Multimodality imaging findings of pheochromocytoma with associated clinical and biochemical features in 53 patients with histologically confirmed tumors.
OBJECTIVE
The purpose of this study was to determine the spectrum of imaging appearances of pheochromocytoma and the associated clinical and biochemical features.


METHODS
In this retrospective study, a citywide pathology database (2000-2011) was searched to identify the records of patients with pheochromocytoma. The search yielded the cases of 53 patients (28 men, 25 women; mean age, 50 years). The institutional PACS and radiology information system records, hospital charts, and the provincial electronic health records of these patients were reviewed. Imaging appearances and clinical and biochemical features related to pheochromocytomas were recorded.


RESULTS
One chart was not available for review. In the 52 cases analyzed, 40 of the patients had symptoms: 31 patients had hypertension; 10 had the triad of palpitations, diaphoresis, and headaches; and all had elevated urinary metanephrine concentrations. Seven patients had a familial syndrome, and five had bilateral pheochromocytomas. One patient had an extraadrenal pheochromocytoma, and five had malignant tumors. The mean size of pheochromocytomas was 4.0 cm. Most pheochromocytomas were heterogeneous (CT, 56%; MRI, 65%; ultrasound, 45%) and were MIBG positive (90%). Eleven of 34 (32%) pheochromocytomas had T2 signal intensity greater than that of the spleen. Most pheochromocytomas were less enhancing than the spleen (CT, 85%; MRI, 71%). Contrast-enhanced CT was performed on 33 tumors, of which 20 enhanced less than the spleen and 8 showed similar enhancement to the spleen; contrast-enhanced MRI was performed on 24 tumors, of which 12 enhanced less than the spleen and 5 showed similar enhancement to the spleen. Predominant cystic change was found in 4 of 20 (20%) ultrasound, 9 of 41 (22%) CT, and 11 of 34 (32%) MRI examinations. Eight of 34 (24%) pheochromocytomas were hemorrhagic, two (5%) had calcifications, and three of six were PET positive. Two cystic pheochromocytomas and one lipid-containing pheochromocytoma were misdiagnosed as adrenal adenomas.


CONCLUSIONS
Most pheochromocytomas were heterogeneous at imaging, were MIBG positive, accompanied elevated urinary metanephrine concentrations, and were symptomatic. High T2 signal intensity was found in approximately one third of solid tumors. Atypical imaging features included homogeneity, cystic change, hemorrhage, intense enhancement, calcifications, intracellular lipid, bilaterality, and malignancy.
1 Department of Radiology and Diagnostic Imaging, University of Alberta, Walter C. Mackenzie Health Sciences Centre, 2A2.41, 8440 112 St NW, Edmonton, AB T6G 2B7 Canada.
Asim
A
Raja
Katherine
K
Leung
Michael
M
Stamm
Safwat
S
Girgis
Gavin
G
Low
D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000097:blood* / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010673:Pheochromocytoma / Q000097:blood* / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013382:Subtraction Technique; D055815:Young Adult
D015415:Biomarkers