title: Cystic phaeochromocytoma is a distinctive subgroup with special clinical, imaging and histological features that might mislead the diagnosis.
abstract: OBJECTIVE
  To report and analyse cases of cystic phaeochromocytoma at our institution and in previous publications, as adrenal cystic masses are usually associated with nonfunctional lesions, but they can be phaeochromocytoma.
  
  
  METHODS
  The prospective adrenalectomy database at our institution was reviewed to identify patients with phaeochromocytoma and cystic lesions. The clinical, radiological and histological features of cystic phaeochromocytoma were evaluated. Other previously published data were identified and compared with the present series.
  
  
  RESULTS
  In all, there were 107 adrenalectomies at our institution from November 2000 to March 2007; 31 of these patients had a confirmed diagnosis of phaeochromocytoma and six (19%) were cystic phaeochromocytomas. Three of the six cases were asymptomatic and had a negative biochemical evaluation (one male and five females, mean tumour size 6.6 cm); the imaging diagnosis was mainly based on computed tomography and magnetic resonance imaging, and the foremost feature was the enhancement of the tumour rim associated with a central cystic mass. Nine other previously published cases were reviewed.
  
  
  CONCLUSIONS
  From the present large series and previous anecdotally reported cases, patients with cystic phaeochromocytomas are more likely to be asymptomatic, to complain of chronic abdominal pain, and to have a negative biochemical evaluation, which might deter physicians from conducting a full evaluation for phaeochromocytoma and mislead the final diagnosis. As such, there could be an even higher prevalence of this entity that is yet to be determined.
authors: Division of Urology, Federal University of Sao Paulo, Brazil. cassio.andreoni@globo.com
authors: Cassio
authors: C
authors: Andreoni
authors: Rodrigo K
authors: RK
authors: Krebs
authors: Paulo C
authors: PC
authors: Bruna
authors: Suzan M
authors: SM
authors: Goldman
authors: Claudio E
authors: CE
authors: Kater
authors: Maria T S
authors: MT
authors: Alves
authors: Valdemar
authors: V
authors: Ortiz
mesh_terms: D000293:Adolescent; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000601:surgery; D000315:Adrenalectomy; D000328:Adult; D000368:Aged; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D010535:Laparoscopy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010181:Pancreatic Cyst / Q000175:diagnosis* / Q000601:surgery; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000601:surgery; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed