immune-histochemical features and clinical presentation with a subcutaneous metastasis, treated with first line intensive triplet chemotherapy plus bevacizumab FIr-B/FOx regimen: an experience of multidisciplinary management in clinical practice

Background

Neuroendocrine tumors (NETs) are heterogeneous, widely distributed tumors arising from neuroendocrine cells. Gastrointestinal (GI)-NETs are the most common and NETs of the rectum represent 15, 2% of gastrointestinal malignancies. Poorly differentiated neuroendocrine carcinomas of the GI tract are uncommon. We report a rare case of poorly differentiated locally advanced rectal neuroendocrine carcinoma with nodal and a subcutaneous metastasis, with a cytoplasmic staining positive for Synaptophysin and Thyroid Transcription Factor-1.

Case presentation

A 72-year-old male presented to hospital, due to lumbar, abdominal, perineal pain, and severe constipation. A whole-body computed tomography scan showed a mass of the right lateral wall of the rectum, determining significant reduction of lumen caliber. It also showed a subcutaneous metastasis of the posterior abdominal wall. Patient underwent a multidisciplinary evaluation, diagnostic and therapeutic plan was shared and defined. The pathological examination of rectal biopsy and subcutaneous nodule revealed features consistent with small-cell poorly differentiated neuroendocrine carcinoma. First line medical treatment with triplet chemotherapy and bevacizumab, according to FIr-B/FOx intensive regimen, administered for the first time in this young elderly patient affected by metastatic rectal NEC was highly active and tolerable, as previously reported in metastatic colo-rectal carcinoma (MCRC). A consistent rapid improvement in clinical conditions were observed during treatment. After 6 cycles of treatment, CT scan and endoscopic evaluation showed clinical complete response of rectal mass and lymph nodes; patient underwent curative surgery confirming the pathologic complete response at PFS 9 months.

Discussion and conclusions

This case report of a locally advanced rectal NEC with an unusual subcutaneous metastasis deserves further investigation of triplet chemotherapy-based intensive regimens in metastatic GEP NEC.

Heterotopic gastric mucosa in the anus and rectum: first case report of endoscopic submucosal dissection and systematic review

BACKGROUND

Heterotopic gastric mucosa (HGM) is the most reported epithelial heterotopia, but it is very rare in the rectum and anus.

METHODS

The first case of an asymptomatic adult male with a large nonpolypoid HGM in the low rectum underwent complete resection by endoscopic submucosal dissection (ESD) is reported. The systematic review was based on a comprehensive search of MEDLINE, EMBASE and Google Scholar. Studies on humans were identified with the term 'heterotopic gastric mucosa in the rectum and /or anus.'

RESULTS

The search identified 79 citations, and 72 cases were evaluated comprising the present report. Congenital malformations were observed in 17 (24%) patients; rectal duplication accounted for most of the cases. The HGM was located in the anus and perineal rectum in 25 cases (41%) and low, middle and proximal pelvic rectum in 20 (33%), five (8%) and 11 cases (18%), respectively. Morphology was nonpolypoid in 37 cases (51%), polypoid in 26 cases (36%) and ulcerated in nine cases (13%). Specific anorectal symptoms were reported by 50 (69%) patients of the whole study population, and by 33 (97%) of 34 patients ≤ 18 years. Complications were observed in 23 cases (32%). The HGM was excised in 50 cases (83%). Endoscopic resection was performed in 17 cases (34%); resection was piecemeal in five of 12 lesions ≥15 mm, required argon plasma coagulation in two cases and was associated with residual tissue in two (17%). Intestinal metaplasia and an adenoma with low-grade dysplasia were described in three adults (4%).

DISCUSSION

This systematic review shows that the HGM in the rectum and anus may be associated with specific rectal symptoms and serious complications, mainly in the pediatric population, and a risk of malignancy in adults. Its complete excision should be recommended, and the ESD can overcome the technical limits of conventional endoscopic snare resection and avoid unnecessary surgery.

Gastric heterotopia of rectum in a child: a mimicker of solitary rectal ulcer syndrome

Bleeding per rectum is an uncommon presentation in pediatric patients. Heterotopic gastric mucosa in the rectum is a rare cause of rectal bleeding. Here, we report a 3-year-old child with a bleeding rectal ulcer that was initially diagnosed and managed as a solitary rectal ulcer syndrome. After 1 month, the patient persisted to have intermittent rectal bleed and severe anal pain. Repeat colonoscopy showed the worsening of the rectal ulcer in size. Pediatric surgeon excised the ulcer, and histopathological examination revealed a gastric fundic-type mucosa consistent with the diagnosis of gastric heterotopia of the rectum. Over the following 18 months, our patient had experienced no rectal bleeding and remained entirely asymptomatic. In conclusion, heterotopic gastric mucosa of the rectum should be considered in the differential diagnosis of a bleeding rectal ulcer.

The immunohistochemical demonstration of Helicobacter pylori in rectal ectopia

The finding of heterotopic gastric mucosa in the rectum is rare, with less than 40 reported cases in the literature. A condition of unknown etiology, several hypotheses exist including infectious and congenital. We report a case of ectopic gastric tissue in the rectum of a 47-year-old female, and her subsequent clinical course. Furthermore for the first time, we present immunohistologic evidence of the presence of Helicobacter pylori in rectal ectopic gastric tissue.

Large right atrial myxoma containing gastric heterotopia presenting with dyspnea and bilateral leg edema due to pulmonary emboli and cardiovascular obstruction: the first known report of gastric heterotopia in the cardiovascular system

A 52-year-old male presented with progressive dyspnea, bilateral leg edema, and elevated central venous pressure due to a large right atrial myxoma that caused vascular obstruction and pulmonary emboli. The myxoma contained gastric heterotopia. Other unusual features of this atrial myxoma included its large size, right atrial location, and attachment to the right atrial wall. Although gastric heterotopia has been reported throughout the gastrointestinal tract, and occasionally in other organs, this is the first report of gastric heterotopia in the cardiovascular system. This report confirms and extends previous reports of glandular elements or enteric glands within atrial, or cardiac, myxomas. The clinical presentation of the currently reported patient is explained as follows: the elevated central venous pressure resulted from cardiovascular obstruction and the dyspnea from multiple pulmonary emboli due to the large atrial myxoma. In this case, the clinical presentation was not attributable to the gastric heterotopia. The association of gastric heterotopia with atrial myxoma may, however, be clinically important because of the propensity of gastric heterotopia in the gastrointestinal tract to produce complications. The reported association may provide clues to the histogenesis of these two entities.

Heterotopic Gastric Mucosa of the Anus: A Case Report and Review of the Literature

Ectopic gastric mucosa has been described at various locations of the body, including all levels of the gastrointestinal tract. However, this finding is rare in the rectum and anus, with 38 reported cases. In only six cases, including the present one, has the heterotopic tissue been located within 2 cm of the dentate line. We report a case of gastric heterotopia discovered in a 21-year-old male who presented with anal pain and pruritis. Flexible sigmoidoscopy demonstrated an anal polyp, and biopsy confirmed fundic-type gastric tissue. A 99mtechnetium-pertechnetate scan confirmed increased uptake in the anus. After minimal clinical improvement with proton-pump inhibitors, the patient underwent local surgical excision and remains symptom-free at a follow-up of 9 months. We review the potential etiologies, clinical manifestations, treatment options, and patient outcomes.

Gastric heterotopic mucosa in the rectum with Helicobacter pylori-like organisms: a rare cause of rectal bleeding

We report the case of a 9-year-old boy who presented with chronic rectal bleeding. On proctosigmoidoscopy, a polypoid elevation in the rectal ampulla measuring 5 x 3 cm was found. Biopsies were reported to show gastric mucosa. The Giemsa stain showed Helicobacter pylori-like organisms. Including our patient, there are now 30 similar cases reported in the medical literature. The usual manifestations of this rare entity are chronic bleeding and rectal pain. In one-half of cases there is chronic rectal ulceration. The recommended treatment is transanal surgical resection unless there is rectal peptic ulceration. H2 receptor blockers are then advised. Surgical excision is carried out after healing has taken place.