V. Kurbatov1, J. M. Bloom2, G. A. Yavorek1 1Yale University School Of Medicine,General Surgery,New Haven, CT, USA 2Southern Connecticut State University,New Haven, CT, USA
Introduction:
Cellular angiofibroma (CAF) was first described by Nucci et al in1997 as a distinctive mesenchymal neoplasm with 2 principal components: spindle cells and prominent vasculature. It was initially though to be a tumor of the vulva of middle-aged women. A histologically indistinguishable lesion called “angiomyofibroblastoma-like” tumor in the inguino-scrotal region of adult men was soon after described, broadening the WHO definition of CAF to include lesions in both genders. Extragenital locations have been described since, prompting Fletcher et al to publish a 51 case series of CAFs, describing a near equal distribution between men and women, with diverse distribution including spermatic cord, retroperitoneum, testis, urethra, perineum, vagina, vulva, and labium. One case of anal CAF was included. Median size was 2.7cm in females and 6.7cm in males. These cases followed benign course without recurrence after complete resection.
Subsequently, Fletcher et al described 13 cases of CAF with sarcomatous transformation. Patients were predominantly female with tumors of the vulva. Follow up information for 6 of 7 of the patients showed no evidence of recurrence after resection. One patient died 27 months after diagnosis of carcinoma of unknown primary. Cases with sarcomatous transformation appear to share p16 over-expression.
Methods:
We describe a case of 62 year old male with the first pathologic diagnosis of rectal CAF. We performed a review of clinical records and pathology, as well as extensive literature review.
Results:
The 62 year old male patient, with family history of prostate cancer, presented with a 1.4 cm submucosal rectal mass seen on surveillance MRI. EUS was performed, confirming the lesion, which increased in size to 1.6 cm in span of three months. A transanal excision was performed with resection of a 2cm mass.
Grossly, the tumor formed a well circumscribed nodule involving rectal submucosa and muscularis propria. Histologically, spindle cells were arranged in fascicles with intervening vessels and wispy collagen fibers. Immunostaining was positive for CD34 and ER and negative for Stat6, Cam5.2, S100, Desmin, PR, Dog1, SMA. Kit immunostain highlights numerous mast cells within the tumor. Mitotic activity was low. Immunohistochemical and morphologic features were consistent with CAF.
Conclusion:
The rectum is a potential site of CAF. Surgical resection with clear margins is the current treatment standard. Care needs to be taken to differentiate CAFs from angiomyofibroblastoma and aggressive angiomyxoma (AAM). These tumors share microscopic characteristics but have significantly different behavior. AAM is documented to be locally infiltrating with a 30% local recurrence rate despite wide local excision. Current literature suggests that this is not the case for CAF. Desmin can be used to distinguish between these lesions, as aggressive angiomyxoma, myofibroblastoma and angiomyofibroblastoma are positive for this antibody.