Anal leiomyoma Aras Emre Canda, MD,a Sulen Sarioglu, MD,b and Selman Sokmen, MD,b Izmir, Turkey
From the Department of Surgery,a and the Department of Pathology,b School of Medicine, Dokuz Eylul University, Izmir, Turkey
A 37-YEAR-OLD MAN was admitted to our institution with a gradually enlarging anal mass that had been developing for 5 months. He had no symptoms of anal bleeding, pain, or constipation and no past medical history. Clinical examination revealed a firm perianal mass under the anal mucosa and skin (Fig 1). The stalk of the lesion felt mobile on the anal sphincters. Complete local excision of the subcutaneous and submucosal lesion was performed with spinal anesthesia at lithotomy position. Macroscopically, the lesion was solid, firm, lobulated, and encapsulated. The tumor measured 8 3 4 cm. The operative margins were negative and there was no mucosal or sphincter invasion. Histopathologic examination revealed a spindle cell tumor without cytological atypia or necrosis and low mitotic activity (1 mitosis/50 high-power fields; Fig 2). The tumor cells were positive for smooth muscle markers desmin, a-smooth muscle actin, and caldesmon, and negative for CD117, CD 34, and S100 by immunohistochemical examination. The final diagnosis was leiomyoma. DISCUSSION Leiomyoma of the anorectal region are exceedingly rare, benign tumors with an estimated incidence of <0.1% of all anorectal neoplasms.1,2 They may arise from the muscularis mucosa, muscularis propria, or sphincter muscles in the anorectal region.3 Differentiation of anal leiomyomas from other spindle cell tumors, especially anal and gastrointestinal stromal tumors (GISTs) calls for particular attention; leiomyosarcomas and GISTs require radical operative excision with or without adjuvant treatment and close follow-up. Macroscopically,
Fig 1. Tumor under the anal mucosa and skin.
Fig 2. Encapsulated tumor composed of spindle cells (hematoxylin and eosin; original magnification, 3 10).
Accepted for publication February 23, 2009. Reprint requests: Aras Emre Canda, MD, 217 sok. No:23/8 Bornova, Izmir 35040, Turkey. E-mail: [email protected]
. Surgery 2010;148:160-1. 0039-6060/$ - see front matter Ó 2010 Mosby, Inc. All rights reserved. doi:10.1016/j.surg.2009.02.009
ulceration of the overlying mucosa may both occur in leiomyomas, leiomyosarcomas, and GISTs. Histopathologically, all the 3 entities are spindle cell tumors. The high mitotic activity and necrosis are usually present in leiomyomas and GISTs. Immunohistochemically, leiomyomas and leiomyomas
Canda, Sarioglu, and Sokmen 161
Surgery Volume 148, Number 1
are positive for smooth muscle markers, whereas GISTs are positive for CD117 and/or CD 34, and/ or some smooth muscle markers like aktin and, rarely, desmin.4 Because physical examination and histopathologic features of the patient revealed leiomyoma, operative removal of the lesion with negative margins was considered to be adequate treatment. Incomplete initial resection is the leading cause of recurrence in patients with leiomyomas2; complete operative removal should be the treatment goal with extended follow-up.
REFERENCES 1. Walsh TH, Mann CV. Smooth muscle neoplasms of the rectum and anal canal. Br J Surg 1984;71:597-9. 2. Hatch KF, Blanchard DK, Hatch GF III, Wertheimer-Hatch L, Davis GB, Foster RS Jr, et al. Tumors of the rectum and anal canal. World J Surg 2000;24:437-43. 3. Kusminsky RE, Bailey W. Leiomyomas of the rectum and anal canal: report of six cases and review of the literature. Dis Colon Rectum 1977;20:580-99. 4. Miettinen M, Furlong M, Sarlomo-Rikala M, Burke A, Sobin LH, Lasota J. Gastrointestinal stromal tumors, intramural leiomyomas, and leiomyosarcomas in the rectum and anus: a clinicopathologic, immunohistochemical, and molecular genetic study of 144 cases. Am J Surg Pathol 2001;25:1121-33.