MR Imaging of the Testicular and Extratesticular Tumors: When Do We Need?

A case of intrascrotal extratesticular schwannoma

Schwannomas are benign tumors arising from Schwann cells, which compose the myelin sheath covering peripheral nerves. Although schwannomas can develop in various locations throughout the human body, the scrotum is a rare site for development of a schwannoma. Furthermore, to the best of our knowledge, no study to date has focused on the detailed imaging findings of intrascrotal schwannoma.

[Magnetic resonance imaging accuracy and utility for testicular cancer diagnosis]

PURPOSE

The purpose of our study is to analyze the imaging findings described in MRI and the histopathologic type of testicular lesions to determine which findings are the best predictors of malignancy.

MATERIALS AND METHODS

Forty six (46) patients with testicular lesions were initially studied with ultrasound (US) and with testicular MRI (tMRI) on a 1.5-T magnet. MRIs were reviewed by a radiologist with 8 years of experience and imaging findings such as the size of the lesion, the signal intensity in T1, T2 weighted sequences, and the enhancement after endovenous contrast administration, were correlated with the histopathologic diagnosis. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were analyzed.

RESULTS

The enhancement after administration of contrast was the finding of better performance with a sensitivity, specificity, PPV and NPV of 90 (71-97), 47 (24-71), 74 (56-87) and 73 (40-92), respectively. Meanwhile, the results for hypointense/heterogeneous lesions in T2 weighted sequences and with enhancement with intravenous contrast were 87 (49-84), 47 (44-89), 74 (55-86) y 67 (35-89), respectively.

CONCLUSION

The finding of a testicular lesion of low signal intensity and heterogeneous in T2 weighted sequences, with IV contrast enhancement represents a valuable predictor of malignancy. The latter being the most sensitive as a predictor of malignancy.

Proton MR Spectroscopy in Assessing the Biochemical Milieu of Human Testes

Proton magnetic resonance spectroscopy (MRS), considered a connection between metabolism and anatomic and functional information provided by standard MRI, gives information on various tissue metabolites and their pathologic changes. Recently, proton MRS has been added as an adjunct tool to the multiparametric protocol of scrotal MRI, providing a new insight into the extremely complex biochemical milieu of normal and abnormal testes. This article reviews proton MR spectra of normal testes, showing age and bilateralism dependence. Disturbances of various metabolic pathways in testes of infertile men resulting in alterations of metabolite peaks are discussed. Preliminary data on proton MR spectra of testicular mass lesions are presented. LEVEL OF EVIDENCE: 5. TECHNICAL EFFICACY STAGE: 5.

Imaging of scrotal masses

Testicular cancer is responsible for approximately 0.1% of all cancer deaths in the USA, and seminoma is the most common type of testicular tumor. Ultrasonography is the primary imaging modality for accessing testicular and extratesticular lesions, while magnetic resonance imaging can be used for problem solving in lesion characterization in certain cases. CT imaging is usually performed for retroperitoneal staging of testicular cancer metastasis and follow-up after treatment. Extratesticular masses are common, yet rarely malignant. Imaging plays an important role in primary diagnosis of testicular cancer and differentiating it from common non-neoplastic findings. The purpose of this article is to review various imaging findings in testicular and extratesticular masses.

A case of inguinal cellular angiofibroma

INTRODUCTION

Cellular angiofibroma is a benign mesenchymal tumor that is rare and has a good prognosis. However, preoperative distinction of cellular angiofibroma from malignant tumors is difficult.

CASE PRESENTATION

A 77-year-old man complained of a left inguinal mass, which was a solid, painless, mobile tumor measuring approximately 40 mm and contacted with the left spermatic cord. Based on his age, the location and imaging findings, a preoperative diagnosis of myxoid liposarcoma was made. The patient underwent left high inguinal orchiectomy with complete resection of the tumor. Histologically and immunohistochemically, the tumor had no feature of malignancy. A postoperative diagnosis of cellular angiofibroma was made. The patient remains free of disease recurrence 12 months after surgery.

CONCLUSION

Cellular angiofibroma is a benign but rare tumor, which is sometimes difficult to distinguish from malignant neoplasms. Further studies are needed to accurately preoperatively diagnose this tumor.

Intrascrotal lipoblastoma in adulthood

This case report describes the case of a 37-year-old man that noticed an intrascrotal right mass with 1 month of evolution. During physical exam presented with a large mass at the inferior portion of the right testicle, clearly separated from the testicle, with a tender consistency and mobile. An ultrasound was performed that showed a solid and subcutaneous nodular lesion, extra testicular, heterogeneous, measuring 7.2 cm. Pelvic magnetic resonance imageMRI showed a lesion compatible with a lipoma. The patient was subjected to surgical excision of the lesion by scrotal access, having histology revealed a lipoblastoma (LB) of the scrotum. Histological diagnosis was obtained by microscopic characteristics (well-circumscribed fatty neoplasm) and immunohistochemistry (stains for CD34, S100 protein and PLAG1 were positive; stains for MDM2 and CDK4 were negative). LB is extremely rare after adolescence in any location, being this first described case of intrascrotal LB described in adulthood.

Infantile synchronous primary bilateral testicular germ cell tumor: a case report and review of the literature

Testicular tumors are uncommon in adults, accounting for <1% of all cancers, with testicular germ cell tumors (TGCTs) representing the majority (>95%) of reported cases. Adult and prepubertal TGCTs are fundamentally distinct and the latter is extremely rare, representing 1% of all pediatric solid tumors and having an annual incidence rate of 0.5-2/100,000 boys. Bilateral TGCTs (BTGCTs) account for 0.5-5% of all testicular tumors; the majority are metachronous, while the synchronous account for approximately 0.5-1%. A 16-month-old boy was admitted to our Urology Department with a 2-week history of a painless scrotal mass. Ultrasonography revealed a homogeneous hyperechoic solid mass with rich blood supply in the right testis, and no discernable testicular tissue. A well-delineated heterogeneous echo mass was found within the left testis. Contrast-enhanced computed tomography (CT) scan showed a significantly enhanced mass in the right testis and a mildly enhanced mass in the left testis. Serum alpha-fetoprotein (AFP) was 12,567 ng/mL, while β-human chorionic gonadotrophin (HCG) and total testosterone levels were normal. Accordingly, bilateral testicular tumors were the primary consideration. The patient underwent right radical inguinal orchiectomy with high ligation of the spermatic cord and left testicle-sparing surgery. Final pathology confirmed a pure yolk sac tumor (YST) from the right testis and a cystic mature teratoma from the left. The follow-up ultrasonography showed no recurrence, with serum AFP returned to normal by postoperative day 44. Synchronous primary BTGCT with teratoma and YST respectively can occur coincidently and successfully treated by testicle-sparing surgery.