Squamous cell carcinoma arising from recurrent anal fistula

Squamous cell carcinoma arising from anal fistula in an HIV-positive individual: a case report

Chronic anal fistula represents a prevalent form of perianal disease that frequently originates from perianal infection. Specifically, perianal abscesses that are inadequately or improperly treated are susceptible to the development of chronic anal fistulas. In HIV-infected individuals, an impaired immune system significantly diminishes the body's capacity to combat infections and inflammation, thereby complicating the healing process of anal fistulas. Moreover, the impact of HIV on tissue repair results in a markedly prolonged healing process for wounds and tissue damage in these patients, exacerbating the difficulty in anal fistula resolution. Chronic anal fistulas that remain untreated for extended periods not only severely impair the patient's quality of life but also pose an increased risk of malignant transformation.

Radiation Therapy and Malignant Fistulae of Anorectal Cancers

PURPOSE

Though fistulization is a well-studied late toxicity of radiation therapy (RT), anorectal cancers (ARC) can present with malignant fistulae (MF) and negatively impact quality of life. The effect of RT, often combined with concurrent chemotherapy (CHT), on MF, needs systematic analysis, as practitioners are concerned that RT may exacerbate MF. We reviewed our institutional series evaluating the hypothesis that RT worsens MF.

METHODS AND MATERIALS

A single-institutional retrospective analysis of ARC patients receiving RT from 2006-2019 was performed. These patients were screened for MF. MF resected prior to RT and RT not directed at the site of MF were excluded. Effect was assessed by review of available follow-up documentation and imaging.

RESULTS

Six-hundred-and-thirty-nine patients with ARC were reviewed, and 47 had MF (7.4%). With a median follow-up of 22 months (range 2-133 months), RT improved MF in 17/29 (59%) of evaluable patients, with 9/29 (31.0%) having resolution. Median time to improvement was 50 days (range 25-117 days); median duration of improvement was 161 days (range 0-1,941 days). MF persisted in 12/29 (41%), with persistent local disease in all cases; in two cases, MF worsened concomitant with local progression.

CONCLUSIONS

Seven-point-four percent of ARC patients presented with MF. RT led to improvement or resolution in more than half of evaluable patients. Persistence or worsening of MF was only observed in patients with refractory or progressive local disease. Based on our findings, MF is not a contraindication to RT, and may be considered as an independent indication for palliative RT.

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.

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.

A mismatch repair-deficient and HPV-negative anorectal squamous cell carcinoma

Invasive primary squamous cell carcinomas involving the anorectal region are challenging to manage. Microsatellite instability has been shown to impact clinical courses and outcomes of patients affected by many types of carcinomas. To the best of our knowledge, there are no reports on microsatellite instability in anorectal squamous cell carcinomas. Here, we report a HPV-negative anorectal squamous cell carcinoma which, despite cisplatin-based chemoradiation therapy, showed progression. Interestingly, after identification of its mismatch repair-deficiency (MLH1/PMS2-absent, MSH2/MSH6-intact), pembrolizumab-based immunotherapy was initiated, leading to a marked clinical response. This unique case illustrates that microsatellite instability testing and immunotherapy targeting immune checkpoint blockade should be considered for managing anorectal squamous cell carcinomas that fail conventional chemoradiation therapies or when patients are non-surgical candidates. This report provides the first evidence of microsatellite instability in anorectal squamous cell carcinomas and supports the role for microsatellite instability testing in this cancer type to optimize patient management.

Adenocarcinoma within anorectal fistulae: different clinicopathological characteristics between Crohn's disease-associated type and the usual type

Adenocarcinoma within anorectal fistulae is rare and is sometimes associated with Crohn's disease. Crohn's disease-associated adenocarcinoma within anorectal fistulae has a poor prognosis; however, little is known about the clinicopathological differences between Crohn's disease-associated adenocarcinoma within anorectal fistulae and usual adenocarcinoma within anorectal fistulae. We retrospectively searched patients' charts and pathology archives at Tokyo Yamate Medical Center and Tokyo Medical and Dental University Hospital for adenocarcinoma within anorectal fistulae. Clinical and pathological data were collected and immunohistochemical examinations were conducted. Overall survival rate was estimated using the Kaplan-Meier method. Prognostic factors of overall survival were assessed using univariate and multivariate Cox regression analyses. We examined 82 cases of adenocarcinoma within anorectal fistulae. Fifty-nine of 82 cases (72%) had usual adenocarcinoma within anorectal fistulae, while the remaining 23 cases (28%) had Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae were diagnosed at a younger age and at a more advanced stage than those with usual adenocarcinoma within anorectal fistulae. Macroscopic and histological types were also different between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Crohn's disease-associated adenocarcinoma within anorectal fistulae included more ulcerative types and high-grade adenocarcinomas. The rate of lymphovascular invasion was higher in Crohn's disease-associated adenocarcinoma within anorectal fistulae. Immunohistochemically, the expression of E-cadherin, p53, and MUC5AC differed between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae exhibited worse overall survival than those with usual adenocarcinoma within anorectal fistulae, and vascular invasion was the strongest significant independent predictor of overall survival in patients with adenocarcinoma within anorectal fistulae. In conclusion, usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae have different clinicopathological characteristics and should be considered separate clinical entities.

Two Cases of Verrucous Carcinoma: Revisiting the Definition

Verrucous carcinoma (VC) is an uncommon, distinct type of well-differentiated squamous cell carcinoma. Here we present two cases of VC, one arising from the lower leg and the other from genital skin. Case 1, a female patient, aged 95 years, had a brownish verrucous plaque on her right lower leg. Histopathologically, epithelial tumor cells grew pushing the stroma, while the basement membrane was intact. No prominent cellular atypia or hyperchromatin was found. Case 2, a male patient, aged 53 years, had a verrucous plaque at the border between his scrotum and inner aspect of his thigh. A pathological diagnosis of VC was made using an excisional specimen. Making a definitive diagnosis of VC is challenging but crucial. Pathological diagnosis using a small specimen might cause underdiagnosis or overdiagnosis. To avoid this, pertinent pathological diagnosis using an ample specimen is required. We also revisited the definition of VC to precisely understand its nature.

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.

Squamous cell carcinoma arising from chronic sacrococcygeal pilonidal disease: a case report

Background

Sacrococcygeal pilonidal disease is a chronic, well-recognized entity, characterized by the recurrent formation of an abscess or draining sinus over the sacrococcygeal area. It is one of the most common surgical problems. Rarely, chronic inflammation and recurrent disease leads to malignant transformation, most commonly to squamous cell carcinoma (SCC).

Case presentation

We describe an extremely unusual case of SCC developing in a 60-year-old patient with a chronic pilonidal sinus complicated by an anal fistula. After wide surgical excision of the pilonidal sinus and fistulas and because of the poor healing process 6 months later, colonoscopy and a percutaneous fistulography were performed, revealing an anal canal-pilonidal fistula. Patient was treated with a more radical surgical resection with a prophylactic loop colostomy, but healing was not accelerated. Multiple biopsies were then taken from the surgical site at the time, which revealed the development of SCC. CT and MRI imaging techniques revealed SCC partial invasion of the coccyx and sacrum. As a result, aggressive surgical approach was decided. Histological examination revealed moderately to poorly differentiated SCC, and the patient was treated with adjuvant radiation therapy postoperatively. Nine months later, recurrence was found in the sacrum and para-aorta lymph nodes and the patient died shortly after. We discuss the clinical features, pathogenesis, treatment options, and prognosis of this rare malignant transformation.

Conclusions

The development of SCC in chronic pilonidal disease is a rare but serious complication. Symptoms are usually attributed to the sacrococcygeal pilonidal disease (SPD), and diagnosis is often made late by histological examination of biopsies. Malignant transformation should be suspected in chronic SPD with recurrent episodes of inflammation, repeated purulent discharge, poor healing, and chronic complex fistulas.

Cutaneous squamous cell carcinoma presenting as a wound with discharging sinus tracts in a wild African lion (Panthera leo)

A female wild African lion (Panthera leo) was presented with an 8-month history of a wound with multiple discharging sinus tracts on the left paw. Microscopical examination revealed squamous cell carcinoma (SCC). To the best of our knowledge, this is the first report of cutaneous SCC in an African lion. Cutaneous SCC presenting as discharging sinus tracts lined by neoplastic squamous cells has not been reported previously in animals.

Malignant melanoma arising from a perianal fistula and harbouring a BRAF gene mutation: a case report

Background

Melanoma of the anal region is a very uncommon disease, accounting for only 0.2-0.3% of all melanoma cases. Mutations of the BRAF gene are usually absent in melanomas occurring in this region as well as in other sun-protected regions. The development of a tumour in a longstanding perianal fistula is also extremely rare. More frequent is the case of a tumour presenting as a fistula, that is, the fistula being a consequence of the cancerous process, although we have found only two cases of fistula-generating melanomas reported in the literature.

Case Presentation

Here we report the case of a 38-year-old male who presented with a perianal fistula of four years of evolution. Histopathological examination of the fistulous tract confirmed the presence of malignant melanoma. Due to the small size and the central location of the melanoma inside the fistulous tract, we believe the melanoma reported here developed in the epithelium of the fistula once the latter was already formed. Resected sentinel lymph nodes were negative and the patient, after going through a wide local excision, remains disease-free nine years after diagnosis. DNA obtained from melanoma tissue was analysed by automated direct sequencing and the V600E (T1799A) mutation was detected in exon 15 of the BRAF gene.

Conclusion

Since fistulae experience persistent inflammation, the fact that this melanoma harbours a BRAF mutation strengthens the view that oxidative stress caused by inflammatory processes plays an important role in the genesis of BRAF gene mutations.

Squamous cell carcinoma arising from long-standing perianal fistula

Perianal fistula is a very common problem in general population. Ninety percent of perianal fistulae arise from infected anal glands, and they often give rise to perianal abscesses. Very rarely perianal fistulae and abscesses undergo malignant transformation and give rise to carcinomas, mainly adenocarcinomas. We are reporting a case of squamous cell carcinoma arising from long-standing perianal fistula and how we managed it surgically.