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RCOM
RADIOLOGICAL
CASE OF THE MONTH
Sam T. Auringer, MD; T. David Cox, MD; Thomas E. Sumner, MD
CASE SUMMARY
A 3-year-old girl presents with refusal to walk, weakness, leg cramps, and a 20-month history of chronic
diarrhea. Initial laboratory workup revealed a significant hypokalemia. Subsequent diagnostic imaging studies
appear in figures 1, 2, and 3.
A
B
FIGURE 1. An anteroposterior supine conventional
radiograph reveals a left-sided posterior mediastinal
mass and dilated loops of both large and small bowel.
FIGURE 2. These axial CT images (A) before and (B) after IV
contrast administration reveal a partially calcified left paraspinal
posterior mediastinal mass without gross intraspinal extension.
March 2000
APPLIED RADIOLOGY ■ 47

FIGURE 3. An axial CT image of the pelvis demonstrates
multiple fluid-filled bowel loops.
DIAGNOSIS
Thoracic ganglioneuroma presenting with the
watery diarrhea, hypokalemia, and achlorhydria
(WDHA) syndrome.
IMAGING FINDINGS
Findings indicative of a posterior mediastinal
mass on plain film and chest computed tomography
(CT) scans suggest the diagnosis of a neurogenic
tumor, as 95% of pediatric posterior mediastinal
masses are of neurogenic origin. The primary
differential considerations are tumors of sympathetic
ganglion origin (i.e., neuroblastoma, ganglioneuroblastoma,
and ganglioneuroma). 1 The patient’s age
favored a neuroblastoma or ganglioneuroblastoma, as
ganglioneuroma tends to occur in older children.
Plain film findings of thoracic neuroblastoma include
a posterior mediastinal mass, possibly associated
with ribs that are splayed or eroded or both;
calcifications; and enlarged intervertebral foramina in
cases with intraspinal extension of tumor. CT
demonstrates calcification in approximately 90% of
neuroblastomas. Magnetic resonance (MR) imaging
is the test of choice for thorough evaluation of
intraspinal extension of tumor. 2
DISCUSSION
The WDHA syndrome is an unusual paraneoplastic
condition caused by excess vasoactive intestinal
peptide (VIP) secretion by certain tumors,
including the neuroblastoma-ganglioneuroblastomaganglioneuroma
spectrum in children and non-beta
pancreatic islet cell tumors, squamous cell tumors
of the lung or esophagus, cutaneous mast cell tumors,
and pheochromocytomas in adults. 3 Ganglioneuromatosis
of the small intestine and pancreas,
causing hypersecretion of VIP, has been reported. 4
The WDHA syndrome has also been referred to as
the vipoma syndrome, pancreatic cholera, the
watery diarrhea syndrome, and the Verner-Morrison
syndrome after its discoverers in 1958. 5 Clinically, the
onset of WDHA syndrome is typically insidious and
diagnosis is often delayed for months or even years.
The clinical hallmark is an unremitting secretory
diarrhea that persists despite fasting. Diagnosis
requires documentation of elevated serum VIP levels
with subsequent localization of the VIP-secreting
tumor. Surgical resection is usually curative, as it was
in this case.
REFERENCES
1. Hedlund GL, Griscom NT, Cleveland RH, Kirks DR: Respiratory system. In: Kirks DR (ed): Practical Pediatric Imaging: Diagnostic Radiology
of Infants and Children, ed 3, pp 790-792. Philadelphia, Lippincott-Raven, 1998.
2. Abramson SJ: Adrenal neoplasms in children. Radiol Clin North Am 35:1415-1453, 1997.
3. Grier JF: WDHA (watery diarrhea, hypokalemia, achlorhydria) syndrome: Clinical features, diagnosis, and treatment. South Med J 88:22-24,
1995.
4. Shulman DI, McClenathan DT, Harmel RP, et al: Ganglioneuromatosis involving the small intestine and pancreas of a child and causing
hypersecretion of vasoactive intestinal polypeptide. J Pediatr Gastroenterol Nutri 22:212-218, 1996.
5. Castleberry RP: Biology and treatment of neuroblastoma. Pediatr Clin North Am 44:919936, 1997.
Prepared by Sam T. Auringer, MD; T. David Cox, MD; and Thomas E. Sumner, MD, Department of Radiology,
Wake Forest University Baptist Medical Center, Winston-Salem, NC.
48 ■ APPLIED RADIOLOGY March 2000