Although rare, paratesticular inflammatory myofibroblastic tumor (IMT) represents the second most common paratesticular mass after adenomatoid tumor and comprises roughly 6% of such lesions. Only approximately four cases have been reported in patients younger than 18 years of age. We report an incidentally discovered paratesticular IMT in a 17-year-old male successfully treated with wide excision and testis sparing. To our knowledge, no recurrence has been reported after complete excision of paratesticular IMT; however, continued follow-up is recommended.
Inflammatory myofibroblastic tumor (IMT) is an uncommon spindle tumor that may arise in multiple anatomic sites, including the lung, gastrointestinal tract, retroperitoneum, central nervous system, extremities, and the genitourinary tract. Although rare, paratesticular IMT represents the second most common paratesticular mass after adenomatoid tumor and comprises approximately 6% of such lesions [
We report an incidentally discovered paratesticular IMT in a 17-year-old male treated with wide excision and testis sparing.
A 17-year-old male was referred for urologic evaluation of a right paratesticular mass noted on routine physical examination by his pediatrician. The patient had a history of congenital adrenal hyperplasia, treated with dexamethasone. He had not noticed any scrotal masses and denied any scrotal pain, swelling, or discomfort. The patient denied any history of dysuria, hematuria, urinary tract infection, or sexually transmitted diseases. No history of trauma, fevers, or any other constitutional symptoms was elicited.
Physical examination revealed Tanner stage 5 genitalia with a circumcised phallus and normal urethral meatus. Both testes were descended and were symmetric and nontender, with no intratesticular masses. A nontender, firm 0.8 cm mobile mass was palpated superior to the right testicle and was noted to be completely separate from the testis. Scrotal examination was otherwise normal. The patient had no inguinal lymphadenopathy bilaterally, and his abdominal examination was normal.
Scrotal sonography confirmed a 0.7 × 0.8 × 0.6 cm hypoechoic, vascular, slightly heterogeneous lesion superior to the right testicle (Figure
Scrotal sonogram demonstrating a 0.7 × 0.8 × 0.6 cm hypoechoic, vascular, heterogeneous lesion superior to the normal right testicle.
Despite a low suspicion for malignancy, surgical exploration was performed through a right inguinal approach with proximal control of the spermatic cord. The lesion was identified superior to the right epididymis and was noted to be mobile and completely separate from the epididymis, vas deferens, and testis (Figure
Intraoperative photograph demonstrating complete mobilization of the right spermatic cord, with proximal control achieved with a Penrose drain. The paratesticular lesion is depicted superior to the right epididymis, with a moderate amount of fat surrounding the mass.
Final gross pathologic analysis revealed a white, smooth nodule measuring 1.3 × 0.6 × 0.3 cm (Figure
Excised, bivalved lesion revealing a white, smooth nodule measuring 1.3 × 0.6 × 0.3 cm with surrounding fat.
Microscopic low-power (a) and high-power (b) views demonstrating fibrous proliferation (pink staining) and lymphoplasmacytic infiltrate (blue staining), with no cytologic atypia, mitotic activity, or necrosis.
The patient recovered uneventfully. Physical examination three months postoperatively revealed a well-healed incision and no evidence of recurrence.
IMT is a rare spindle tumor that has been assigned many names, including inflammatory pseudotumor, plasma cell pseudotumor, xanthomatous pseudotumor, atypical myofibroblastic tumor, atypical fibromyxoid tumor, pseudosarcoma, plasma cell granuloma, and fibrous pseudotumor [
IMT is the second most common paratesticular mass after adenomatoid tumor and comprises about 6% of paratesticular lesions [
Grossly, IMT is typically a circumscribed, firm, gray-white or yellow lesion [
The etiology of IMT remains unclear. It is postulated that these lesions may represent an exaggerated reparative response to trauma, chronic irritation, or infection [
A neoplastic etiology is suggested in some cases that demonstrate genetic aberrations in the short arm of chromosome 2 in region p21–p23, involving a 2p23 rearrangement in the
Some pseudotumors demonstrate elevated levels of intralesional IgG4-expressing plasma cells. Thus, it has also been proposed that IMT may represent a localized form of IgG4-related sclerosing disease, which refers to a group of disorders characterized by chronic fibroinflammatory processes at various anatomic sites [
Scrotal ultrasonography is usually the initial diagnostic modality and assists in distinguishing between an intratesticular versus extratesticular lesion as well as a solid versus cystic mass. IMT may appear as a hypoechoic or hyperechoic lesion, depending on its degree of collagen, calcifications, or fibroblasts [
Radiologic studies usually cannot differentiate between benign and malignant lesions; therefore, wide surgical excision is the treatment of choice for paratesticular IMT, with testis sparing when possible. Frozen section assessment is useful for intraoperative decision making. A recent study demonstrated that frozen section assessment aided in preventing unnecessary radical orchiectomy in 36 out of 43 (83.7%) benign testicular and paratesticular lesions [
Prognosis after complete surgical resection of paratesticular IMT is excellent. Recurrence rates of 23% to 37% have been reported in abdominal and retroperitoneal IMT [
Although rare, IMT should be considered in the differential diagnosis of paratesticular lesions. The treatment of choice is wide excision with testis sparing when possible; however, preoperative counseling should address the possibility of radical orchiectomy. Frozen section assessment is useful for intraoperative decision making. Prognosis after complete excision of paratesticular inflammatory pseudotumor is excellent. To our knowledge, no recurrence has been reported; however, continued follow-up is recommended.
Inflammatory myofibroblastic tumor
Anaplastic lymphoma kinase.
John H. Makari, MD, is investigator at Pfizer, Inc.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors would like to thank Boulos Beshai, MD, from the Hartford Hospital Department of Pathology and Laboratory Medicine for providing the histopathologic images for this paper.