Diagnostic ultrasound ( PDFDrive )

CHAPTER 52 The Pediatric Urinary Tract and Adrenal Glands 1827
A B C
FIG. 52.75 Pheochromocytoma in 6-Year-Old Boy With von Hippel-Lindau Syndrome and Bilateral Adrenal Pheochromocytoma. (A)
Longitudinal gray-scale image of the left lank reveals the presence of a solid, round adrenal mass (A) medial to the left kidney (LK). (B) Transverse
gray-scale image demonstrates a solid, rounded mass (arrow) medial to the right kidney (KID). L, Liver. (C) Iodine-123 metaiodobenzylguanidine
(MIBG) image fused to an intravenous axial contrast-enhanced computed tomography image depicts the bilateral adrenal tumors (arrows). The
right-sided mass shows greater radiopharmaceutical uptake than the left-sided mass.
A B C
FIG. 52.76 Adrenal Carcinoma in 8-Month-Old Girl With Virilization and Precocious Puberty. (A) and (B) Transverse and longitudinal
gray-scale images of the left lank demonstrate a large, round, heterogeneous mass replacing the adrenal gland. K, Left kidney. (C) Intravenous
contrast-enhanced axial computed tomography image shows the left adrenal mass (M) displacing and rotating the left kidney (arrow).
Masses generally range from 2 to 5 cm in diameter at presentation,
although they may exceed 10 cm. Larger lesions tend to be
heterogeneous as a result of hemorrhage, necrosis, and/or calciication
(Fig. 52.75). Cross-sectional imaging of the abdomen and
pelvis with CT or MRI is performed for surgical planning.
Functional imaging with 123 I-labeled metaiodobenzylguanidine
(MIBG) is a highly speciic test that can conirm the catecholaminesecreting
nature of a tumor, localize tumors not seen with
cross-sectional imaging, and identify other sites of disease. Because
MIBG testing is not 100% sensitive, additional nuclear medicine
imaging tests may need to be performed. Chest CT is performed
in patients with suspected lung metastases. 238
Adrenocortical Neoplasm
Primary tumors of the adrenal cortex are rare in children, with
an incidence of 0.3 to 0.4 cases per million per year before the
age of 15 years. 239 Because reliable histologic diferentiation
between cortical adenomas and carcinomas in children may be
diicult, the inclusive term “adrenocortical neoplasm” is oten
used. 240 Most tumors develop before 5 years of age, with a female
predominance, although the sex ratio is equal in adolescence.
In contrast to adults, most pediatric adrenocortical neoplasms
are hormonally active. he presence of increased hormone levels
is useful both for initial diagnosis and in the detection of tumor
recurrence. Androgen overproduction leads to virilization in
girls and precocious puberty in boys; most tumors also cause
an overproduction of mineralocorticoids. 238 Although the majority
of afected children will not have an underlying disorder, there
is a known association with Beckwith-Wiedemann syndrome
and Li-Fraumeni syndrome. 238
Tumors larger than 5 to 10 cm in diameter; a tumor weight
greater than 200 g; and aggressive growth features such as invasion
into the periadrenal sot tissues, kidneys, and/or inferior
vena cava (IVC) suggest malignancy. Small lesions tend to
be homogeneous, whereas larger lesions oten contain foci of
hemorrhage, necrosis, or calciication. 241 Adrenal carcinoma in
an 8-month-old girl with virilization and precocious puberty is
typical of these rare lesions (Fig. 52.76). Metastases occur most
oten to the liver, lung, and bone. 238 Sonography is particularly
helpful in the detection of tumor invasion into the IVC. Crosssectional
imaging with CT and MRI is used for more precise
delineation.