Small Cell Carcinoma of the Rectum Associated With a Tubulovillous Adenoma: An Atypical Case Presentation

Small cell carcinoma of the rectum (SCCR) is a rare and aggressive neuroendocrine tumor. Its association with a tubulovillous adenoma is an exceptional occurrence, presenting significant implications for diagnosis and treatment. This case report details a 62-year-old male, undergoing treatment for hepatocellular carcinoma, presented with symptoms of diarrhea. A colonoscopy initially suggested a benign tubulovillous adenoma, but the presence of discordant clinical findings led to further evaluation. The final diagnosis, established post-surgery, was SCCR originating from a tubulovillous adenoma. This case highlights the diagnostic challenges when unusual presentations arise from atypical pathological findings, especially in patients with concurrent malignancies. The management followed standard care protocols, including robotic transanal surgery, despite the patient's ongoing HCC treatment. This case adds to the limited existing literature on SCCR, particularly its rare association with a tubulovillous adenoma. It emphasizes the importance of a multi-disciplinary approach in diagnosing and managing rare entities in colorectal cancer while demonstrating the feasibility of standard care in patients with complex comorbidities.

Novel laparo-endoscopic hybrid technique of management of a rare case of duodeno-duodenal intussusception

We herein report a rare case of duodeno-duodenal intussusception (IS) presenting with obstruction caused by tubulovillous adenoma in an adult with malrotation that was managed by a novel laparoendoscopic hybrid technique. This was done by passing transjejunal nasogastric tube (NG) through one of the ports and manoeuvring it towards the IS. Two hundred and fifty millilitre of saline was flushed by aseptosyringe with pressure connected to the NG. This hydrostatic reduction technique resulted in distension of the jejunal and duodenal loop achieving reduction of IS. Intraoperative endoscopy was performed to exactly localise the mass lesion. The duodenum was kocherised and was delivered through a 4-cm transverse incision. Anterior duodenotomy was performed; the mass was excised; and duodenotomy was closed transversely. An extensive literature search did not show any case report of duodenoduodenal IS being managed by this technique. The combination of novel retrograde decompression and intraoperative endoscopy helped us to manage this rare case by this novel technique.

McKittrick-Wheelock Syndrome: A Case Report

An adenoma is the most typical large bowel tumor found in 30% of all screening colonoscopies. However, it is often asymptomatic but sometimes might lead to abdominal pain or bleeding of the rectum. Critical electrolyte disbalance and acute kidney injury caused by secretory diarrhea is an untypical clinical manifestation of adenoma. It has rarely been reported in the literature and is defined as McKittrick-Wheelock syndrome. A 61-year-old patient was hospitalized for heavy dyselectrolytemia, diarrhea, acute kidney injury, sepsis, and fever. After the renal function was corrected and electrolyte imbalance persisted, visual instrumental diagnostics tests revealed a large tumor in the sigmoid colon. Subsequently, the patient underwent surgical resection, which exhibited evidence of tubulovillous adenoma on pathology. The atypical signs of McKittrick-Wheelock syndrome and comorbidities can make the diagnostics challenging. When severe hyponatremia and hypokalemia are followed by persistent mucous diarrhea, the clinicians should suspect MWS as a possible reason for it.

Initial Experience With Trans-anal Minimally Invasive Surgery (TAMIS) for Rectal Polyps and Early Colorectal Cancers at Cumberland Infirmary, Carlisle

INTRODUCTION

Bowel cancer is the fourth most common type of cancer in the United Kingdom in 2019. Total mesorectal excision is the standard procedure for the removal of rectal tumors, however, it comes with serious side effects. Therefore, less invasive procedures and sphincter preservation techniques have been developed, like conventional trans-anal excision, and trans-anal endoscopic microsurgery (TEM). In 2010, trans-anal minimally invasive surgery (TAMIS) was introduced as an alternative to TEM, which offers the same benefits as TEM but at a lower cost and without the need for specialized instrumentation. This study aims to assess the practicability and safety of this technique and to report its findings.  Methods: Retrospective data of all patients who underwent TAMIS at Cumberland Infirmary (Carlisle, UK) from July 2017 to July 2022 for large benign rectal polyps or early rectal cancer were collected. Variables collected included patients' age, gender, number of procedures per year, perioperative outcome, and histopathology outcome. The SPSS version 21 (IBM Corp., Armonk, NY, USA) was used for both descriptive and inferential analyses of the data.

RESULTS

During a five-year period, 42 patients underwent TAMIS at Cumberland Infirmary. The primary indication for TAMIS was distal rectal lesions, large rectal polyps up to 120 mm, and early rectal cancer (T1). The median age of the assessed patients at the time of surgery was 71 years with 64.29% (27) male and 35.71% (15) female. The mean operating time was 123 minutes (range 45 to 240 minutes). The surgical and pathological outcome included a mean polyp size of 6 cm (+/- 0.8 cm), a rate of specimen fragmentation at 19.04% (n=8), and a rate of positive margins at 04.76% (n=2), whereas histology of 73.81% (n=31) was tubulovillous adenoma and 11.91% (n=5) was adenocarcinoma. There was no 30-day postoperative mortality, however, the 30-day re-operation rate was 02.39% (n=1) and the recurrence rate which needed further intervention was 26.19% (n=11).

CONCLUSION

Our findings suggest that TAMIS produces positive results. The size of the lesions removed, and the effect of an early learning curve are reflected in the rate of specimen fragmentation and polyp recurrence. Nonetheless, TAMIS is a safe and effective alternative to total mesorectal excision for certain types of rectal lesions and should be used for more proximal and complex rectal lesions.

Adrenal Cortical Carcinoma and Additional Rare Pathologic Findings in Multi-Organs in a Birt-Hogg-Dubé Syndrome Patient: With an Emphasis on the Molecular Characteristics of Adrenal Cortical Carcinoma

Birt-Hogg-Dubé (BHD) syndrome is a rare autosomal dominant disorder caused by germline alterations in the FLCN gene. We report a 38-year-old man with BHD syndrome presenting with multiple rare pathologic findings involving various organs, including adrenal cortical carcinoma (ACC). Initially, he presented with severe cholestatic jaundice and was found to have a 25 cm left adrenal mass with radiologic evidence of lung metastases, which was diagnosed as ACC on resection. Concurrently, pigmented, bile-stained granular casts were present within the kidney and diffuse cholestasis of the liver consistent with Stauffer syndrome was identified. Subsequent staging workup detected a 1.2 cm tubulovillous adenoma in the distal ascending colon and an incidental 1.2 cm thyroid nodule. Germline genetic testing revealed a pathogenic FLCN c.1285dup. Targeted DNA next generation sequencing of ACC revealed FLCN c.1285dup, IDH2 c.5332C>T, PRKAR1A c.1074del, and PDGFRB c.3282C>A and concurrent transcriptomic analysis demonstrated VEGFA overexpression. Fourteen months after resection, follow-up computerized tomography (CT) identified the progression of lung metastases and chemotherapy with etoposide doxorubicin and cisplatin was initiated. Here, we report the first ACC with the molecular characteristics in a BHD syndrome patient, although 5 adrenal lesions, including ACC, adenomas or neoplasm with malignant potential due to higher Ki67 labelling index, have been reported in the literature and no somatic analysis in these tumors were performed. Despite the rarity, our case potentially expands the tumor spectrum of BHD patients, helps to solidify possible association with adrenal cortical tumors and reiterates the value of genetic counseling in patients with ACC.

McKittrick-Wheelock Syndrome: A Neoplastic Cause of Electrolyte Imbalance

The authors present the case of a 79-year-old woman who presented with chronic secretory diarrhoea and severe electrolyte imbalance. A large rectal tubulovillous adenoma was discovered, leading to surgical resection of the tumour with complete resolution of the diarrhoea and electrolyte imbalance. The diagnosis of McKittrick-Wheelock syndrome was made. We hope this case report will contribute to a greater awareness among health professionals about this clinical condition. A multidisciplinary approach is essential for the best outcome.

LEARNING POINTS

McKittrick-Wheelock syndrome is an important differential diagnosis in patients presenting with electrolyte abnormalities and secretory diarrhoea.A multidisciplinary approach from the beginning is important for a timely diagnosis and better outcome.Surgical removal of the hypersecretory villous adenoma is the definitive treatment for McKittrick-Wheelock syndrome and can be life-saving.

The Genomic Landscape of Serrated Lesion of the Colorectum: Similarities and Differences With Tubular and Tubulovillous Adenomas

Serrated lesions of the colorectum are the precursors of 15-30% of colorectal cancers (CRCs). These lesions have a peculiar morphological appearance, and they are more difficult to detect than conventional adenomatous polyps. In this study, we sought to define the genomic landscape of these lesions using high-depth targeted sequencing. Eight sessile serrated lesions without dysplasia (SSL), three sessile serrated lesions with dysplasia (SSL/D), two traditional serrated adenomas (TSA), and three tubular adenomas (TA) were retrieved from the files of the Institute of Pathology of the University Hospital Basel and from the GILAB AG, Allschwil, Switzerland. Samples were microdissected together with the matched normal counterpart, and DNA was extracted for library preparation. Library preparation was performed using the Oncomine Comprehensive Assay targeting 161 common cancer driver genes. Somatic genetic alterations were defined using state-of-the-art bioinformatic analysis. Most SSLs, as well as all SSL/Ds and TSAs, showed the classical BRAF p.V600E mutation. The BRAF-mutant TSAs showed additional alterations in CTNNB1, NF1, TP53, NRAS, PIK3CA, while TA showed a consistently different profile, with mutations in ARID1A (two cases), SMAD4, CDK12, ERBB3, and KRAS. In conclusion, our results provide evidence that SSL/D and TSA are similar in somatic mutations with the BRAF hotspot somatic mutation as a major driver of the disease. On the other hand, TAs show a different constellation of somatic mutations such as ARID1A loss of function.

Transanal minimal invasive surgery (TAMIS): safety and feasibility for the resection of benign and malignant lesions of the rectum

Objectives

Radical surgery for rectal tumours has high morbidity. Local excision of such tumours can be achieved without compromising oncologic safety. However tumours that are not accessible to local excision can be approached using Transanal Minimal Invasive Surgery (TAMIS). The aim of our study was to assess feasibility of TAMIS procedure in terms of complications, operating time, resection margin positivity, hospital stay and local recurrence rate.

Material and Methods

Forty eight patients with benign adenomas or early stage adenocarcinoma, within 4 to 12 cm from anal verge who were subjected to TAMIS over a period of 3 years were included in the study. Short and long term outcomes were assessed.

Results

TAMIS was performed for 36 benign adenomas and 12 adenocarcinomas, which were located at an average distance of 6.2 cm from anal verge. The mean operating time was 72 minutes. There were no intraoperative complications.1 (2.08%) patient suffered post operative bleeding, which was managed conservatively. 2 (4.16%) patients developed acute urinary retention who required indwelling catheterisation. Resection margin was positive in 3 (6.25%) benign cases. Average hospital stay was 2.7 days. Local recurrence occurred in 2 (4.16%) villous adenoma patients (after 11 and 13 months), whereas in malignant patients there was no recurrence at a follow up period ranging between 12 to 36 months.

Conclusion

TAMIS is a safe and feasible procedure for benign tumours and early rectal cancers, located in low and middle rectum.

Tiny but Mighty: Collision Tumor of a Superficial Adenocarcinoma Arising From a Tubulovillous Adenoma with Associated Low-Grade Follicular Lymphoma

Collision tumors are rare and there have only been a few previously described cases between an intestinal adenoma and a lymphoma. We report the first case of a 74-year-old woman who on investigation for iron deficiency had a tubulovillous adenoma with underlying follicular lymphoma. The atypical lymphoid proliferation showed immunohistochemical positivity for cluster of differentiation 20 (CD20), B-cell lymphoma 2 (BCL2), and B-cell lymphoma 6 (BCL6). Subsequent right hemicolectomy showed a superficially invasive adenocarcinoma.

McKittrick-Wheelock Syndrome: A Rare Cause of Chronic Diarrhea

Diarrhea is the principal cause of the majority of healthcare utilization. When diarrhea lasts longer than four weeks, it is considered chronic diarrhea. There are several causes of chronic diarrhea, but here we focus on one of the rare causes, known as McKittrick-Wheelock syndrome (MWS). We here present the case of a patient in his seventies with chronic diarrhea, found to have tubulovillous adenoma and diagnosed with McKittrick-Wheelock syndrome. We also discuss the clinical presentation, pathophysiology, and management of MWS.

Differential diagnosis of traditional serrated adenomas and tubulovillous adenomas: a compartmental morphologic and immunohistochemical analysis

AIM

Traditional serrated adenomas are the rarest member of the serrated polyps, that have endoscopic and morphologic similarities with conventional adenomas, tubulovillous adenomas, in particular. We aimed to compare the histopathologic and immunohistochemical features of TSAs showing overt dysplasia with conventional TVAs in a compartmental manner using digitalized images.

PATIENTS AND METHODS

For 25 TSAs and 25 TVAs, extent of the morphologic features including cytoplasmic eosinophilia, mid-zonal nuclei, ECFs, slit-like serration, brush border, gastric foveolar-like epithelium and goblet cells were evaluated. Immunohistochemistry was perfomed using primary antibodies including CK7, CK20, MUC2, MUC5AC, MUC6, B-catenin, Ki67, p53, p16, MLH1, MSH2, MSH6 and PMS2.

RESULTS

Eosinophilic cells, mid-zonal nuclei, slit-like serration and ECF were significantly more extensive in TSAs compared to TVAs (p<0,001) while gastric epithelium was also more extensive in TSA cohort with a lower significance (p<0,01). Cut-offs for these features yielding the highest sensitivity and specificity in discriminating TSAs from TVAs were determined ; mid-zonal nucleus resulted as the best discriminating histopathologic feature (100%, 92%) followed by eosinophilia (88%, 92%),and slit-like serration (84%, 92%) with highest sensitivity and specificities, respectively. Compartmental immunohistochemical evaluation revealed that CK20 and CK7 were mainly expressed in ECF while MUC5AC together with CK7 were found in epithelial compartment more frequently in TSAs compared to TVAs. P16 was more common in TSAs in all compartments whereas Ki67 and p53 were restricted to dysplastic compartments in both polyp groups.

CONCLUSIONS

The present study demonstrated that mid-zonal nuclei, eosinophilic cells and slit-like serration followed by ECF proved to be the most discriminatory features for TSAs.The correct diagnosis of TSAs will allow to develop appropriate treatment and follow up modalities which seem to be crucial as their progression rate may be different from TVAs.

Endoscopic Management of a Tubulovillous Adenoma Within a Diverticulum: Report of a Case and Review of Literature

Adenomas or adenocarcinomas located within a colonic diverticulum are considered a rare phenomenon that has been described in the literature. These lesions are technically difficult to manage endoscopically and usually require surgical intervention for removal. There is also an increased risk of perforation upon endoscopic resection owing to the lack of a muscular layer within the diverticulum. We report a case and include a literature review to evaluate different endoscopic techniques and propose the most effective for management of adenomas within a diverticulum. This technique is potentially comprised of employing a combined approach using a suction banding device, an over-the-scope clip (OTSC; Ovesco Endoscopy AG, Tübingen, Germany) , and hyperthemic snare to successfully remove the polyp, ensure tissue retrieval, and reduce risk of iatrogenic colonic perforation.

Tubulovillous Adenoma in the Bladder in a Dual Pancreas-Kidney Transplant Patient

Background: A rare report of a tubulovillous adenoma arising in the setting of a dual pancreas-kidney transplant patient.

Case Presentation: This adenoma was discovered in a 60-year-old male with a dual pancreas-kidney transplant that presented with urinary retention and gross hematuria. Management of this patient required both transurethral resection of the tumor as well as a laparotomy after recurrence. Follow-up with cystoscopy has shown no further recurrence of the tumor.

Conclusion: This case adds to the few cases documented of adenomas arising in bladders augmented with gastrointestinal tract tissue. The tumor may reflect growth from donor duodenal graft tissue, however, the metaplasia of urothelial tissue cannot be fully ruled out. Based on this case, our understanding of these rare tumors and their clinical course is deepened.

Serrated tubulovillous adenoma of the large intestine

AIMS

Most colorectal polyps are classified readily, but a subset of tubulovillous adenomas (TVA) with prominent serrated architecture causes diagnostic confusion. We aimed to (i) identify histological features that separate serrated TVAs from both conventional TVAs and traditional serrated adenomas (TSA) and (ii) perform a clinicopathological and molecular analysis to determine if the serrated TVA has unique features.

METHODS AND RESULTS

We collected 48 serrated TVAs, 50 conventional TVAs and 66 BRAF wild-type TSAs for analysis. For each polyp we performed a clinicopathological assessment, BRAF and KRAS mutation profiling, cytosine-phosphate-guanosine (CpG) island methylator phenotype status, MGMT methylation and immunohistochemical assessment of seven markers [MutL homologue 1 (MLH1), p16, p53, β-catenin, Ki67, CK7 and CK20]. We found that serrated TVAs can be diagnosed reliably, and have features distinct from both conventional TVAs and TSAs. Compared to conventional TVAs, serrated TVAs are larger, more often proximal, more histologically advanced, show more CpG island methylation and more frequent KRAS mutation. Compared to TSAs they are more often proximal, show less CpG island methylation, more frequent MGMT methylation and more frequent nuclear staining for β-catenin.

CONCLUSIONS

The serrated TVA can be diagnosed reliably and has unique features. It represents a precursor of KRAS mutated, microsatellite stable colorectal carcinoma.

KRAS gene mutations are more common in colorectal villous adenomas and in situ carcinomas than in carcinomas

We have evaluated the frequency of KRAS gene mutations during the critical transition from villous adenoma to colorectal carcinoma to assess whether the adenomas contain a KRAS mutation more frequently than carcinomas. We analyzed sporadic villous and tubulovillous adenomas, in situ carcinomas, and primary colorectal carcinomas from multiple patients. The cancers were further evaluated for mucinous status and microsatellite instability. Standard PCR molecular techniques were used for KRAS and microsatellite analyses. A KRAS mutation was found in 61.9% of 134 adenomas, 67.8% of 84 in situ carcinomas, and just 31.6% of 171 carcinomas. Our study clearly demonstrates that tubulovillous and villous adenomas, as well as both the benign and malignant parts of in situ carcinomas, are statistically more likely to contain a somatic KRAS gene mutation than colorectal carcinomas. This difference is confined to the non-mucinous and the microsatellite stable tumors. Our data support the possibility that non-mucinous and microsatellite stable carcinomas with wild-type KRAS gene may have had a mutation in the KRAS gene during their earlier stages, with the mutation lost during further growth.

Laparoscopic antrectomy for a proximal duodenal Brunner gland hamartoma

BACKGROUND

Adenoma is the most common cause of duodenal polyps, while hamartomas are very rare. We present a patient with a preoperative histology proved diagnosis of isolated duodenal tubulovillous adenomatous polyp with high-grade dysplasia for whom we performed laparoscopic antrectomy.

CASE REPORT

The patient was a 56-year-old male with vague upper abdominal pain. Investigations revealed a 3-cm x 3-cm mass arising from the duodenal mucosa with no evidence of extraserosal spread. Histopathology documented an adenomatous polyp with high-grade dysplasia, so a laparoscopic antrectomy was performed.

RESULTS

The patient had an uneventful postoperative period, requiring only 2 doses of parenteral analgesics. He was discharged on the seventh postoperative day. The final histopathological findings were consistent with benign hamartoma. No recurrence has been reported after 14 months of follow-up with endoscopy.

DISCUSSION

Many procedures have been described for polyps, such as endoscopic excision, duodenectomy, pancreatoduodenectomy, and laparoscopic polyp excision. In our patient, the decision to perform duodenectomy was based on the preoperative findings of a sessile tubulovillous adenomatous polyp with high-grade dysplasia. Histologically, the 2 entities can be identical, especially with the small tissue volume obtained from endoscopic biopsy.

CONCLUSION

Given these observations, antrectomy was probably ideal, because endoscopic excision would have been inadequate and even dangerous while pancreatoduodenectomy would have been too radical.