Clear cell change in colorectal adenomas: its incidence and histological characteristics

Mucinous Adenocarcinoma of the Colon with Clear Cell Component: A Case Report and Literature Review

Clear cell adenocarcinomas of the colon are defined as a subtype of colorectal adenocarcinoma with clear cell morphology. A 65-year old man was admitted to a Gastroenterology Department for diagnostic evaluation of a tumor in the sigmoid colon found on CT. There, the patient developed complete bowel obstruction and was operated urgently, where intraoperatively, a large tumor in the sigmoid fixated to the lateral abdominal wall was revealed. A subtotal colectomy was performed. Histopathological analysis of the surgical specimen was conducted. The immunohistochemistry staining was positive for CEA, CDX2, and CD20 and negative for CK7, CD10, MUC2, AFP, and PAS staining. Mismatch repair protein testing was negative. The pathological diagnosis was mucinous carcinoma with a clear cell component which bears an extremely low incidence that has been scarcely reported in literature. This stresses the need for more case reports like ours to be published.

The histomorphological and molecular landscape of colorectal adenomas and serrated lesions

The 2019 WHO classification of digestive system tumors significantly reformed the classificatory definition of serrated lesions of the colorectal mucosa and added new essential diagnostic criteria for both conventional adenomas and hereditary gastrointestinal polyposis syndromes. Histopathological examination of colorectal adenocarcinoma precursors lesions represents an important segment of daily clinical practice in a pathology department and is essential for the implementation of current colorectal adenocarcinoma secondary prevention strategies. This overview will focus on a schematic histopathological and molecular classification of precursor lesions arising within colorectal mucosa.

Early stage clear cell adenocarcinoma coexisting with tubular adenoma and adenoma with clear cell change in the colon

Primary clear cell adenocarcinoma (CCA) of the colorectum is rare. We report a case of a 57-year-old man with early-stage CCA with conventional tubular adenoma and tubular adenoma with clear cell change in the transverse colon, diagnosed with image-enhanced endoscopy. The tumor was then treated with endoscopic submucosal dissection. The endoscopic findings characteristic of clear cell adenoma/adenocarcinoma could not be identified. Therefore, similar diagnostic tools as for conventional colorectal adenoma/cancer were considered. The pathogenesis of the clear cell change was unknown, but it might appear with the progression of the malignancy.

Incidental morphological findings in colorectal adenomas

Owing to a sharp increase in the frequency of diagnosis of colorectal adenomas in the current era of population screening, distinctive morphological features are increasingly being observed. These may present diagnostic challenges and cause clinical management issues. Paneth cell metaplasia is a more common occurrence, but the incidence rates of squamous metaplasia, clear cell metaplasia, osseous metaplasia, neuroendocrine differentiation and signet‐ring cell‐like lesion are low, and they can be seen in <1% of colorectal adenomas. Their histomorphological characteristics are quite unique; ancillary studies are not very helpful and often not needed. In this review, we give an overview and describe the potential clinical consequences of such incidental and special morphological findings in colorectal adenomas.

Colon adenoma and adenocarcinoma with clear cell components - two case reports

Background

Diagnoses reflect clear cell morphologies when tumor cells have clear cytoplasm in many organs, and the nature of such clear cells is typically identified. Colorectal tubular adenoma or adenocarcinoma, conversely, rarely show clear cells, the reason for which remains uncertain. We report 2 colon tumors with clear cell components (Case 1: adenoma; Case 2: adenocarcinoma) and investigate the nature of the clear cells.

Case presentation

Case 1 was a 75-year-old man with a superficial elevated polyp detected in the rectum for whom endoscopic submucosal dissection was performed. Microscopically, 10% of the tumor showed dysplastic columnar epithelium with clear cytoplasm forming tubular structures accompanied by conventional tubular adenoma. Case 2 was a 58-year-old man with a pedunculated polyp found in his sigmoid colon for which polypectomy was performed. Microscopically, 90% of the tumor showed dysplastic columnar epithelium with clear cytoplasm forming fused glands or cribriform structures adjacent to the ordinal tubular adenocarcinoma. In both cases, clear and ordinary tumor cells were negative for CK7 and positive for CK20 and CDX2, consistent with findings of colorectal origin. Different results were found for CEA and CD10 staining. CEA was positive on the luminal side of the conventional area in contrast diffuse cytoplasmic staining of the clear cell area in both cases. CD10 was only positive for the clear cell component of case 2. The clear cell components were negative for Periodic acid-Schiff (PAS), Alcian blue, and mucicarmine staining and AFP immunohistochemistry. An ultrastructural examination found multiple cytoplasmic lipid-like vacuoles in the clear cell component that were predominantly negative for adipophilin by immunoelectron microscopy.

Conclusions

We investigated tubular adenoma and tubular adenocarcinoma with clear cell components. The accompanying conventional tubular adenoma or adenocarcinoma cells helped us to evaluate the atypia of the clear cells. Diffuse cytoplasmic staining of CEA and CD10 suggested that the clear cell component might harbor malignant potential. We were unable to verify the well-known causes of clear cytoplasm, such as an accumulation of glycogen, lipid, or mucin and enteroblastic differentiation. The causes of clear cells in the colorectal region remain uncertain; however, possible explanations include autolysis and carbohydrate elution.

Diagnostic and reporting issues of preneoplastic polyps of the large intestine with early carcinoma

Premalignant polyps of the large intestine are common specimens in surgical pathology. They consist of several different subtypes identifiable by histological criteria that are associated with different molecular characteristics and with the development of different types of colorectal carcinoma. The most common of these is the conventional adenoma, which most commonly leads to carcinomas with a low degree of methylation (CIMP-L) that are microsatellite stable. In Lynch syndrome patients these polyps lead to CIMP-L carcinomas that are microsatellite instable. The second most common is the sessile serrated adenoma, which leads to carcinomas with a high degree of methylation (CIMP-H) that may be either microsatellite stable or instable. The least common premalignant polyp is the traditional serrated adenoma, which can lead to either CIMP-L or CIMP-H carcinomas, most often microsatellite stable. This paper will review the histological features of these lesions, discuss problems in diagnosis and discuss the role of histology in management.

Successful management of perivascular epithelioid cell tumor of the rectum with recurrent liver metastases: A case report

RATIONALE

The perivascular epithelioid cell tumor (PEComa) is rare in young man and rarely occurs in the large intestine.

PATIENT CONCERNS

The clinical characteristics, diagnosis, and managements in a 28-year-old boy who presented with sudden onset of cramping and abdominal pain and intermittent melena with a blood pressure of 74/39 mm Hg was retrospectively reviewed. CT scan of the abdomen revealed a 8.9 × 7.2 cm mass in the pelvic floor.

DIAGNOSES

Given the difficulty of obtaining a diagnostic specimen, surgical resection was performed. The pathology report of lower anterior resection was malignant PEComa of the rectum in 2006.

INTERVENTIONS

Treatment consisted of surgical resection only without additional adjuvant therapy. Over the next 49 months (until 2010) after surgery, abdominal CT showed a 0.6-cm hypodense mass over the liver with suspected liver metastasis. He refused any further evaluation and treatment. After 4 years (2014), abdominal CT showed that the original mass had increased from 0.6 to 1.5 cm and the number of tumors had increased from 1 to 3. In August 2014, he underwent a metastatic hepatectomy without additional chemotherapy or radiotherapy.

OUTCOMES

We noted that the metastatic progression was slow in the 4 years after the first operation. At 28 months after metastatic hepatectomy, the patient was doing well. There was also no recurrence of the PEComa of the rectum at the 120-month follow-up in 2016.

LESSONS

To the best of our knowledge, this is the first report of a PEComa of the rectum with liver metastases treated with only surgical resection. At approximately 8.8 cm, this is the largest PEComa of the rectum reported in the recent literature.

Early stage clear cell adenocarcinoma of the colon examined in detail with image-enhanced endoscopy: a case report

Primary clear cell adenocarcinoma (CCA) of the colorectum is a rare tumor. We report on a 48-year-old man with early stage CCA in the descending colon who underwent detailed examination with image-enhanced endoscopy, such as magnifying endoscopy with narrow-band imaging and crystal violet staining. The tumor was treated successfully with endoscopic mucosal resection at our hospital.

Colonic wall changes in patients with diverticular disease - is there a predisposition for a complicated course?

BACKGROUND

The aim of this study was to evaluate colonic wall changes and enteric neuropathy in patients with either uncomplicated (UDD) or complicated diverticular disease (CDD). Furthermore, we evaluated the presence of an anatomic sphincter at the rectosigmoid junction (RSJ).

METHODS

Samples of colonic tissue from fifteen patients with UDD, fifteen patients with CDD and fifteen patients as control were collected. Collagen quotient I/III was measured with the Sirius-red test, expression of MMP-1, MMP-13, innervation (S100), proliferation (Ki67) and apoptosis (TUNEL) in the colonic wall were investigated by immunohistochemical studies. Furthermore, measurements of the different layers were performed to investigate the RSJ.

RESULTS

Patients with either UDD or CDD had lower collagen I/III quotients compared to the control group, significant for CDD (p = 0.007). For MMP-1 and MMP-13 only a slight increase for patients with CDD was found. The percentage of proliferating (Ki67) and apoptotic (TUNEL) cells was significantly higher for patients with CDD than in the control group (p = 0.016; p = 0.037). Upon investigating the S100-expression a significant reduce in glial cells density was found in the myenteric and mucosal plexus for both groups (UDD and CDD) compared to the control group. Measurements of the different colon layers oral, aboral and at the RSJ revealed equal values.

CONCLUSIONS

This study has shown that colonic wall changes and enteric neuropathy seem to play a role in the pathogenesis of colonic diverticulosis. None of our results suggest a predisposition for a complicated diverticular disease. Furthermore, the presence of an anatomic sphincter at the rectosigmoid junction could not be detected.

Clear cell adenocarcinoma of the colon: a case report and review of the literature

Clear cell adenocarcinoma of the colon has been described scarcely in the literature. It affects elderly men more commonly than women and usually appears in the left side of the colon. A Hispanic 41-year-old female came to the emergency room with abdominal pain, vomiting, and distension. Physical exam revealed generalized tenderness without peritoneal signs. Laboratory data was unremarkable. A CT scan showed an apple-core lesion in the distal colon. A flexible sigmoidoscopy revealed an obstructive mass that made further evaluation impossible. Exploratory surgery revealed a hard mass obstructing the descending colon, which was resected. Histopathology analysis with immunohistochemistry staining was positive for cytokeratin 20, cytokeratin 10, CDX2, and villin, while it was negative for cytokeratin 7, RCC, vimentin, and CD31. These results confirmed the clear cell variant of the adenocarcinoma. Clear cell adenocarcinomas usually arise from the kidneys and Müllerian organs. Immunohistochemistry is crucial for establishing the origin of these neoplastic cells. A cytokeratin 20+/7− with positive CDX2 is highly specific and sensitive for intestinal neoplastic origin. The main treatment has been surgery alone with moderately good results. More research and information about this malignancy is needed, especially in regard to prognosis and in order to provide the best treatment option.

Clear cell change in colonic tubular adenoma and corresponding colonic clear cell adenocarcinoma is associated with an altered mucin core protein profile

Clear cell change is seen in <1% of colonic tubular adenomas (TAs) and remains incompletely characterized. Associated adenocarcinomas can also demonstrate a clear cell phenotype. Eleven TAs with at least focal clear cell change with or without associated invasive adenocarcinoma, from 10 patients were studied. The lesions were stained with periodic acid-Schiff (PAS)/PAS-diastase and immunolabeled with antibodies to MUC2, MUC5AC, MUC6, CK7, CK20, and CDX2. Eight of 11 (77%) TAs with clear cell change had focal to extensive high-grade dysplasia. Two were associated with invasive clear cell adenocarcinoma. The adenomas and adenocarcinomas ranged from 0.5 to 3.5 cm. PAS/PAS-diastase stains showed minimal PAS(+) material in the clear cells. On immunohistochemical studies, the clear cells had decreased MUC2 labeling compared with the surrounding conventional adenoma in 9 of 11 (88%) cases, including the 2 clear cell adenocarcinomas. In 3 of the 11 lesions, the background TA showed at least focal MUC5 immunoreactivity, their associated clear cell area had decreased MUC5 labeling in all 3 cases. No immunoreactivity to MUC6 was observed in the background TAs and clear cells in all cases. Compared with background TA, both increased and decreased expression of CK7, CK20 (in quantity), and CDX2 (in intensity) were observed in the clear cells of TAs and adenocarcinomas. One of the clear cell adenocarcinomas was CK20, CK7, CDX2 and the other was CK20, CK7, CDX2-focal positive. Thus, although the clear cells have different MUC protein profiles than the background adenomatous epithelium, invasive clear cell adenocarcinomas retained the typical CK20(+)/CK7(-) profile of conventional adenocarcinomas. Our results indicate that clear cell adenocarcinomas can be primary to the colorectum with identifiable precursors. Awareness of them and their immunoprofile allows distinction from clear cell lesions from other sites.

Perivascular epithelioid cell neoplasm of the colon

A 17-year-old female presented with rectal bleeding from an ulcerated sigmoid mass in 1994. Initial pathological evaluation revealed a rare clear cell neoplasm of the colon, possibly originating from kidneys, adrenals, lung or a gynecologic source as a metastatic lesion. Extensive imaging studies were negative, and over the next 15 years, she remained well with no recurrence. The original resected neoplasm was reviewed and re-classified as a perivascular epithelioid cell neoplasm (PEComa). Although the long-term natural history of PEComas requires definition, increased clinical and pathological awareness should lead to increased recognition of an apparently rare type of colonic neoplasm that likely occurs more often than is currently appreciated.

Clear cell adenocarcinoma of the colon is a unique morphological variant of intestinal carcinoma: Case report with molecular analysis

Here we report a new case of clear cell adenocarcinoma (CCA) of the colon in a 54-year-old Caucasian man. Despite of the previous reported cases, the lesion was located in the right colon and was not associated with the conventional adenoma. We performed immunohistochemical and molecular analyses in order to explore whether the CCA had the molecular features generally associated with conventional colorectal carcinoma. The immunohistochemical and molecular analyses showed that the different morphology of CCA does not reflect a distinct biological entity but only an unusual morphological variant of intestinal carcinoma.

Clear cell change in colonic polyps

In this study, the pathogenesis of clear cell change in colorectal epithelial lesions was studied. A total of 4 cases of clear cell change (1 hyperplasic polyp and 3 adenomas) were characterized using histochemistry, immunohistochemistry, and electron microscopy. All lesions developed in the left colon. In all, 1 adenoma with clear cell dysplastic glands progressed to adenocarcinoma without clear cell change. Clear cell cytoplasmatic vacuoles were negative for glycogen and mucins (MUC 2, MUC 5AC). Ki-67 LI in clear cell adenoma components was lower than in common adenoma components of the same dysplasia grades (while p53 and beta-catenin were similarly expressed). Ultrastructural features of clear cell change showed features of lipid-like material. Clear cell change is found in hyperplastic and neoplastic lesions of the colon and is not due to the accumulation of glycogen or mucins. A degenerative nature of clear cell change is suggested by the demonstration of lipid-like material in the vacuoles of clear cells.

Invasive carcinoma arising from a colonic adenoma with clear cell change

Clear cell change (CCC) in colonic adenoma is rare, and its biological and clinical significance remains unknown. Malignant progression of an adenoma with CCC has seldom been reported. We report a case of a sigmoid adenoma with multiple foci of CCC associated with high-grade dysplasia and invasive carcinoma in a 62-year-old patient. We evaluated the histochemical and immunohistochemical characteristics of each component of the adenoma. In contrast to other parts of the adenoma, p53 was strongly and diffusely overexpressed in the areas of CCC, high-grade dysplasia, and carcinoma. The MIB-1 labeling index was also significantly higher in these components than in other parts of the adenoma. In conclusion, our findings suggest that CCC in adenoma may be associated with malignant progression of the adenoma. Hence, for practical purposes, we recommend considering CCC in colonic adenomas as a high-grade dysplasia equivalent and following up the patient accordingly.

Clear cell adenocarcinoma of the colon: A case report and review of literature

A primary clear cell adenocarcinoma of the colon is a rare oncologic entity. We herein report a case of such a tumor of the sigmoid colon in a 71-year-old woman who was successfully treated by an endoscopic polypectomy in our hospital. We also reviewed the published reports regarding cases of primary clear cell tumors in the colon.

The clear cell adenocarcinoma of the colon: case report and review of the literature

BACKGROUND

Primary clear cell adenocarcinoma of the colon is a rare oncological entity. We report a case of such a tumor in the left colonic flexure of an 89-year-old patient who was treated surgically in our Department. We also review published cases which include primary colonic clear cell formations.

CASE PRESENTATION

The patient sustained a segmental resection of the region [pT2 N0 (0/12) M0]. Histochemical examination indicated a primary clear cell colonic adenocarcinoma. The patient was discharged in good health but died from his disease 2 years later.

RESULTS

Primary clear cell colonic adenocarcinoma is found exclusively in the left colon and generally in elderly men. From the few cases that have been published it is not possible to estimate the oncological impact of this tissue.

CONCLUSION

Even in advanced age surgical resection is the mainstay of the recommended treatment.

Malgun (clear) cell change in Helicobacter pylori gastritis reflects epithelial genomic damage and repair

Cancers may develop in the background of genomic instability with accumulated mutations. Helicobacter pylori gastritis is characterized by acute foveolitis of the proliferative zone, which is found in any stage of the gastritis as long as the infection persists. Because acute foveolitis targets specifically the proliferative zone of pits, the proliferating epithelial cells are under severe and persistent mutagenic pressure. In H. pylori gastritis, a characteristic morphological change of epithelial cells, the malgun (clear) cell change is frequently present in association with acute foveolitis. Malgun cells have enlarged euchromatic nuclei and abundant cytoplasm. The expression of proliferating cell nuclear antigen and cytokeratin 8 are typically up-regulated in them indicating that they are mitotically and metabolically active. Here, we report evidence for DNA damage and repair in malgun cells. Significant double-strand DNA breaks were shown by the consistent terminal dUTP nick-end labeling in the nuclei of malgun cells. Proteins related to DNA damage and repair, such as Ku, poly(ADP-ribosyl) polymerase, OGG1, and MSH2 were selectively up-regulated in malgun cells. Inducible nitric oxide synthase was also up-regulated. There were occasional bcl2- and p53-expressing cells suggesting that further steps of carcinogenesis took place at the single cell level. Our results suggest that the malgun cell change represents a characteristic morphological sign of cellular genomic damage and repair, and may be implicated in an early stage of carcinogenesis. It is suggested that acute foveolitis of the proliferative zone is a major pathogenetic step of gastric carcinogenesis in H. pylori gastritis.

"Malgun" (clear) cell change of gastric epithelium in chronic Helicobacter pylori gastritis

To characterize the Helicobacter pylori gastritis-associated epithelial change, we analyzed 251 randomly selected gastric biopsies. The "malgun" (clear) cell change of the gastric epithelium was noted in 229 biopsies (91.2%). Malgun cells were characterized by large, pale nuclei with a euchromatin pattern, enlarged nucleoli, and clear cytoplasm. In the proliferative zone, individual malgun cells and small clusters were often in close contact with infiltrating neutrophils, suggesting that they had developed individually in the background of acute foveolitis. Mitotic figures of malgun cells were not infrequent, including atypical ones. In the surface epithelium, most malgun cells were in clusters that were often large enough to occupy wide epithelial segments. With Warthin-Starry triple staining, they were distinguished by the absence of silver impregnation, while other cells showed staining of the heterochromatin. They displayed prominent immunostaining for low molecular weight cytokeratin (No. 8). Most malgun cells were PCNA-positive in both surface and proliferative zones, whereas Ki67-positive cells were found only in the proliferative zone. It was suggested that a population of malgun cells, which were positive for PCNA only, were in the process of active DNA repair. The malgun cell change may represent a "cellular pattern of activation" in a population which had significant DNA damage, but somehow escaped the detection by the apoptosis system. The notion of "damage at the genetic level" was supported by the observation that these cells remained at least for 8 weeks after eradication of the H. pylori infection.