Kidney tumor
Adult renal cell carcinoma - rare
Hybrid oncocytic chromophobe tumor

Topic Completed: 1 September 2015

Minor changes: 15 March 2021

Copyright: 2002-2021,, Inc.

PubMed Search: Hybrid oncocytic chromophobe tumor

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Cite this page: Guilmette J, Albadine R. Hybrid oncocytic chromophobe tumor. website. Accessed April 15th, 2021.
Definition / general
  • Hybrid oncocytic / chromophobe tumor (HOCT) is a rare renal neoplasm classified as a subcategory of chromophobe renal cell carcinoma (Am J Surg Pathol 2013;37:1469)
  • Displays histological features of both renal oncocytoma (RO) and chromophobe renal cell carcinoma (ChRCC) including areas composed of "hybrid" cells with overlapping cytonuclear or histochemical features (Virchows Arch 2013;462:633)
  • Occurs (or arises) in three clinical settings: a sporadic tumor, associated with renal oncocytomatosis, and as a component of Birt-Hogg-Dubé syndrome (Histol Histopathol 2013;28:1257)
  • Typically occurs in adult males with an age range of 41 - 68 years (mean of 56) (BJU Int 2009;103:1381)
Clinical features
  • No specific clinical symptoms reported in patients with sporadic or associated with renal oncocytosis (Histol Histopathol 2013;28:1257)
  • Patients with Birt-Hogg-Dubé syndrome usually have characteristic clinical features: skin tumors such as fibrofolliculoma or trichodiscoma, pulmonary lesions including bullae and spontaneous pneumothorax (Histol Histopathol 2012;27:1407)
Radiology description
Prognostic factors
Case reports
Gross description
Microscopic (histologic) description
  • Noninfiltrative, well circumscribed intrarenal tumor
  • Solid alveolar and cystic architecture
  • Dual population of eosinophilic cells: oncocytic and chromophobe
  • Oncocytic cell: medium sized round cell with granular eosinophilic cytoplasm and concentric round nucleus with prominent nucleolus (Virchows Arch 2010;456:355)
  • Chromophobe cell: large, polygonal "plant-like" cell with a distinct cell membrane, containing flaky eosinophilic cytoplasm often with a perinuclear halo and an irregular "raisinoid" wrinkled nucleus
  • Third cell type may be seen with cytonuclear features overlapping both oncocytic and chromophobe morphology (Virchows Arch 2013;462:633)
  • May have vascular invasion (Pathol Res Pract 2005;201:385)
  • Mitotic rate is very low
  • Rarely have necrosis (Pol J Pathol 2014;65:93)
Microscopic (histologic) images

Contributed by Chin-Lee Wu, Ph.D., Harvard School of Medicine

Dual population of eosinophilic cells

Contributed by Roula Albadine, M.D. and Julie Guilmette, M.D.

Flaky eosinophilic cytoplasm

Oncocytic cells with granular eosinophilic cytoplasm, concentric round nucleus and prominent nucleoli

Hale colloidal iron

Cytology description
Positive stains
Molecular / cytogenetics description
  • May be associated with BHD, autosomal dominant syndrome characterized by a genetic abnormality on chromosome 17p11.2 leading to a mutation in the FLCN gene (Pol J Pathol 2014;65:93)
  • Sporadic forms may present with numerous molecular anomalies (both mono- and polysomies) of chromosomes 1, 2, 6, 9, 10, 13, 17, 21, and 22 and lack of mutations in the VHL, c-kit, PDGFRA, and FLCN genes (Virchows Arch 2010;456:355)
Electron microscopy description
  • Numerous mitochondria
  • Sparse microvesicles with amorphic lamellar content
  • Infrequently, small intracytoplasmatic tubuli covered by microvilli may be observed (Virchows Arch 2010;456:355)
Differential diagnosis
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