Benign Fibromatous Tumors of the Testis and Paratesticular Region: A Report of 9 Cases with a Proposed Classification of Fibromatous Tumors and Tumor-Like Lesions

Abstract

Benign intrascrotal fibrous proliferations are uncommon, with most arising from the paratesticular region and falling into the category of so-called fibrous pseudotumor. We describe two neoplastic forms of benign fibrous tumor of the testis and its adnexa: fibroma of gonadal stromal origin and fibroma of the testicular tunics. Three patients with gonadal stromal fibroma were 28, 33, and 35 years of age and presented with painless masses. The tumors were circumscribed, intratesticular, yellow-white or white lesions 0.9 to 4.0 cm in diameter and had microscopic features identical to those of the ovarian fibroma. Immunohistochemically, the tumor cells were strongly positive for vimentin (3/3 cases), focally positive for actin and desmin (2/3 cases) and negative for S-100, keratin, and CD34 (3/3 cases). Six fibromas of the testicular tunics arose in patients 22, 34, 60, 68, 70, and 74 years old and were also asymptomatic masses. Four of them were circumscribed, whorled, white masses arising from the tunica albuginea with variable areas of myxoid change; one was pedunculated and grew exclusively into the cavity of the tunica vaginalis, whereas the other three at least partially extended into the testis as well. The other two tumors were unattached to the tunica albuginea and presented as circumscribed, white-tan paratesticular masses, partially covered by tunica vaginalis. Microscopically, the tumors were slightly to moderately cellular, with bland spindle or stellate cells lying in a myxoid or collagenous stroma with prominent vessels. The two paratesticular tumors had features typical of solitary fibrous tumor. Immunohistochemically, the fibromas of the testicular tunics were negative for S-100, keratin, and desmin. Focal, weak reactivity for actin was present in one case. CD34 was positive in three cases; in the two tumors resembling solitary fibrous tumors it was strong, and in the other it was focal and was limited to the region just below the tunica vaginalis. Eight tumors were treated by radical orchiectomy and one by excision of the mass alone. The outcome was benign in the seven cases in which followup information is available.

Fibrous Pseudotumor of the Scrotum

“…Although the terminology, classification, and proposed pathogenesis have been confusing and controversial, these lesions are generally accepted to represent a benign reactive proliferation of inflammatory and fibrous tissue, likely in response to trauma, surgery, infection, or inflammation, as distinct from true benign fibrous neoplasms, which may also rarely occur in the testis and testicular tunics. 8 The pathology literature separates these reactive lesions into inflammatory and fibrous pseudotumors depending on the degree of cellularity, possibly representing early and later phases of a temporal spectrum of the same underlying process, 1 hence the pathologic designation of a burned-out inflammatory pseudotumor in our case, which represented a low to intermediate cellularity lesion. Fibrous pseudotumors have been reported over a very wide age range, with the most common occurrence variably described as in the third decade or third through sixth decades, but is very rare before 18 years.…”

“…Since an early reference to a case of a peritesticular fibromatous mass by Sir Astley Cooper in 1830 and a case report by Balloch in 1904, 1,2 various case reports and small series have been published in the urology, pathology, and radiology literature. [2][3][4][5][6] Multiple other names have been applied to this and related entities, including chronic proliferative periorchitis, fibromatous periorchitis, pseudofibromatous periorchitis, reactive periorchitis, an inflammatory pseudotumor, nodular and diffuse fibrous proliferation of the tunica, a benign fibrous paratesticular tumor, granulomatous periorchitis, nonspecific peritesticular fibrosis, a nodular fibropseudotumor, and proliferative funiculitis, [7][8][9][10][11] partly reflecting the variable and overlapping spectrum of pathologic findings and various etiologic theories. Although the terminology, classification, and proposed pathogenesis have been confusing and controversial, these lesions are generally accepted to represent a benign reactive proliferation of inflammatory and fibrous tissue, likely in response to trauma, surgery, infection, or inflammation, as distinct from true benign fibrous neoplasms, which may also rarely occur in the testis and testicular tunics.…”

Rare case of paratesticular solitary fibrous tumour (lipomatous hemangiopericytoma)

“…[5][6][7] Intrascrotal solitary fibrous tumours are uncommon, with only a few cases reported in the paratesticular region. [6][7][8][9][10][11] Histologically, these tumours have similar morphological features to those present elsewhere in the body. 7 Most solitary fibrous tumours are benign and present as well-circumscribed, slowly growing, painless masses.…”

Role of frozen section analysis of testicular/paratesticular fibrous pseudotumours: a five-case experience

“…5 Historically, fibrous pseudotumours have been referred to by multiple names including fibromatous periorchitis, nonspecific paratesticular fibrosis, nodular fibropseudotumour, reactive periorchitis, fibroma, fibrous pseudotumour, pseudofibromatous periorchitis, proliferative funiculitis and several others. 2,5,6 However, because some lesions lack inflammatory component and are not nodular, the less specific term "fibrous pseudotumour" was preferred. 5 Although fibrous pseudotumours are non-neoplastic lesions, many patients will undergo radical orchiectomy for suspicion of malignancy.…”

“…1,2,6 It is usually possible to distinguish between these entities via the morphological appearance of the lesion, in conjunction with immunohistochemical stains and the presence or absence of infiltration into the surrounding tissue. However, at the time of intraoperative FSA, it may be difficult to make a definitive diagnosis of fibrous pseudotumour on a limited specimen.…”