Scrotal masses, whether cystic or solid lesions, are routinely evaluated using ultrasonography. Magnetic resonance imaging (MRI) may be used for further investigation in cases with atypical findings, difficult diagnoses, large masses, and/or unclear relationships with the surrounding tissues. Scrotal solid masses are divided into intra- and extra-testicular masses. A staggering 90% of the intratesticular masses are malignant, whereas 75% of extratesticular masses are benign. Extratesticular masses are less common than intratesticular masses; however, some extratesticular masses present characteristic MRI findings. Familiarity with these specific MRI features of extratesticular masses is beneficial to radiologists, as appropriate diagnoses can help avoid unnecessary invasive treatments such as orchiectomy. In this review, we describe fibrous pseudotumors, polyorchidism, adenomatoid tumors, and scrotal leiomyoma as benign paratesticular masses, focusing on their characteristic imaging features on MRI. Although these tumors are extremely rare, their MRI findings are distinctive, and accurate diagnoses can prevent unnecessary orchiectomy. In addition, to demonstrate the pitfalls of diagnosing extratesticular masses, we present a case of seminoma misidentified as extratesticular masses due to large extensions outside the testis. Spermatic cord sarcoma, including rhabdomyosarcoma, leiomyosarcoma, and liposarcoma, and metastasis to the spermatic cord are described as malignant extratesticular masses. This review focused on extratesticular masses and elaborates the imaging findings that can aid in the accurate diagnosis using MRI.

Paratesticular embryonal rhabdomyosarcoma (RMS) is a very rare and aggressive mesenchymal tumor. It is usually seen in children and adolescents presenting as a painless intrascrotal mass, localized in the paratesticular region. Hereby, we report two cases of paratesticular embryonal RMS in adults. One case was clinically suspected to be a testicular abscess, whereas the other presented with testicular swelling and lung metastasis. Localized forms have a good prognosis, whereas tumors presenting with metastases show a poor outcome. A treatment based on surgery and chemotherapy yields good results. Sperm cryopreservation and endocrine follow-up improve the overall survival and quality of life of these patients.

Paratesticular cystadenomas remain a very rare entity, typically presenting as a painless mass, often indistinguishable from the testicle. As such, the predominant management seems to be complete excision via various approaches, which often proves curative. Given its rarity, post-operative surveillance has not been standardized; most patients and providers elect a more conservative surveillance approach. Based on the available literature, this seems appropriate, given the lack of morbidity or recurrence associated with these types of tumors.

Paratesticular leiomyosarcoma is a rare urologic cancer that arises from undifferentiated smooth muscles of the spermatic cord or epididymis. Few accounts of this cancer have been reported but previous reports have identified radiation and anabolic steroids as possible risk factors. We report a case of an 83-year-old man with a previous history of radiation therapy for prostate cancer, who presented with a painless left scrotal mass. Given the nonspecific presentation, a histopathological classification was warranted for a definitive diagnosis. The tumor was resected via simple orchiectomy and was diagnosed as a paratesticular grade III leiomyosarcoma without any further treatment. Patient had a follow-up CT scan of the abdomen and pelvis that was normal without metastasis. The patient\'s history of previous external beam radiation and now development of a secondary tumor sums to the few cases that have been previously reported with this association.

Tumors of the para-testicular adnexa are very rare and are typically histologically diagnosed as adenomatoid neoplasms, leiomyomata, or smooth muscle hyperplasia. Though these masses are usually benign, the potential for malignancy and mass effect causing intrascrotal discomfort necessitate proper diagnosis and excision. Herein, we describe a unique case of gradual, atraumatic testicular dislocation in a 40-year-old male caused by smooth muscle hyperplasia of the testicular adnexa affecting the epididymis and vas deferens. This case highlights the diagnostic and surgical challenges associated with this presentation.

The majority of patients with paratesticular rhabdomyosarcoma (RMS) present in the pediatric age group with a unilateral, painless, palpable scrotum mass. By contrast, cases of RMS presenting as painful edema are rare. We present a case of alveolar paratesticular RMS in a 30-year-old man who had been suffering from a painful swelling of the scrotum on the left side for two years and a preceding mass four months before visiting the clinic. Complete resection of the left epididymal mass was performed through a left inguinal incision. The histopathological and immunohistochemical examination of the mass revealed alveolar RMS of the paratesticular region. Urologists should be aware that paratesticular RMS may present in adults with atypical symptoms such as scrotal pain and edema, especially in those who do not respond to antibiotics. Hence, such patients should have an additional evaluation.

Lipoblastomas are rare benign mesenchymal tumors comprised primarily mature adipocytes, which are most commonly found in infants and children younger than 3 years. They are usually found in the extremities, trunk, head, neck, and retroperitoneum, although cases occurring in the scrotum have been reported. Due to its rarity, there is a relative paucity of literature describing its imaging and management. We present a rare case of a scrotal lipoblastoma, and discuss the current imaging strategies to differentiate this adipocytic tumor from other more common paratesticular masses, including aggressive neoplasms such as rhabdomyosarcomas. Knowledge of the radiological appearance of lipoblastoma can provide the correct diagnosis and prevent unnecessary orchiectomy.

Aggressive angiomyxoma (AAM) is a rare mesenchymal myxoid tumor, and most cases occur in the pelvic region or perineum of adult females. AAM is very rare in males. Most of these cases have been diagnosed in patients aged 30-60 years, and the tumors involved the pelvic cavity, scrotum, or spermatic cord. AAM can mimic inguinal hernia, hydrocele, or paratesticular neoplasm. Four male cases have been reported with paratesticular AAM mimicking a testicular/epididymal tumor, and to the best of our knowledge, this is the oldest patient in the literature. Because of its rarity, making an exact diagnosis before surgery is difficult. Herein, we present a case of AAM in an 82-year-old man and review the literature.

The differential diagnosis of scrotal pain and swelling in adolescent males includes testicular and appendage torsion, epididymitis, epididymo-orchitis, trauma and incarcerated hernia. Physical examination, ultrasound and urinalysis often can identify the etiology of the scrotal pain and swelling. We present a case of left scrotal pain and swelling that was initially concerning for a paratesticular mass. Repeat examination and further imaging during pre-operative assessment was consistent with left-sided vasitis. The diagnosis of vasitis is difficult with ultrasound and commonly requires CT or MRI to differentiate from incarcerated inguinal hernia. Recognition of this uncommonly reported condition may prevent unnecessary surgeries.

Smooth muscle hyperplasia of the testicular adnexa (SMH-TA) is a rare mass-forming intrascrotal lesion. Although benign, it can be a diagnostic challenge, as we have seen in our consult practice. Herein, we discuss our experience with these lesions over 14 years. Twelve SMH-TA cases were identified in our institutional records between 2005 and 2019. The morphologic features were reviewed. Clinical information was obtained from physicians\' notes. The mean age was 51 years (range, 24-82 years). Six cases were on the left side, five on the right, and one was bilateral. The most common presentations were orchialgia (n = 10) and mass (n = 6). Two patients had a concurrent incarcerated inguinal hernia, and one had a recent groin trauma. Past medical history included 5 patients with previous surgeries in the inguinal region, 2 with a history of treated infections, and 1 with persistent chronic orchitis. Eight patients have undergone ultrasound imaging which showed lesions (n = 4), hematoma (n = 1), undescended testis (n = 1), or no abnormalities (n = 2). Grossly, the mean size was 1.7 cm (range, 1.0-3 cm). The lesions had ill-defined, focally cystic, pink-tan nodular surface. Microscopically, the lesions were comprised of an ill-defined smooth muscle proliferation arranged in fascicles or haphazard fashion, growing in a periductal, perivascular, interstitial, or most commonly in a mixed pattern. SMH-TA is a rare benign entity that can present clinically as orchialgia and/or a suspicious intrascrotal mass. As suggested in previous studies, we believe that this lesion represents a reactive process.