Intratesticular Mass



Intratesticular Mass


Bhawan K. Paunipagar, MD, DNB

Michael P. Federle, MD, FACR



DIFFERENTIAL DIAGNOSIS


Common



  • Epididymitis/Orchitis


  • Testicular Carcinoma


  • Testicular Torsion/Infarction


  • Testicular Hematoma


Less Common



  • Testicular Abscess


  • Testicular Lymphoma and Metastases


  • Gonadal Stromal Tumors, Testis


  • Testicular Epidermoid Cyst


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Age and clinical presentation


  • Sonographic findings are key (but overlap among various tumors)



    • Histopathological correlation is needed


Helpful Clues for Common Diagnoses



  • Epididymitis/Orchitis



    • Epididymis is primarily involved in epididymo-orchitis



      • Orchitis is usually secondary, occurring in 20-40% cases with epididymitis due to contiguous spread of infection


      • Primary orchitis is caused by mumps and is usually bilateral


    • Orchitis is characterized by inflammation, edema, and swelling of testis



      • Diffuse orchitis: Testis is diffusely enlarged with heterogeneous echo pattern


      • Focal orchitis: Hypoechoic focal area, usually adjacent to the inflamed epididymis


    • Increase in vascularity on color Doppler, without displacement of vessels


  • Testicular Carcinoma



    • Best diagnostic clue: Discrete hypoechoic or mixed echogenic testicular mass, ± vascularity



      • Tumor < 1.5 cm is commonly hypovascular


      • Tumor > 1.6 cm is more often hypervascular


      • Discrete mass on grayscale ultrasound with abnormal intrinsic vascularity on color Doppler should raise suspicion of a testicular carcinoma


    • Seminoma



      • Most common neoplasm in males between ages 15-39 years


      • Well-defined, lobulated, hypoechoic solid lesion without calcification or tunica invasion


      • May undergo necrosis and appear partly cystic


    • Teratoma/teratocarcinoma



      • Heterogeneous, complex, solid/cystic mass


      • Calcification (cartilage, immature bone) ± fibrosis characterize teratoma/teratocarcinoma


    • Embryonal cell carcinoma



      • Heterogeneous, predominantly solid, mixed echogenicity mass


      • Poorly marginated, 1/3 have cystic necrosis


      • May invade the tunica albuginea and distort testicular contour


    • Choriocarcinoma



      • Mixed echogenicity, heterogeneous mass


      • Cystic areas and calcification common


      • Hemorrhage with focal necrosis is typical feature of choriocarcinoma


      • May sometimes invade the tunica albuginea


      • Proclivity for early hematogenous spread, especially to brain


  • Testicular Torsion/Infarction



    • Acute pain, no history of trauma, in patients in hypercoagulable states or with advanced atherosclerosis such as diabetes


    • Diffusely hypoechoic small testis/focal mass in infarcted testis


    • Hyperechoic regions (hemorrhage/fibrosis), focal infarctions may have linear appearance


    • Segmental infarction may be a sequela of inflammatory process (orchitis)


  • Testicular Hematoma



    • Indicated by focal hypoechoic area within the testis, history of scrotal trauma


    • Abnormal testicular parenchymal echogenicity, avascular mass; echogenicity depends on the age of the hematoma


    • Discrete linear or irregular fracture plane within testis



    • Distorted intratesticular vascularity with interruption of vessels in the area of hematoma or injury


Helpful Clues for Less Common Diagnoses



  • Testicular Abscess



    • Epididymal abscess = 6%, testicular abscess = 6%


    • Microabscess formation is usually seen in low-grade infections (e.g., tuberculosis) and in immunocompromised host


    • Well-defined, discrete, rounded, hypoechoic lesion/lesions in the testicular parenchyma


    • Necrotic center shows no vascularity on color Doppler studies


  • Testicular Lymphoma and Metastases



    • Lymphoma



      • Most common testicular tumor in men > 60, multiple lesions; 50% of cases bilateral


      • Often large in size at the time of diagnosis, commonly occurs in association with disseminated disease


      • Ill-defined, predominantly hypoechoic lesions


      • Very vascular on color Doppler


      • Involvement of epididymis and spermatic cord is common; hemorrhage or necrosis is rare


    • Metastases are rare; most common sites include prostate, lung, and GI tract


    • Testis is a frequent site of relapse in male patients with acute leukemia


  • Gonadal Stromal Tumors, Testis



    • Bilateral in 3%



      • < 3 cm usually benign


      • > 5 cm malignant


    • Leydig cell tumor



      • Small solid hypoechoic testicular mass


      • In larger tumor hemorrhage or necrosis leads to heterogeneous echo pattern


    • Sertoli cell tumor



      • Small hypoechoic mass, solid and cystic components


      • Punctate calcification may be present; large calcified mass in calcifying Sertoli cell tumor


      • Hemorrhage may lead to heterogeneity


    • Indistinguishable from other testicular tumors by ultrasound findings


  • Testicular Epidermoid Cyst



    • Cystic cavity lined by stratified squamous epithelium


    • “Onion skin” appearance on US due to alternating layers of keratin and desquamated squamous cells


    • May have peripheral calcified rim



SELECTED REFERENCES

1. Dogra V et al: Acute painful scrotum. Radiol Clin North Am. 42(2):349-63, 2004

2. Woodward PJ et al: From the archives of the AFIP: tumors and tumorlike lesions of the testis: radiologic-pathologic correlation. Radiographics. 22(1):189-216, 2002

Aug 2, 2016 | Posted by in GENERAL | Comments Off on Intratesticular Mass
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