A Case of Large Perianal Mucinous Adenocarcinoma Arising from Recurrent Abscess and Complex Fistulae

Mucinous adenocarcinoma arising from a complex perianal fistula: a diagnostic and therapeutic challenge

We present a case of a 64-year-old male with a history of perianal abscesses that have been surgically treated on 10 occasions. Eight months after the last drainage procedure, he presented with a new abscess. Drainage was performed, revealing a cavity with smooth walls, a chronic appearance, filled with mucoid material. An internal fistulous opening was identified at the 6 o'clock position above the anorectal line, which communicated with the described cavity, forming a trans-sphincteric fistula to the mid-anal canal. Biopsy with pathological anatomy showed a mucinous adenocarcinoma with possible intestinal origin (CK20+, CDX2+, TTF1-, CK7+). After completing the evaluation, he was diagnosed with T4N1M0 rectal neoplasia. A diverting colostomy was performed, followed by neoadjuvant therapy, and subsequently, a laparoscopic abdominoperineal amputation. Pathological anatomy revealed residual adenocarcinoma ypT2N0 N0V0L0, R0. This case is notable for both the rarity of a mucinous adenocarcinoma originating in a perianal fistula and the nonspecific clinical presentation of such tumors. Clinical suspicion is crucial, especially in cases of recurrent abscesses with the discharge of mucoid material through fistulous openings, prompting the need for biopsies to ensure proper diagnosis and subsequent optimal 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.

Risk of Anorectal Cancer Associated with Benign Anal Inflammatory Diseases: A Retrospective Matched Cohort Study

Purpose: The purpose of our study was to evaluate the relationship between benign anal inflammatory diseases and anorectal cancer and assess its risk factors. Methods: A retrospective matched cohort study was conducted that included data from 2002 to 2013. The National Health Insurance Service National Sample Cohort data from 2002 to 2013 was used for the study. Of a total study population of 143,884 individuals, 28,110 individuals with anal fissures were assigned to the case group, while 115,774 individuals without anal fissures were assigned to the control group based on the 1:4 propensity score matching age, sex, and year (case: diagnosed year, control: health service received year). Results: The risk of anorectal cancer was higher in the case group (hazard ratio [HR]: 1.95, 95% confidence interval [CI]: 1.51–2.53) compared to the control group. After grouping anorectal cancers into anal cancer and rectal cancer, the risk remained higher in the case group (anal cancer HR: 2.79, 95% CI: 1.48–5.27; rectal cancer HR: 1.82, 95% CI; 1.37–2.42). The case group was further categorized into patients with fissures and patients with fistulas; patients with fissures showed a higher risk of developing anorectal cancer than patients with fistulas (HR: 2.05, 95% CI: 1.53–2.73 vs. HR: 1.73, 95% CI: 1.13–2.66). Study participants in their 30s and 40s had a 4.19- and 7.39-times higher risk of anorectal cancer compared to those in the higher age groups (0.64–1.84), while patients who did not have inflammatory bowel disease (IBD) had a higher risk of developing anorectal cancer (HR: 2.09, 95% CI: 1.56–2.80). Conclusions and Relevance: Patients with anal fistulas or fissures have an increased risk of being diagnosed with anorectal cancer, especially at a young age and even without IBD.

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.

Deep Learning-Based Magnetic Resonance Imaging Features in Diagnosis of Perianal Abscess and Fistula Formation

There was an investigation of the diagnostic and prognostic effect of magnetic resonance imaging (MRI) based on multimodal feature fusion algorithm for impotence of perianal abscess. In this study, the second to fifth convolution blocks of the visual geometric group network were applied to extract the depth features in the way of transfer learning, and a multimode feature fusion algorithm was constructed. The whole network was trained by maximizing the energy proportion of the feature layers, which was compared with the fully convolutional neural network (FCN) algorithm. Then, this algorithm was adopted to the imaging diagnosis of 50 patients with anorectal diseases admitted to our hospital, and it was found that the similarity coefficient (85.37%), accuracy (80.02%), and recall rate (79.38%) of the improved deep learning algorithm were higher markedly than those of the FCN algorithm (70.18%, 67.82%, and 66.92%) (P < 0.05). As the number of convolutional layers increased, the segmentation accuracy of the convolutional neural network (CNN) algorithm was also improved. The detection rate of the observation group (84%) rose hugely compared with the control group (64%), and the difference was statistically obvious (P < 0.05). Besides, the detection accuracy of abscess location (84%), impotent tract location (80%), and internal orifice location (92%) in patients from the observation group was higher substantially than the accuracy of abscess location (60%), impotent tract location (68%), and internal orifice location (72%) from the control group (P < 0.05). In conclusion, the performance of the multimodal feature fusion algorithm was better, and the MRI image feature analysis based on this algorithm had a higher diagnostic accuracy, which had a positive effect on improving the detection rate, detection accuracy, and disease classification.

CT and MRI Evaluations in Crohn's Complications: A Guide for the Radiologist

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory intestinal conditions with unknown etiology. Crohn's disease (CD) and ulcerative colitis (UC) are the two main types of IBD and they have some interchangeable and some different clinical and pathological characteristics. When diagnosis is performed for the first time, the majority of CD patients have a predominant inflammatory condition. As the disease progresses most patients experience the development of complications, such as abscesses, fistulas, perforation, strictures, and others. Both computed tomography (CT) and Magnetic Resonance Imaging (MRI) allow great view of the whole length of the intestinal tract together with the eventual extra-and intra-intestinal complications. MR enterography (MRE) and CT enterography (CTE), performed after oral administrations of contrast medium, have similar diagnostic accuracy for the diagnosis of CD and its complications. Even though CT is still the most familiar diagnostic technique used for studying CD worldwide, MRE have several important benefits that are leading to rapid increase in its employment in the last years. In particular, MRE allows a superior soft tissue contrast resolution compared to CT, offering a better visualization of bowel wall and its inflammatory and fibrotic characteristics. Moreover, Pelvic Magnetic Resonance is the principal technique in patients with perianal disease due to its ability of providing precise and fine detail images of the sphincter complex, which are crucial for evaluating pelvic disease. In this paper we describe common and uncommon complications in patients with CD, and explain how to identify their findings in CT and MR exams.

Deep Learning-Based Computed Tomography Image Features in the Detection and Diagnosis of Perianal Abscess Tissue

The performance characteristics of deep learning fully convolutional neural network (DLFCNN) algorithm-based computed tomography (CT) images were investigated in the detection and diagnosis of perianal abscess tissue. 60 patients who were medically diagnosed as perianal abscesses in the hospital were selected as the experimental group, and 60 healthy volunteers were selected as the control group. In this study, the DLFCNN algorithm based on deep learning was compared with the CNN algorithm and applied to the segmentation training of CT images of patients with perianal abscesses. Then, the segmentation metrics Jaccard, Dice coefficient, precision rate, and recall rate were compared by extracting the region of interest. The results showed that Jaccard (0.7326) calculated by the CNN algorithm was sharply lower than that of the DLFCNN algorithm (0.8525), and the Dice coefficient (0.7264) was also steeply lower than that of the DLFCNN algorithm (0.8434) (P < 0.05). The thickness range of the epidermis and dermis in patients from the experimental group was 4.1–4.9 mm, which was markedly greater than the range of the control group (1.8–3.6 mm) (P < 0.05). Besides, the CT value of the subcutaneous fascia in the experimental group (−95.45 ± 8.26) hugely reduced compared with the control group (−76.34 ± 7.69) (P < 0.05). The accuracy rate of the patients with perianal abscesses was 96.67% by multislice spiral CT (MSCT). Therefore, the DLFCNN algorithm in this study had good stability and good segmentation effect. The skin at the focal site of anal abscess was obviously thickened, and it was simple and accurate to use CT images in the diagnosis of patients with perianal abscesses, which could effectively locate the lesion and clarify the relationship between the lesion and the surrounding structure.