Angioleiomyomas are rare benign tumors, which take origin from smooth muscle fibers of the tunica media of veins. Even though angioleiomyomas can appear anywhere in the body, these masses are rarely occurred in the gastrointestinal system. This is the first reported case of perianal angioleiomyomas, where the tumor in close relation with the anal canal was investigated with endoanal ultrasonography. Local excision of such lesion is generally curative.

UNASSIGNED: Gastrointestinal stromal tumor (GIST) is rare because of its variable clinical incidence reported (from 0.4 to 2/100,000 per year) in the literature, mainly occurs primarily in the stomach and small intestine. GISTs in the perianal and perineal regions have been reported in a few pieces of literature. GIST located in the perianal and perineal regions may be misdiagnosed and missed due to atypical symptoms. We report two cases of GIST in rare sites and hope to reduce the occurrence of such events through a review of the relevant literature.
METHODS: We reported two cases of GIST located in the perianal and perineal regions with different symptoms. One case underwent an emergency procedure to stop bleeding and resect the mass, and the other case was discovered during the physical examination and slowly grew in the follow-up. Following the completion of the relevant examination, the patient underwent surgical resection. Both cases were finally diagnosed as GIST by immunohistochemistry.
UNASSIGNED: Due to atypical clinical symptoms of perianal and perineal GIST, definitive diagnosis depends on pathology and immunohistochemistry, which can lead to misdiagnosis and missed diagnosis. Surgical resection is the preferred option for localized masses. Surgical resection of GIST located in the perianal and perineal regions requires an appropriate surgical approach based on the patients\' actual condition, taking into account the protection of anal function and complete resection of the mass. Masses located in perianal and perineal region should be taken seriously by clinicians.

BACKGROUND: Perianal tuberculosis is extremely rare without previous or active pulmonary infection. Ulcerative skin lesion is a rare presentation of extrapulmonary tuberculosis in the oral, perianal, or genital mucosa and the adjacent skin.
METHODS: A 71-year-old woman complained of pain during evacuation and fecal incontinence for two years. There was an ulcerated lesion in the perianal and intergluteal region and perianal fistulous tracts. A polymerase chain reaction test on blood and biopsies of perianal ulcers, perianal fistula, and the intergluteal area was positive for Mycobacterium tuberculosis. The pathological examination revealed a chronic epithelioid granulomatous inflammatory process with the presence of multinucleated giant cells. After the end of the tuberculosis drug regimen, there was marked improvement in the patient\'s clinical condition.
CONCLUSIONS: Even in the absence of an identifiable primary focus, tuberculosis should be considered in the differential diagnosis of ulcerative and fistulous lesions of the perianal area.

The granular cell tumor or Abrikossoff\'s tumor is a rare tumor, most often benign in evolution. Malignant forms are exceptional. We report, here, a very rare case of granular cell tumor, localized in the perianal region, in a 54-year-old woman with lung metastases. CT and MRI with contrast showed a locally advanced tumor process in the right para-anal region associated with multiple \"balloon release\" lung lesions. The diagnosis was confirmed by immunostaining after surgical biopsy. Very few cases of malignant granular cell tumors with lung metastasis have been reported in the literature.

BACKGROUND: The surgical strategy for congenital perineal lipoma varies depending on the size, location, and accompanying congenital anomalies, with the optimum approach remaining to be determined. We herein report a case of congenital perianal lipoma that was first detected by prenatal ultrasound and review the literature.
METHODS: A female neonate was referred to us for the evaluation of a perianal mass. She had been considered to be male prenatally because fetal ultrasound showed a perineal mass similar to a scrotum and penis. A postnatal examination revealed an appropriate-for-age neonate with a soft round mass 1.5 cm in diameter just to the left of the anal verge. She passed urine and stool smoothly, and contrast enema confirmed no anorectal malformation. Magnetic resonance imaging showed that the lesion had a signal intensity consistent with fat located close to the anal sphincter, and no spinal anomaly (e.g., spina bifida) was identified. We excised the lesion (pathologically confirmed to be lipoma) simply at 2 months old, taking care to avoid damaging the anal sphincter by using a muscle stimulator. She has been doing well with good bowel movement and satisfactory cosmetic results for a follow-up period of one and a half years. Our literature search revealed 49 cases of perineal lipoma reported in English in the last 25 years, and 74% of them-including ours-had other congenital anomalies, the breakdown of which was anorectal malformation in 40% of cases, labioscrotal fold or accessory scrotum in 28%, and urogenital malformation, congenital pulmonary airway malformation, and disorder of sex differentiation. The prenatal detection of the lesion, as in our case, was quite rare.
CONCLUSIONS: A thorough physical examination after birth, magnetic resonance imaging and contrast enema to identify the nature of the perineal lipoma and accompanying anomalies are crucial for planning the surgical strategy. The lesion may be deeply interspersed between the sphincter muscle, especially when it accompanies anorectal anomaly. A muscle stimulator is useful for preserving and repairing the sphincter muscles during resection in order to ensure satisfactory bowel movement.

BACKGROUND: The timely management of pediatric Crohn\'s disease (CD), and specifically perianal CD, is important owing to the possible adverse effects on growth, development, and quality of life. Perianal involvement is increasingly common, with up to 62% of pediatric CD patients affected. Presently, literature addressing the management of perianal CD has focused primarily on adults, with findings that cannot always be extrapolated to the pediatric population. We aimed to review the rates of healing, recurrence, and need for surgical intervention in perianal CD to provide evidence-based recommendations for the ideal management in children.
METHODS: We conducted a systematic review of CENTRAL, PubMed, Medline, and EMBASE databases (January 1997-December 2017) in accordance with PRISMA. Two independent reviewers performed data extraction.
RESULTS: Ten studies met the inclusion criteria with a combined total of 538 patients. Median study population size was 17 (range 7-276), with a median age at intervention of 13.9 years (range 1-18). Seton placement allowed complete healing in 28.6% of children. Similar results (28.5%) were seen in children undergoing fecal diversion. One study demonstrated complete resolution of fistulizing disease in 70% of children treated with infliximab (IFX). One quarter of patients treated with IFX required further surgical intervention for disease control. Recurrence occurred most frequently in children undergoing Seton placement alone (5/14, 35.7%), compared with IFX (46/197, 23.4%) and combination therapy (12/276, 4.3%).
CONCLUSIONS: In the pediatric population, a combination of medical and surgical treatment is required to control perianal CD, with fewer side effects.
METHODS: Level II.

Granular cell tumor (GCT) is a rare soft tissue neoplasm. At present, there is limited information available on the incidence, diagnosis, and treatment of GCTs. Therefore, we perform magnetic resonance imaging (MRI) of a perianal GCT case and review the literature of other reported cases to obtain a more comprehensive understanding of the disease. Here, we describe a rare case of perianal GCT in a 53-year-old female who presented with recurrent abdominal pain. Contrast-enhanced MRI demonstrated a well-defined perianal GCT mass, and the diagnosis was confirmed by immunostaining after mass excision. During a 10-month follow-up, there had been no evidence of recurrence. In addition, we discussed the findings of other perianal GCT cases, with regard to their age, gender, MRI analysis results, pathologic features, and treatment outcomes.

Tumor necrosis factor (TNF) antagonists are considered the cornerstone therapy for fistulizing perianal Crohn\'s disease (PCD), yet a substantial proportion of patients fail to achieve healing. Therefore, we reviewed the evidence for strategies to enhance the efficacy of TNF antagonists for PCD. A systematic search of electronic databases through July 2018 was performed to identify studies that assessed the effectiveness of TNF antagonists combined with another medical or surgical intervention for PCD; or assessed the association between anti-TNF serum concentrations and fistula healing. Twelve studies compared anti-TNF therapy alone versus a combined approach: four with surgery, three with antibiotics, and five with immunomodulators. Only two studies, both with antibiotics, were rated high quality. The addition of antibiotics to anti-TNF therapy resulted in significantly higher rates of fistula response and healing in one study, and a trend toward reduction in fistula drainage in the other. Three of four studies found higher rates of fistula healing when surgery was combined with TNF antagonists. In contrast, one of five studies found a trend toward higher rates of fistula healing in patients treated concomitantly with immunomodulators. Five observational studies assessed the association between anti-TNF concentration and fistula healing. Higher infliximab serum concentrations were consistently associated with fistula healing. In conclusion, few high-quality studies assessing strategies to optimize anti-TNF therapy for PCD exist. Although antibiotics, possibly surgery, and higher serum infliximab concentrations appear to improve fistula healing, future prospective studies are needed to determine the optimal treatment strategy.

Dermatofibrosarcoma protuberans is a low-grade sarcoma typically originating in the dermis but with local invasion of subcutaneous cell and muscle tissue. We report a case of perianal dermatofibrosarcoma protuberans in a 41-year-old male complaining of anal pain and constipation. To date, only two cases of perianal dermatofibrosarcoma protuberans have been reported. The unusual location hinders surgical treatment. The characteristic translocation t(17;22)(q22;q13) leading to the formation of COL1A1/PDGFβ fusion transcripts is not only of diagnostic value but also enables an alternative imatinib-based therapy in inoperable or metastatic cases. The pertinent literature is reviewed.

Plexiform schwannoma is an extremely rare variant of schwannoma, accounting for approximately 5% of cases. Due to the rarity and lack of typical symptoms, signs and radiological images, a definite diagnosis of plexiform schwannoma may not be made by clinicians prior to biopsy. In the present study, we report the first case (to our knowledge) of perianal plexiform schwannoma arising from the overlapped skin of the ischioanal fossa, and we propose an intratumorally nonenhanced circumferential capsule dividing the tumour into multiple homogeneously enhanced nodules as a magnetic resonance imaging feature to aid in the differential diagnosis of plexiform schwannoma from ancient schwannoma, cavernous haemangioma, liposarcoma and plexiform neurofibroma.