Embryologically, the mesoderm of the scrotum gives birth to various tissues; thus tumors arising from that area have high diversity, and confirming a safe diagnosis between a benign and malignant lesion is difficult. Cellular AF was first described in 1997 by Nucci et al.  as a distinctive, benign soft tumor of the vulva in women that is distinguishable from AMF. Later, in 1998, Laskin et al.  described the AMF-like tumor, namely, a mesenchymal tumor of the male genital tract resembling that described by Nucci et al. Finally, Iwasa and Fletcher  reported 51 cases of cellular AF occurring in both sexes and considered AMF-like tumors and cellular AFs to be similar entities. In that report, the patients' ages ranged from 22 to 78 years, with an average age of 53.5 years; the range of mass sizes was between 0.6 cm and 25 cm; and the primary location was in the subcutaneous tissue but was usually well marginated. The anatomic locations were most frequently the genital area (22 cases) in women and the inguinoscrotal area (19 cases) in men.
Histologically, the tumors are typically well circumscribed, quite cellular with spindle-shaped cells evenly distributed, and with short bundles of collagen. Less cellular areas are often associated with stromal edema or hyalinization, but significant pleomorphism and abnormal mitoses are absent. The numerous vessels observed are round, thick-walled, and hyalinized .
Immunohistochemical diagnostic procedures reveal that 60% of patients have slight expression of CD34 (vascular origin), 21% have spinal muscular atrophy (epithelial and/or glandular origin), and 8% reveal desmin (muscular origin) . In our patient, the mass was an AF of vascular origin as revealed by its histopathological immunochemistry (vimentin- and CD34-positive and actin-, desmin-, and S100P-negative).
The diagnostic imaging workup includes a CT scan without specific findings for this entity , while on MRI scans AF may be hyperintense on the T2-weighted phase, depending on its origin and tissue composition (fat tissue, collagen, and spindle cells), or may show intense enhancement due to its rich vascularity .
It may be difficult to distinguish cellular AF from other tumors of the scrotum on the basis of radiological data only. The differential diagnosis includes tumors of Schwann cells, perineuromas, spindle cell lipomas , aggressive angiomyxomas (AAMs) , AMFs , solitary fibrous tumors (SFTs) , spindle-cell liposarcomas , and leiomyomas. Based on imaging, the differential diagnosis can be narrowed down to AAM, AMF, and SFT as follows: (1) AAM has a highly infiltrative pattern of growth, lower cellularity, and lower vascular growth and displays high signal intensity on T2-weighted MRI scans; (2) AMF exhibits high signal intensity on T2-weighted MRI scans but may appear slightly inhomogeneous, and the radiologic findings may be similar to those of cellular AF; and (3) SFT exhibits low signal intensity to isointensity for muscle tissue on T1-weighted MRI scans, intermediate to high signal intensity on T2-weighted MRI scans, and intense enhancement on gadolinium injection scans.
Surgical resection of the tumor is the therapeutic method of choice. Unfortunately, follow-up clinical data for cellular AF is limited, although recurrences have been reported . A complementary resection must follow initial local excision if the tumor relapses.