Rectosigmoid adenocarcinoma revealed by metastatic anal fistula. The visible part of the iceberg: a report of two cases with literature review

Colon Adenocarcinoma Metastasis Through Ileocolic Fistula to Small Bowel in the Setting of Crohn's Disease

Patients with Crohn's disease are at higher risk of developing colorectal cancer and gastrointestinal fistula. Few cases in the past described colorectal cancer metastasized within the gastrointestinal tract through a fistula. We report a case of sigmoid colon adenocarcinoma in a patient with Crohn's disease that metastasized to the ileum through an ileocolic fistula tract. In addition to presenting a unique pathological phenomenon in these patients, this case raises awareness of the importance of regular follow-up and early initiation of inflammatory bowel disease therapies.

Anal Adenocarcinoma Arising From a Fistula-in-Ano: A Case Report

Crohn's disease (CD) is an inflammatory disease that can affect any portion of the gastrointestinal tract (GIT). Although it can present with a number of complications, perianal fistulae are among the most common consequences in patients with CD. In very rare cases, these patients can develop fistula-associated anal adenocarcinoma (FAAA). In this case report, we discuss a 72-year-old man with a long-term history of CD complicated by perianal fistulae, which failed medical and surgical management, ultimately presenting with acute anal pain in the outpatient setting. The physical examination revealed a seton traversing through a fistula surrounded by circumferential granulation tissue suspicious for malignancy. A biopsy of the tissue confirmed grade 3 mucinous-type infiltrating adenocarcinoma of the perianal skin. The patient was diagnosed with an anal verge malignancy associated with a fistula in the context of long-standing CD, and MRI staging demonstrated a T3N1 lesion with potential left inguinal node involvement. He completed neoadjuvant chemo-radiotherapy using capecitabine for five weeks with minimal tumor response, and subsequently, an abdominoperineal resection (APR) was performed with patient discharge on the fifth post-procedure day. Post-operative chemotherapy with oxaliplatin/leucovorin/fluorouracil was administered with minimal complications. Although rare, this report demonstrates the importance of consistent follow-up and mitigation of risk factors in patients with CD, along with the significance of prompt multimodal treatment in the event of developing FAAA.

Non-mucinous adenocarcinomas and squamous cell carcinomas of the anal region masquerading as abscess or fistula: a retrospective analysis and systematic review of literature

PURPOSE

Abscess or fistula of the anal region is an uncommon presentation of malignancy. Under the assumption of a benign condition, diagnostics is often delayed, resulting in advanced tumour stages at first diagnosis. Due to the case rarity, treatment guidelines for cancers of anorectal region masquerading as abscess or fistula are missing.

METHODS

We analysed all patients presenting with an abscess or fistula of the anal region in our department between January 2004 and August 2020. The malignancies were included to our study to acquire data on clinical presentation, treatment and outcome. Furthermore, a systematic review to present adenocarcinomas and squamous cell carcinomas associated to an abscess or fistula was performed.

RESULTS

0.5% of the patients treated for an abscess or fistula of the anal region met the selection criteria. Mean time from the onset of symptoms to diagnosis of malignancy was 100 days. Histology revealed adenocarcinoma and squamous cell carcinoma each in two patients. All patients had locally advanced tumours without distant metastases, in two cases with regional lymph-node metastases. Neoadjuvant chemoradiation was applied in two patients. All patients underwent abdomino-perineal resection of the rectum. The overall outcome reveals a recurrence-free survival of 4.5 and 3 years for two patients. Further two patients died within 5 months after the primary resection.

CONCLUSION

Advanced carcinomas of the anorectal region may masquerade as abscess or fistula, cause diagnostic problems and delay oncologic treatment. However, even in these very advanced situations, surgical therapy with curative intent should be attempted.

Recurrence of sigmoid colon cancer–derived anal metastasis: A case report and review of literature

BACKGROUND

Distant metastasis of colorectal cancer to the anus is very rare, with only 30 related cases published in PubMed thus far. Therefore, recurrence of colorectal cancer derived anus metastases is rarely seen and less presented.

CASE SUMMARY

Here we report an 80-year-old male patient who underwent radical resection for sigmoid colon cancer in January 2010 and another surgery for anal fistula resection in December 2010. Postoperative pathology of the anal fistula revealed a metastatic moderately differentiated adenocarcinoma. The patient subsequently received chemotherapy and radiotherapy. In May 2020, after the patient reported symptoms of anal swelling and pain, computed tomography and magnetic resonance imaging revealed a perianal abscess. Perianal mass biopsy was performed, and the postoperative pathological diagnosis was metastatic moderately differentiated adenocarcinoma.

CONCLUSION

This case highlights that there is a risk of recurrence of anal metastasis of colorectal cancer even after 10 years of follow-up. We also reviewed the literature and discuss potential mechanisms for anal metastasis of colorectal cancer, thus providing some suggestions for treatment of these cases.

Rectal Cancer Metastasis to the Anal Verge: An Unusual Case Presentation and Review of the Literature

Background

Anal metastasis of colorectal adenocarcinoma is very rare, represented by only a handful of case reports in the literature. Previously, reports of metastasis to this region had occurred following a history of anorectal disease, such as anal fistulae. Antecedent trauma to the area from hemorrhoidectomy, fissures, or perineal retractor injury have also been implicated.

Case Presentation

Herein we report the case of 69-year-old man without any history of anal disease presenting with a metachronous metastasis of a colorectal-type adenocarcinoma to the anal verge. He was previously treated for T1N0 rectal adenocarcinoma at the rectosigmoid junction with a low anterior resection 5 years prior, then had a T3N0 local recurrence at the colorectal anastomosis treated with neoadjuvant chemoradiation, and eventually a Hartmann's procedure 4 years later. Subsequently, on surveillance flexible sigmoidoscopy, a new tumor was identified on the perianal skin extending from the anal verge. Histopathology demonstrated colorectal-type adenocarcinoma. Flexible endoscopy identified no other residual or recurrent disease in the colon or rectal stump. The patient was treated with wide local excision and advancement flap reconstruction.

Conclusion

Isolated metastasis to the anus is an extremely rare occurrence for colorectal adenocarcinoma. There exists little evidence to inform management. One option is to treat like a locally recurrent rectal cancer with aggressive tri-modality management consisting of chemoradiation, abdominal perineal resection, and adjuvant chemotherapy. In the absence of metastatic disease, local resection and close surveillance remain an option. As always, patient factors should guide management.

Neoadjuvant chemoradiotherapy for locally advanced rectal cancer with peritumoral abscesses and fistulas

PURPOSE

Rectal cancer patients who present with peritumoral abscesses and fistulas at the time of diagnosis may be denied chemoradiotherapy (CRT) as the safety is unknown. The aim of this study was to investigate the safety of preoperative CRT in this patient group.

METHODS

We performed a retrospective nested case-control study to compare outcomes between patients with locally advanced rectal cancer with peritumoral abscesses and fistulas (study group) and patients with T4 locally advanced rectal cancer with no evidence of abscesses and fistulas (control group). These groups were matched by treatment center and radiotherapy delivery method. All patients received 50-54 Gy of conventionally fractionated RT with concurrent chemotherapy. Primary endpoint was grade 3-5 toxicity (by National Cancer Institute Common Toxicity Criteria for Adverse Events (NCI CTCAE). Secondary endpoints included postoperative morbidity, pathologic complete response (pCR), disease-free survival (DFS), and overall survival (OS) at 2 years.

RESULTS

A total of 33 patients were included in each group. Grade 3 toxicity was observed in 2 (6.1%) patients in the study group and 4 (12.1%) patients in the control group (p = 0.672). No patients developed grade 4-5 toxicity. Grade 3-4 Clavien-Dindo complications were observed in 5 (15.2%) patients in the study group and in 6 (18.2%) patients in the control group (p = 1.0). Pathologic CR was achieved in 3 (9.1%) and 5 (15.2%) patients, respectively (p = 0.708). Two-year OS was 78.3% vs. 81.8% (p = 0.944), 2‑year DFS was 62.8% vs. 69.7% (p = 0.693), respectively.

CONCLUSION

The presence of peritumoral abscesses and fistulas in patients with locally advanced rectal cancer is not associated with increased toxicity or inferior clinical outcomes after preoperative CRT.

Endoluminal tumor implant of a colorectal cancer in an anal fistula detected by FISH techniques: a case report

Intraluminal shedding of tumor cells is a rare infrequent sporadic colorectal cancer (sCRC) mechanism of spreading. Less than 30 cases of sCRC metastasis into anal fistula have been reported. Here, we study a 72-year-old male with an adenocarcinoma arising in an anal fistula. Subsequent studies revealed another tumor in the rectum without distant metastatic disease; therefore, a curative-intent abdominoperineal resection was performed. The histologic study showed a moderately differentiated adenocarcinoma in both locations. No perineural or lymphovascular invasion was observed, and all the lymphatic nodes resected were negative for malignancy. Both tumors showed positive CK20 and negative CK7 immunostaining, but KRAS G12D mutation was only detected in the rectal tumor. After those conventional studies, a cytogenetic profile of both tumors was performed by interphase fluorescence in situ hybridization (iFISH) techniques. The FISH study displayed an identical genetic profile in both tumors, loss of the chromosomes 8 and 18q, and no alteration in chromosome 7 and 13q. Based on pathological and genetic findings, we established the same clonal origin of both tumors. Currently, the diagnosis of an intraluminal CRC metastasis relies on histologic and immunohistochemistry findings. We suggest that genetic studies at the individual cell level by FISH techniques may be useful in order to differentiate synchronous from intraluminal metastasis.

Gouverneur' syndrome in a young Hispanic patient: A case report of a rare presentation of a rectal adenocarcinoma tumor

This is an unusual case report of 32-year-old Hispanic male who presented with an early-onset advanced stage colorectal cancer with an enterovesical fistula. A 32-year-old man presented to our institution referring suprapubic pain, urinary frequency, dysuria and tenesmus for several weeks suggesting Gouverneur’s syndrome. Patient had been treated with oral antibiotics for his recurrent urinary tract infections without resolution. Associated unintentional weight loss, decreased appetite and suprapubic pain raised concern for occult malignancy. Abdominopelvic computed tomography scan revealed a rectal mass with invasion to bladder. Colonoscopy biopsy confirmed diagnosis of moderately differentiated rectal adenocarcinoma. This report provides vital information about clinical presentations of enterovesical fistula in an imposed rectal adenocarcinoma in a young Hispanic adult with no previous family or medical history. A thorough clinical assessment must be taken to ensure accurate diagnosis and early detection of colorectal cancer in the young Hispanic population.

A rare case of rectal cancer with perianal metastasis: a case report

Background

Cancer metastasis from colon cancer to an anal fistula is very rare. We herein reported a rare case in which local excision was performed for metastatic anal fistula cancer originating from rectal cancer.

Case presentation

A 68-year-old man was referred to our institution with a diagnosis of rectal cancer. He had complained of anal fistula for 5 years. Based on a recent history of cerebral infarction, Hartmann’s operation was performed to treat the rectal cancer after the administration of preoperative chemotherapy for 3 months. However, 1 month after Hartmann’s operation, the anal fistula was found to have worsened. Pelvic magnetic resonance imaging (MRI) revealed tumor formation at the perianal lesion. Metastatic anal fistula cancer originating from the rectal cancer was diagnosed based on the examination of the biopsied tissue. We selected local excision because the anal tumor had not invaded the surrounding tissue. There has been no recurrence in the 31 months after the curative operation.

Conclusion

Metastatic cancer should be ruled out when treating left-sided colon cancer with anal fistula. Local excision is one possible treatment for metastatic anal fistula cancer.

Synchronous Sigmoid Colon Cancer Seeding a Fistula-in-Ano

A seeded fistula-in-ano from a synchronous sigmoid colon cancer is rare. The literature is still divided regarding the standard treatment, although an abdominoperineal resection is considered the best option when curative resection is possible. This case is distinct from previous reports, as the patient had known metastatic liver disease before surgery, and proceeded with a pan-proctocolectomy after neo-adjuvant chemotherapy. The patient died 20 months post-operatively of his metastatic liver disease, having been otherwise asymptomatic for eight months on continued chemotherapy, before commencing palliative treatment (completed five cycles). Given its rarity, a low suspicion to biopsy a fistula-in-ano is advocated, and the exclusion of malignancy should be considered prior to surgery.

Synchronous mucinous adenocarcinoma of the recto sigmoid revealed by and seeding an anal fistula. (A case report and review of the literature)

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The diagnosis of such conditions remains difficult when the colonic tumor is unknown and the chronic lesion of anal fistula seems to be a benign condition.

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The management of these cases remain controversial.

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The aim of this study highlights the importance of high suspicion with further investigation and the need of biopsy in all anal fistulas.

Introduction

There are few cases of synchronous rectal adenocarcinoma revealed by an anal fistula. The diagnosis of synchronous mucinous adenocarcinoma of the recto sigmoid and anal canal remains difficult. The chronic anal fistula can be mistaken as the common manifestation of a benign perianal abscess or fistula.

Case presentation

We present a rare case of a Greek Caucasian 79 year old male patient with anal fistula and a recurrent perianal abscess who subsequently was found to have developed synchronous rectosigmoid and perianal mucinous adenocarcinoma on biopsy. The histological exam revealed mucinous adenocarcinoma in two sites, representing two tumors, cells were immunopositive for cytokeratin 20 and negative in cytokeratin 7. The patient underwent “laparoscopic extralevator abdominoperineal excision ” with both lesions being resected. There is no recurrence after four years of follow up.

Conclusions

This case highlights the importance of high suspicion, further investigation and the need of biopsy in all anal fistulae.

Anal metastasis of rectal cancer-adenocarcinoma of squamous cells: a case report and literature review

Anal metastasis of colorectal cancer is very rare and is usually associated with a history of anal disease, including anal fistula, fissure, hemorrhoidectomy, and anastomotic injury. We report a case of rectal cancer with a synchronous anal metastasis consisting of adenocarcinoma of squamous cells without a history of anal disease. A 60-year-old woman had a chief complaint of melena. She had a 1.5-cm anal tumor on the perianal skin, and a Bollman type 2 rectal tumor on the Ra portion was found on colonoscopy. Biopsy of both tumors revealed a similar histology of well- to moderately differentiated adenocarcinoma. There was no sign of metastases in lymph nodes or other organs. For the purpose of diagnosis and treatment, transperineal local resection of the anal tumor was performed, and it was histologically identified as adenocarcinoma of squamous cells with no invasion to muscles, lymph ducts, or microvessels. The pathological margin was free. Then, to achieve radical cure, laparoscopic low anterior resection (LAR) with D3 lymphadenectomy was performed. The histological diagnosis of the anal tumor was adenocarcinoma of squamous cells without invasion to muscles, lymph ducts, or vessels. The surgical margin was completely free. Immunohistochemical analysis of both tumors revealed similar staining patterns, and the final diagnosis was rectal cancer with metastasis to the anal skin. The patient received no postoperative therapy, and no recurrences have been observed 12 months after surgery. We expect that our sphincter-preserving surgical strategy provided a good prognosis for the synchronous rectal cancer and anal metastasis. This is a rare report of a case with an anal metastasis of colorectal cancer on perianal squamous cells without a history of anal disease that was resected while preserving anal function.

Colorectal cancer implant in an external hemorrhoidal skin tag

External hemorrhoidal skin tags are generally benign. Colorectal cancer metastases to the squamous epithelium of perianal skin tags without other evidence of disseminated disease is a very rare finding. We present the case of a 61-year-old man with metastasis to an external hemorrhoidal skin tag from a midrectal primary adenocarcinoma. This case report highlights the importance of close examination of the anus during surgical planning for colorectal cancers. Abnormal findings of the perianal skin suggesting an implant or metastatic disease warrant biopsy, as distal spread and seeding can occur. In our patient, this finding appropriately changed surgical management.

A case of metastatic carcinoma of anal fistula caused by implantation from rectal cancer

This case involved an 80-year-old man who was seen for melena. Further testing revealed a tubular adenocarcinoma 50 mm in size in the rectum. In addition, an anal fistula was noted behind the anus along with induration. A biopsy of tissue from the external (secondary) opening of the fistula also revealed adenocarcinoma. Nodules suspected of being metastases were noted in both lung fields. The patient was diagnosed with rectal cancer, a cancer arising from an anal fistula, and a metastatic pulmonary tumor, and neoadjuvant chemotherapy was begun. A laparoscopic abdominoperineal resection was performed 34 days after 6 cycles of mFOLFOX-6 therapy. Based on pathology, the rectal cancer was diagnosed as moderately differentiated adenocarcinoma, and this adenocarcinoma had lymph node metastasis (yp T3N2aM1b). There was no communication between the rectal lesion and the anal fistula, and a moderately differentiated tubular adenocarcinoma resembling the rectal lesion was noted in the anal fistula. Immunohistochemical staining indicated that both the rectal lesion and anal fistula were cytokeratin 7 (CK7) (−) and cytokeratin 20 (CK20) (+), and the patient’s condition was diagnosed as implantation of rectal cancer in an anal fistula.

In instances where an anal fistula develops in colon cancer, cancer implantation in that fistula must also be taken into account, and further testing should be performed prior to surgery.

Endoscopic excision of synchronous large bowel polyps in the presence of colorectal carcinoma: is the fear of malignant cell implantation justified? A systematic review of the literature

AIM

A systematic review of the literature was performed to establish evidence to support the practice that in the presence of a colonoscopically diagnosed colorectal cancer immediate endoscopic excision of synchronous polyps should not be performed due to the risk of malignant cell implantation at the polypectomy site.

METHOD

A systematic literature search was performed using Medline, Embase and the Cochrane Central Register of Controlled Trials to identify studies comparing the rate of implantation of colorectal cancer cells in normal and damaged colonic mucosa and reports of colorectal cancer cells seeding into sites of damaged mucosa after polypectomy.

RESULTS

No randomized controlled trials were identified. Three studies involving mammalian models of colonic mucosal damage were included. Pooling relevant results revealed that out of 59 exposed mammals only one developed tumour cell implantation at a site of colonic mucosal damage. This equates to a mammalian in vivo experimental risk of malignant cell implantation of 1.6%.

CONCLUSION

The topic of colorectal cancer seeding following endoscopic procedures has received little attention. This review suggests that in the presence of a proximal colonic carcinoma there is a negligible risk of malignant implantation if a more distal polyp is endoscopically excised.