Colonic lipoma covered by hyperplastic epithelium: Case report

Intestinal "Piggybacking Lipoma", A Unique Lipoma Composed of Lipoma and Overlying Epithelial Lesions: A Case-control Study and Review of Literature

BACKGROUND/AIM

Lipomas are rare but the most common benign mesenchymal lesions of the gastrointestinal (GI) tract, composed of mature adipose cells. The "piggybacking lipoma" is formed by lipomas with overlying polypoid epithelial lesions, such as sessile serrated lesion, tubular adenoma, or hyperplastic polyp, and the literature on these lesions is limited. In this study, we systematically investigated the clinical, endoscopic, and pathologic characteristics of these unique lipomas.

PATIENTS AND METHODS

This is a single-institution retrospective study of gastrointestinal tract lipomas diagnosed from 2016-2021. Those with concurrent polypoid epithelial or mesenchymal lesions during the same endoscopic episode were included and reviewed in this study, and the lipomas were classified as "piggybacking lipoma" or "non-piggybacking lipoma" depending on whether the concurrent lesion was overlying the lipoma or was at a different location in the intestine. Demographic, clinical, and endoscopic data were obtained from electronic medical records.

RESULTS

A total of 100 lipomas with concurrent epithelial or mesenchymal lesions were included in this study. Among them, 21 cases were classified as "piggybacking lipoma" and 79 were classified as "non-piggybacking lipoma". Patients with piggybacking lipomas showed a female predilection, and were more likely to be symptomatic and less likely to exhibit classic endoscopic features of lipoma. Histologically, the piggybacking polyps showed overlying sessile serrated lesions (SSL) (76.2%) and tubular adenoma (TA) (19%), whereas the non-piggybacking group had differing characteristic lesions with TA (57.5%) and SSL (6.0%).

CONCLUSION

Piggybacking lipomas are rare lipomas with overlying polypoid epithelial lesions, most commonly SSL. They present different clinical, endoscopic, and pathologic features compared to non-piggybacking lipomas.

Ileal collision tumor associated with gastrointestinal bleeding: A case report and review of literature

BACKGROUND

Collision tumors involving the small intestine, specifically the combination of a hamartomatous tumor and a lipoma, are extremely rare. To our knowledge, no previous case report has described a collision tumor composed of two benign tumors of different origins in the small intestine.

CASE SUMMARY

Here, we present the case of an 82-year-old woman who presented with hemorrhagic shock and was found to have a mass measuring approximately 50 mm × 32 mm × 30 mm in the terminal ileum. Based on computed tomography scan findings, the mass was initially suspected to be a lipoma. A subsequent colonoscopy revealed a pedunculated submucosal elevation consisting of two distinct parts with a visible demarcation line. A biopsy of the upper portion suggested a juvenile polyp (JP). Owing to the patient's advanced age, multiple comorbidities, and poor surgical tolerance, a modified endoscopic submucosal dissection was performed. Histopathological examination of the excised mucosal mass revealed a lipoma at the base and a JP at the top, demonstrating evidence of rupture and associated bleeding. The patient's overall health remained satisfactory, with no recurrence of hematochezia during the six-month follow-up period.

CONCLUSION

This case report provides new evidence for the understanding of gastrointestinal collision tumors, emphasizing their diverse clinical presentations and histopathological characteristics. It also offers diagnostic and therapeutic insights as well as an approach for managing benign collision tumors.

Large colonic lipoma with a laterally spreading tumor treated by endoscopic submucosal dissection: A case report

BACKGROUND

Since fat does not transmit electrical energy well, delayed perforation and post-polypectomy syndrome due to electrical thermal injury are concerns in the endoscopic removal of colonic lipoma. The endoscopic submucosal dissection (ESD) technique concentrates electrical energy conducts to the submucosa, not the adipose tissue. This helps to minimize electrical thermal injury, especially in the case of large colonic lipomas. In rare cases, such as colonic lipomas accompanied by mucosal lesions, it is difficult for endoscopists to decide how to safely remove them.

CASE SUMMARY

A 78-year-old man underwent colonoscopy for colorectal cancer screening. During colonoscopy, a yellowish submucosal tumor with positive cushion sign was observed in the ascending colon measuring about 4.5 cm. A nodular mucosal lesion of about 2.5 cm was observed on the mucosal surface of the lipoma. The lipoma was so large that it occupied much of the inside of the colon, making it difficult to see the entire laterally spreading tumor (LST) at once. The LST was confined to the surface of the lipoma, which had a semipedunculated shape with a wide neck. The margin of the LST was not observed at the neck of the lipoma. ESD was performed and the colonic lipoma with the LST was successfully removed without complications. After 3 d of hospitalization, the patient was discharged without any symptoms. The final pathology report showed that the lesion consisted of submucosal lipoma and tubulovillous adenoma with low-grade dysplasia.

CONCLUSION

ESD is effective and safe for treating a large colonic lipoma with an LST by minimizing electrical thermal injury.

Giant Colonic Lipoma Presenting as Intermittent Colonic Obstruction With Hematochezia

Colonic lipomas are rare benign, non-epithelial tumors of mesenchymal origin. They are often solitary lesions of submucosal origin found in the proximal colon and typically measure less than 2 cm in size. Giant colonic lipomas are greater than 4 cm and present with non-specific gastrointestinal symptoms such as abdominal pain, abdominal distention, constipation, or gastrointestinal bleeding. Traditionally, giant colonic lipomas have been surgically rather than endoscopically resected due to concerns for bowel wall perforation and life-threatening hemorrhage. However, in recent years, advances in endoscopic tools and hemostatic techniques have lessened these risks. The following case details the successful endoscopic resection of an intermittently obstructing giant colonic lipoma (6 cm) located in the descending colon utilizing the loop-assisted-snare resection technique. 

Sheep in Wolf's Clothing: Pedunculated Colonic Lipoma with Overlying Hyperplastic and Ulcerated Epithelium

INTRODUCTION

Lipomas are the most common non-epithelial benign tumors of the gastrointestinal tract with a reported incidence in the colon of 0.2-4.4%. These lesions are usually asymptomatic with a typical endoscopic finding of a smooth, slightly yellow, circular, polyp that is sessile in most cases, covered with normal colonic mucosa.

AREAS COVERED

There are rare reported cases of alterations of the overlying mucosa such as hyperplasia, atrophy, adenomatous changes, and necrosis.

EXPERT COMMENTARY

We report a rare case of pedunculated colonic lipoma of the transverse colon covered with hyperplastic and ulcerated epithelium easily misdiagnosed as an adenomatous lesion.

Is endoscopic resection a correct treatment for atypical gastrointestinal lipomas?

We would like offering our experience about a very rare and underestimated type of gastrointestinal lipoma, which is the lipoma with precancerous or frankly malignant features of the mucosal epithelium, the so-called atypical lipoma. So far, only few cases have been described in the world literature. Recently, we grappled with what we think the first case of atypical colonic lipoma presenting with adenocarcinomatous transformation of the overlying epithelium, as discussed in more detail below. We propose a new definition and classification for this kind of lesions and discuss about their diagnosis, treatment and prognosis.