Renal oncocytoma

Renal oncocytoma
Renal oncocytoma
	Micrograph of a renal oncocytoma.

A renal oncocytoma is a tumour of the kidney made up of oncocytes, epithelial cells with an excess amount of mitochondria.^[1]^[2]

Signs and symptoms

Renal oncocytomas are often asymptomatic and are frequently discovered by chance on a CT or ultrasound of the abdomen. Possible signs and symptoms of a renal oncocytoma include blood in the urine, flank pain, and an abdominal mass.

Pathophysiology

Renal oncocytoma is thought to arise from the intercalated cells of collecting ducts of the kidney. It represent 5% to 15% of surgically resected renal neoplasms. Ultrastructurally, the eosinophilic cells have numerous mitochondria.

Histologic appearance

An oncocytoma is an epithelial tumor composed of oncocytes, large eosinophilic cells having small, round, benign-appearing nuclei with large nucleoli and excessive amounts of mitochondria.

Diagnosis

In gross appearance, the tumors are tan or mahogany brown, well circumscribed and contain a central scar. They may achieve a large size (up to 12 cm in diameter).

The main differential diagnosis of renal oncocytoma is chromophobe renal cell carcinoma oncocytic variant, which like the renal oncocytoma has eosinophilic cytoplasm, but has perinuclear clearing and, typically, some degree of nuclear atypia.

Immunohistochemical profile

Cytokeratin AE1/AE3 +
Vimentin -
EMA +
CD10+/-
CK7 +/- parcellaire
CK20 -
CK19 -
AMACR (Racemase) -
S100 +
c-kit (CD117) +
Cadherin-E +
TFE3 -
CAM5.2 +

^[3]

Treatment

Renal oncocytoma is considered benign, cured by nephrectomy. There are some familial cases in which these tumors are multicentric rather than solitary.^[4] However, they may be resected to exclude a malignant tumor, e.g. renal cell carcinoma.

Prognosis

The overall five-year survival rate has been estimate to be 63%, with most individuals dying from cardiovascular diseases or other cancers.^[5]

Additional images

Micrograph of a renal oncocytoma. H&E stain.
Micrograph of a renal oncocytoma. H&E stain.
Micrograph of a renal oncocytoma. H&E stain.
Micrograph of a renal oncocytoma. H&E stain.
Micrograph of a renal oncocytoma. H&E stain.
Micrograph of chromophobe RCC oncocytic variant, the main differential diagnosis of renal oncocytoma.

References

^ Coburn V, Radfar A, Snook D, Mahalingam M (2007). "Cutaneous oncocytoma - a report of three cases and review of the literature". J. Cutan. Pathol. 34 (4): 355–9. doi:10.1111/j.1600-0560.2006.00620.x. PMID 17381809.
^ "Atlas of Genetics and Cytogenetics in Oncology and Haematology - Thyroid:oncocytic tumors". Retrieved 2009-02-01.
^ [Renal Neoplasms: An Update on Immunohistochemical and Histochemical Features http://www.dako.com/08066_12may10_webchapter26.pdf]
^ Robbins pathology, page 1015^{[full citation needed]}
^ Gudbjartsson, Tomas; Hardarson, Sverrir; Petursdottir, Vigdis; Thoroddsen, Asgeir; Magnusson, Jonas; Einarsson, Gudmundur V. (2005). "Renal oncocytoma: a clinicopathological analysis of 45 consecutive cases". BJU International. 96 (9): 1275–1279. doi:10.1111/j.1464-410X.2005.05827.x. ISSN 1464-4096.

External links

[pmid17381809-1] Coburn V, Radfar A, Snook D, Mahalingam M (2007). "Cutaneous oncocytoma - a report of three cases and review of the literature". J. Cutan. Pathol. 34 (4): 355–9. doi:10.1111/j.1600-0560.2006.00620.x. PMID 17381809.

[2] "Atlas of Genetics and Cytogenetics in Oncology and Haematology - Thyroid:oncocytic tumors". Retrieved 2009-02-01.

[3] [Renal Neoplasms: An Update on Immunohistochemical and Histochemical Features http://www.dako.com/08066_12may10_webchapter26.pdf]

[4] Robbins pathology, page 1015^{[full citation needed]}

[GudbjartssonHardarson2005-5] Gudbjartsson, Tomas; Hardarson, Sverrir; Petursdottir, Vigdis; Thoroddsen, Asgeir; Magnusson, Jonas; Einarsson, Gudmundur V. (2005). "Renal oncocytoma: a clinicopathological analysis of 45 consecutive cases". BJU International. 96 (9): 1275–1279. doi:10.1111/j.1464-410X.2005.05827.x. ISSN 1464-4096.

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