Testicular Adrenal Rests Tumors
Imaging plays an important role in the detection and surveillance of testicular adrenal rest tumors.
Ultrasound (US) is generally considered the first imaging modality for evaluation of TART.
Ultrasound
Ultrasound usully demonstrated hypoechogenic,
intratesticular masses,
usually with ill-defined borders and in most cases bilateral.
Typically these masses are located near the mediastinum testis.
(Fig 1)
Testicular adrenal rests tumor varies in size,
from millimeters to a few centimeters (commonly 3 to 40 mm),
however they usually dont cause architectural distortion of the surrounding testicular parenchyma or deformation of the testicular morphology.
(Fig 2)
Fig. 1: Testicular adrenal rests tumors. 3 months old male with CAH. Sagittal US images demonstrated a small nodular hypoechogenic intratesticular lesion, near the mediastinum testis, that present increased vascularity on color-Doppler sonographic evaluation compared to the adjacent testicular parenchyma. The patient had ACTH serum level: 499,0 pg/mL (normal < 46,0 pg/mL); cortisol serum level: <1 μg/dL (normal 5 to 25 μg/dL).
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Fig. 2: Testicular adrenal rests tumors. 16-year-old male with poorly controlled CAH was referred for evaluation due to testicular pain and bilateral palpable mass. (A) Axial and (B-C) sagittal US images demonstrated bilateral nodular hypoechogenic intratesticular masses, located around the mediastinum.
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
In some cases,
few of the lesions can present acoustic shadowing.
(Fig 3)
Fig. 3: Testicular adrenal rests tumors. 17-year-old male with CAH was referred for routine evaluation. At physical examination testicular size was normal, there was no palpable masses. (A) Axial and (B-C) sagittal ultrasonographic images demonstrated bilateral nodular hypoechogenic intratesticular masses, located around the mediastinum testis that determine slight acoustic shadowing.
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Testicular adrenal rests tumors usually present a slightly increased vascularity compared to the normal testicular parenchyma at color-Doppler sonography.
(Fig 1,
4 and 5)
Fig. 4: Testicular adrenal rests tumors. 16 years old male with CAH. (A) Axial and (C) sagittal ultrasonographic images demonstrated bilateral nodular hypoechogenic intratesticular masses, characteristically located around the mediastinum testis. At (B) color-Doppler evaluation, the TART have slightly increased vascularity compared to the adjacent normal testicular parenchyma.
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Fig. 5: Testicular adrenal rests tumors. 3 years old male with CAH. (A) Axial and (B) sagittal ultrasonographic images demonstrated bilateral nodular hypoechogenic intratesticular masses, characteristically located around the mediastinum testis. At (C) power-Doppler US evaluation, the testicular adrenal rests tumors show increased vascularity compared to the adjacent parenchyma.
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Although the testicular adrenal rests tumors are usually hypoechogenic,
lesions larger than 2 cm can be heterogeneous,
sometimes hyperechogenic,
and may present calcifications.
(Fig 6)
Fig. 6: Testicular adrenal rests tumors. 24 years old male with CAH. (A) Axial and (C-D) sagittal US images obtained in three different locations demonstrated bilateral nodular heterogeneous intratesticular masses, with calcifications
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Testicular adrenal rests tumors have no malignant features.
However,
because of the localization near the mediastinum testis, compression of the seminiferous tubules might lead to significant damage of the surrounding testicular tissue,
leading to infertility.
(Fig 7)
Fig. 7: Ectasia of the rede testis in a patient with CAH and testicular adrenal rest tumors
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Testicular adrenal rest tumours in CAH might impair both spermatogenesis and endocrine testicular function,
resulting in infertility.
Poor controlled disease,
resulting in elevated ACTH serum levels is thought to induce the TART growth.
However,
the association of TART and disease control is not entirely undestood.
Some individuals might present increase in TART despite good disease control parameters.
(Fig 9 and 10)
Fig. 9: Testicular adrenal rests tumors. 16 months old male with CAH. (A) Axial and (B) sagittal images demonstrated bilateral nodular heterogeneous intratesticular masses, near the mediastinum testis, with slightly increased vascularity on color-Doppler evaluation. ACTH serum level: 40,0 pg/mL (normal < 46,0 pg/mL); cortisol serum level: <1 μg/dL (normal 5 to 25 μg/dL).
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Fig. 10: US evaluation of the same individual depicted in Fig 9, after two years, shows a significant increase in size of the bilateral lesions, despite the good clinical treatment control. ACTH serum level: 31,0 pg/mL (normal < 46,0 pg/mL); cortisol serum level: 1,2 μg/dL (normal 5 to 25 μg/dL).
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
MR Imaging
Testicular adrenal rests tumor appear homogeneous on both T1- and T2-weighted MR images.
TART are commonly isointense,
eventually hyperintense,
to normal testicular tissue on T1-weighted MR images and hypointense on T2-weighted MR images.
TART are isointense to muscle tissue on both T1- and T2-weighted MR images,
similar to MR appearance of the normal adrenal glands.
In most cases,
these lesions enhance after gadolinium administration.
Currently the diagnosis of CAH is generally established by neonatal screening programs.
However,
in individuals with milder forms of the disease the accurate diagnosis may not be established until late childhood or even early adulthood. (Fig 11 and 12)
Fig. 11: Testicular adrenal rests tumors. 45-year-old male referred for evaluation due to testicular palpable right testicular mass. US evaluation demonstrated bilateral heterogeneous, intratesticular, ill-defined masses, located around the mediastinum testis, that determine slight acoustic shadowing.
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
Fig. 12: Testicular adrenal rests tumors. MR imaging of the same individual depicted in Fig 11 (A) On axial T1-weighted MR images the lesions are isointense relative to the testicular parenchyma. (B and D) Axial and sagittal T2-weighted MR image show a lobulated intratesticular lesion that is hypointense compared with normal testicular parenchyma. (C) Enhanced sagittal T1-weighted MR image shows slight homogeneous enhancement of the intratesticular lesions.
References: Department of Radiology, Clinics Hospital, University of São Paulo, SP, Brazil
The main differential diagnosis is with Leydig cell tumor and lymphoma.