Mucinous adenocarcinoma on perianal fistula. A rising entity?

Chronic fistula in ano associated with adenocarcinoma: a case report with a review of the literature

The malignant transformation of chronic fistula in ano is rare, accounting for 3% to 11% of all anal canal malignancies. It results from long-standing inflammation and chronic irritation. No guidelines are available for the management of these cases. We herein present a case report of a 55-year-old man who presented with a history of constipation, perianal pain, and discharging fistula in ano of 4-year duration and underwent fistula surgery with recurrence. Biopsy of the fistulous tract revealed adenocarcinoma. He received neoadjuvant chemoradiotherapy, followed by abdominoperineal excision including excision of the fistulous tract. After 18 months of follow-up, he is free of recurrence. We present this case with a review of the literature, highlighting the management strategies.

Perianal Mucinous Adenocarcinoma: A Case of Recurrent Anal Fistula

An anal fistula is a fairly common clinical condition, with a very low incidence of malignant transformation. Mucinous adenocarcinoma is a subtype of adenocarcinoma, and its occurrence within perianal fistula tracts is quite rare. This case report describes a 54-year-old male patient with recurrent anal fistula, initially suspected of Crohn's disease (CD), and ultimately diagnosed with perianal mucinous adenocarcinoma. After our joint internal medicine, surgery, and imaging reassessment, the diagnosis was confirmed. Anal fistula is usually considered a benign lesion, but it may also be associated with other diseases. Due to overlapping symptoms of related diseases, the investigation of malignant lesions is often overlooked. This case report emphasizes the importance of timely referral and multidisciplinary management for disease diagnosis and early treatment.

Perianal Mucinous Adenocarcinoma Found Incidentally From Perianal Mass

Anal mucinous adenocarcinomas are very rare and usually arise from anal fistulas. We report a case of a 73-year-old man with a past medical history of hypertension admitted to our facility for evaluation of bleeding from a large, tender, left gluteal perianal mass. The patient reported the mass had been growing for over six years. On examination, an ulcerated, fungating large exophytic lesion was found extending from the anal verge laterally engulfing the left gluteus. The patient was anemic with low hemoglobin and hematocrit, as well as an elevated carcinoembryonic antigen level. A colonoscopy was performed during which an internal opening of a left-sided anal fistula was identified. The mass was biopsied and returned positive for a mucinous adenocarcinoma. Staging imaging including a computed tomography scan of the chest abdomen and pelvis did not show any metastatic disease. A magnetic resonance image of the pelvis revealed a locally invasive, heterogeneous tumor extending from the perianal soft tissue to the posterior wall of the anal canal and lower rectum. The patient was discussed at the interdisciplinary tumor board and completed five weeks of concurrent chemotherapy and radiation with 5-fluorouracil and a total of 28 fractions of radiation. He then underwent abdominoperineal resection with a vertical rectus abdominis myocutaneous flap. The patient was placed in the surgical intensive care unit and subsequently discharged in stable condition on postoperative day 14. This case highlights the presentation, diagnosis, and management of anal mucinous adenocarcinoma.

Adjuvant chemoradiotherapy does not improve outcomes in patients with fistula-associated anal adenocarcinoma undergoing abdominoperineal resection

OBJECTIVE

Abdominoperineal resection (APR) is currently established as a standard treatment regimen for fistula-associated anal adenocarcinoma (FAAA), however, the efficacy of chemoradiotherapy (CRT) remains unclear. The aim of this study is to evaluate the role of CRT in patients with FAAA treated with APR through single-center experience and literature review.

METHODS

A retrospective review was performed on patients with FAAA consecutive treated in our institution from 2005 to 2022. In addition, a systematic literature search was performed using PubMed and MEDLINE. All patients with FAAA who received APR in our institution and reported in the literature were included and divided into three categories for statistical analysis: APR alone (APR group), neoadjuvant therapy combined APR (CRT+APR group), and APR combined postoperative therapy (APR+CRT group).

RESULTS

Fifteen patients with FAAA were identified from our retrospective charts review. At a median follow-up time of 18 months, the recurrence-free survival rate was 53.3% and the survival rate was 73.3%. Eight patients underwent APR and 6 received postoperative chemotherapy. Among them, one died, one developed recurrence and the remaining six patients were alive with disease free. We found 37 publications describing 62 patients with FAAA treated with APR. Clinical data from these articles were analyzed together with the 8 cases in our institution. The overall survival rates were 94.1%, 70.8%, and 38.5% at 1-, 3-, 5-years respectively. Combining (neo)adjuvant therapy did not appear to improve outcomes in FAAA treated with APR (CRT+APR vs. APR, p=0.977; APR+CRT vs. APR, p=0.351). Lymph node involvement was shown to be significantly associated with poor outcomes by multivariate analysis (p=0.020).

CONCLUSIONS

For patients with FAAA without lymph node involvement, APR is adequate to control disease and the addition of CRT does not appear to prolong survival.

Mucinous adenocarcinoma in perianal fistula in Crohn's disease: Case report and literature review

Introduction and importance

Crohn's disease (CD) is a chronic bowel disease that, due to exacerbated inflammation, can lead to complications such as the development of perianal fistulas. The development of mucinous adenocarcinoma in perianal fistulas in patients with CD is rare and, consequently, few reports exist in the literature.

Case presentation

We report the case of a 71-year-old man diagnosed 22 years ago with CD with perineal involvement, who came with complaints of intense perianal pain, a gluteal mass, and local bleeding. Tomography of his abdomen showed an expansive, heterogeneous, and solid perianal mass on the right, with interspersed necrotic/liquefied areas and possible mucinous content. The patient was referred to the surgery department for an incisional biopsy, which confirmed mucinous adenocarcinoma. The patient underwent extra levator abdominoperineal rectal resection (APR) with partial prostatectomy.

Clinical discussion

Perineal mucinous adenocarcinoma arising in a fistula associated with CD is very rare. Since the symptoms overlap, early diagnosis of malignancy is difficult. Histological analysis is the gold standard for its diagnosis. Surgical resection through APR is well-established and, despite being a complex procedure with potential complications, tends to have good results. However, the locoregional and inguinal lymph node involvement was related to a worse progression in this case.

Conclusion

The diagnostic hypothesis of mucinous adenocarcinoma should be suspected in CD patients who present long-term perineal involvement with fistulas. Biopsies and imaging exams should be performed to aid the diagnosis of the condition and thus contribute to the surgical plan.

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Mucinous adenocarcinoma in perianal fistulas from CD patients is extremely rare.

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Magnetic resonance imaging findings help in Mucinous adenocarcinoma diagnosis.

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Locoregional and inguinal lymph node involvement is related to a worse progression.

Perianal Inflammation or Something More?

Perianal fistulae are commonly complicated by abscesses and ramifications, which have well-recognized imaging morphology. Less commonly, atypical findings of solid enhancing mass-like lesions with no fluid component are associated with chronic and recurrent fistulae, the etiology of which includes inflammatory masses as well as locally aggressive malignancy. The latter predicts poorer prognosis and warrants extensive surgical resection. The reading radiologist must identify the unusual appearance, be aware of the possible etiologies, and if appropriate recommend prompt tissue sampling to exclude malignancy. This is pertinent as it determines surgical management, which is crucial in achieving a potential curative outcome.

Perianal mucinous adenocarcinoma with dysplastic polyps of the colon: A case report

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Mucinous adenocarcinoma of the perianal region is extremely rare (6.9% of anal neoplasms and 2–3% of all gastrointestinal malignancies).

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Given the low incidence of this tumor, it is often missed at initial evaluation.

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Association with chronic perianal fistula are common and inflammatory symptoms can be misleading with delay in diagnosis.

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The paucity of publications leads to a lack of consensus on both diagnostic and therapeutic approaches.

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The understanding of the etiopathogenic mechanisms may lead to the development of novel diagnostic and therapeutic protocols.

Introduction

Perianal mucinous adenocarcinoma is rarely encountered in the setting of anal neoplasms. The rarity of the disease and the paucity of publications on this topic are responsible for a lack of diagnostic and therapeutic guidelines.

Presentation of case

An 80-year-old man with mucinous adenocarcinoma of the anal canal associated with dysplastic polyps of the colon was treated by multiple endoscopic polypectomies and abdomino-perineal resection of the rectum. We discuss the management of this rare case from the diagnosis up to one-year follow-up.

Discussion

Perianal mucinous adenocarcinoma is a very rare entity frequently combined with chronic fistulas. Inflammatory symptoms may mislead its diagnosis, which is often delayed. The unique association between perianal mucinous adenocarcinoma and dysplastic polyps of the colon, that we have reported, may suggest a secondary etiology. High clinical suspicion is important for early and correct diagnosis, which should be based on endoanal ultrasound and/or magnetic resonance imaging followed by deep tissue biopsies.

Conclusion

We stress the importance of accumulating such cases in the literature. The understanding of the etiopathogenic mechanisms may lead to the development of novel diagnostic and therapeutic protocols.

Magnetic resonance imaging findings of carcinoma arising from anal fistula: A retrospective study in a single institution

BACKGROUND

Magnetic resonance imaging (MRI) is currently the standard investigation for suspected perianal diseases. Carcinoma arising from anal fistula is very rare, and early diagnosis is often difficult.

AIM

To describe and summarize the MRI findings of carcinoma arising from anal fistula.

METHODS

In this retrospective study, records of ten patients diagnosed with carcinoma arising from anal fistula and confirmed by surgery (n = 7) or biopsy (n = 3) between June 2006 and August 2018 were analyzed. All patients underwent preoperative pelvic MRI. Morphologic features, signal characteristics, fistula between the mass and the anus, contrast enhancement of mass, signal and enhancement of peritumoral areas, and regional lymphadenopathy were assessed.

RESULTS

All ten tumors were solitary (8 mucinous adenocarcinomas and 2 adenocarcinomas). The maximum diameter of the tumors ranged from 3.4 cm to 12.4 cm (median: 4.15 cm; mean: 5.68 cm). Eight patients had a fistula between the mass and the anus. Contrast enhancement of the peritumoral areas was noted in three (3/5) patients. Perirectal or inguinal lymphadenopathy was noted in seven patients. Most lesions of mucinous adenocarcinoma were multiloculated and cauliflower-like, with a thin capsule and focally unclear boundary. They were markedly hyperintense on fat-suppressed T2WI, slightly hyperintense with focal hyperintensity on diffusion-weighted imaging (DWI), and hyperintense with focal hypointensity on apparent diffusion coefficient (ADC) map, with progressive mesh-like contrast enhancement. Adenocarcinomas had an infiltrative margin without a capsule and appeared heterogeneously hyperintense or slightly hyperintense on fat-suppressed T2WI, hyperintense on DWI, and hypointense on ADC map, with persistent heterogeneous enhancement.

CONCLUSION

Our study highlighted several characteristic and potentially helpful MRI findings to diagnose carcinomas arising from anal fistula.

Mucinous adenocarcinoma of the buttock associated with hidradenitis: A case report

BACKGROUND

Mucinous adenocarcinomas of the buttock are rare and have an uncertain etiology and natural course. They are usually related to chronic anal fistulas, hidradenitis suppurativa, or Crohn's disease. Here, we report a case of mucinous adenocarcinoma associated with hidradenitis and contradictory immunochemistry results.

CASE SUMMARY

A 62-year-old man complained of recurrent abscesses of the buttock for 3 years. He had several scars and nodules in bilateral buttocks, with purulent discharge. The skin lesions did not appear to originate from the anus. The patient was diagnosed with recurrent abscesses due to hidradenitis suppurativa at the first visit. He showed purulent and subsequent mucin discharge in the first operation and was diagnosed with mucinous adenocarcinoma. Several examinations were performed to determine disease origin and staging. There were no significant findings or evidence of anal fistulas. Hence, he underwent wide local excision and V-Y advancement flap in the second operation. The final diagnosis was mucinous adenocarcinoma without any evidence of anal fistulas. Additional immunochemistry test results were negative for cytokeratin (CK) 7 and positive for CK20 and CDX2, with a colorectal origin. A pathologist suggested that the disease originated from a chronic anal fistula. The patient has remained free of recurrence for 24 mo.

CONCLUSION

Although the patient with mucinous adenocarcinoma showed an atypical course, immunochemistry helped detect the disease origin.

Extensive Resection for Treatment of Locally Advanced Primary Mucinous Adenocarcinoma Arising From Fistula-in-Ano

We report a case of a 66-year-old male who presented with a locally advanced primary mucinous adenocarcinoma arising from a fistula-in-ano. The presentation was typical for perianal sepsis and fistula-in-ano with anal pain and chronic discharge. Initial treatments with fistula debridement and seton were performed. Subsequent review of histology revealed underlying adenocarcinoma, while magnetic resonance imaging (MRI) showed local invasion into the prostate. The patient received neoadjuvant chemoradiotherapy followed by pelvic exenteration to maximize the chance of achieving cure. Features of this case are discussed together with its implications, including treatment guidelines and typical MRI findings.

Incidental discovery of mucinous adenocarcinoma from a suspected inflammatory perianal mass

Mucinous adenocarcinoma is a rare tumor that may be associated with longstanding perianal fistulas. It represents 6.9% of all anal cancers. The diagnosis of this malignancy can be delayed because the symptoms experienced by people with the disease are usually attributed to the fistula and not to malignant transformation. As a result, the diagnosis of perianal mucinous adenocarcinoma in the setting of chronic perianal fistulas requires a high index of clinical suspicion and specific histological features.