title: Adrenocortical oncocytoma presenting as Cushing's syndrome: an additional report of a paediatric case.
abstract: Oncocytomas are tumours predominantly or exclusively composed of oncocytes, cells with granular and eosinophilic cytoplasm filled with mitochondria. Although they can occur in every organ, they are rare in adrenal glands, and in paediatric patients they are even rarer, with only three case reports previously published. We present a preschool child developing Cushing's syndrome due to an adrenocortical oncocytoma, which was confirmed immunohistochemically with antibodies to the mitochondrial electron complex 2. A 5.8-year-old girl presented with clinical features of Cushing's syndrome. ACTH-independent hypercortisolism was confirmed biochemically and a left adrenal mass was detected by imaging and removed by laparotomy. Histopathological analysis revealed a tumour composed of more than 95 % of oncocytes, confirmed immunohistochemically with antibodies to subunits A and B of the mitochondrial enzyme succinate dehydrogenase. Using the Lin-Weiss-Bisceglia score system and the reticulin algorithm, this tumour was categorized as a benign adrenocortical oncocytoma. The patient currently has 64 months of follow-up, without any evidence of relapse of symptoms. To our knowledge, we herein present the youngest patient developing an adrenocortical oncocytoma and the first manifestation of Cushing's syndrome due to this rare neoplasm in paediatric patients. We also emphasize the clinical usefulness of immunohistochemistry to the mitochondrial enzyme succinate dehydrogenase to confirm the oxyphilic nature of adrenocortical oncocytomas.
authors: Serviço de Endocrinologia e Diabetes, Hospital Garcia de Orta, E.P.E., Avenida Torrado da Silva, 2801-951, Almada-Setúbal, Portugal, bern1981@gmail.com.
authors: Bernardo Dias
authors: BD
authors: Pereira
authors: Elisabete Silva
authors: ES
authors: Rios
authors: Rafael Adame
authors: RA
authors: Cabrera
authors: Jorge
authors: J
authors: Portugal
authors: Luísa
authors: L
authors: Raimundo
mesh_terms: D018249:Adenoma, Oxyphilic / Q000175:diagnosis* / Q000201:enzymology / Q000473:pathology / Q000601:surgery; D000306:Adrenal Cortex Neoplasms / Q000175:diagnosis* / Q000201:enzymology / Q000473:pathology / Q000601:surgery; D002648:Child; D003480:Cushing Syndrome / Q000175:diagnosis*; D003937:Diagnosis, Differential; D042963:Electron Transport Complex II / Q000032:analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D013385:Succinate Dehydrogenase / Q000032:analysis
chemical_list: D042963:Electron Transport Complex II; C511268:SDHA protein, human; C108095:SDHB protein, human; D013385:Succinate Dehydrogenase