V25 - Internal Capsulectomy for Rare Perianal Cyst

Saturday, May 9, 2026

On-Demand

Video Presentation(s)

TONG SU, 在读状态 (she/her/hers)

graduate student
上海中医药大学附属龙华医院
上海中医药大学附属龙华医院
上海市, Shanghai, China (People's Republic)

All disclosed relationships have been reviewed and managed prior to the start of this activity. Any relevant relationships will be listed below. This individual has no financial relationships to disclose

Author(s)

xw

xingchen wang, N/A

Doctoral student
Longhua Hospital Shanghai University of Traditional Chinese Medicine
shanghai, Shanghai, China (People's Republic)

Disclosure information not submitted.
ZHIYONG MAO

Resident
Longhua Hospital Affiliated to Shanghai University of Traditional Chinese Medicine
shanghai, Shanghai, China (People's Republic)

Disclosure information not submitted.
YAN PAN, Master's degree

Graduate Student
Longhua Hospital Affiliated with Shanghai University of Traditional Chinese Medicine
Shanghai University of Traditional Chinese Medicine
SHANGHAI, Shanghai, China (People's Republic)

Disclosure information not submitted.
QD

QINGJUN DONG, Chief physician

Deputy Director of the Department
Anorectal surgery department, Longhua hospital of shanghai university of TCM
shanghai, Shanghai, China (People's Republic)

Disclosure information not submitted.

CME Eligible

Purpose/Background: Perianal breast-type myofibroblastoma is an exceptionally rare benign mesenchymal neoplasm, with only a handful of cases reported worldwide. Owing to its deep anatomical location and complex perianal structure, optimal surgical management remains challenging. This paper introduces a novel Internal Capsulectomy , emphasizing how precise anatomical-plane surgery can enhance outcomes for such rare perianal lesions.

Methods/Interventions: A 59-year-old male presented with a painless, slowly enlarging left gluteal mass persisting for over one month. Physical examination revealed an 8 × 5 cm firm, well-circumscribed, and moderately mobile lesion. Pelvic MRI demonstrated a cystic mass within the left ischiorectal fossa. The surgical approach employed endoscopic intercapsular dissection, following the natural plane between the capsule and surrounding tissue, using a combination of sharp and blunt dissection. Wound management integrated negative-pressure drainage and full-thickness layered suturing. Postoperative care included antibiotic prophylaxis, progressive dietary advancement, bowel regulation, and scheduled suture removal on postoperative days 10 and 17.

Results/Outcomes: Complete en bloc excision was achieved while preserving capsular integrity. The resected specimen measured 80 × 60 × 40 mm, weighing 120 g, with an additional 60 × 60 × 8 mm adipose-muscular component. Histopathology confirmed a breast-type myofibroblastoma composed of spindle cells arranged in short fascicles within a myxoid stroma. Immunohistochemistry was positive for CD34 and desmin. The patient recovered uneventfully, resumed a regular diet within seven days, and exhibited minimal drainage. Follow-up MRI at three months demonstrated excellent healing and no recurrence.

Conclusion/Discussion: Internal Capsulectomy provides a minimally invasive, anatomically precise, and hemostatically controlled solution for rare perianal tumors. When combined with contemporary wound management, this technique ensures optimal healing and complete lesion clearance. This case highlights a practical paradigm for the management of deep perianal pathologies through preservation of natural tissue planes and multidisciplinary postoperative care.

Internal Capsulectomy

Surgical Specimen and Pathological Analysis