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Renal neuroendocrine tumors.

Lane BR, Jour G, Zhou M - Indian J Urol (2009)

Bottom Line: In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis.Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease.A spectrum of NETs can rarely occur in the kidney.

View Article: PubMed Central - PubMed

Affiliation: Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio, USA.

ABSTRACT

Objectives: Neuroendocrine tumors (NETs) are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC), and large cell neuroendocrine carcinoma (LCNEC) are exceedingly rare.

Materials and methods: The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature.

Results: Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma) can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease.

Conclusions: A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

No MeSH data available.


Related in: MedlinePlus

Small cell carcinoma (a) has tumor cells with scant cytoplasm, finely granular chromatin with inconspicuous nucleoli, high mitotic rate and tumor necrosis. Large cell neuroendocrine carcinoma (b) has a solid growth pattern, large zone necrosis, large cell size, low nuclear to cytoplasmic ratio, vesicular chromatin, and frequent mitosis
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Figure 0002: Small cell carcinoma (a) has tumor cells with scant cytoplasm, finely granular chromatin with inconspicuous nucleoli, high mitotic rate and tumor necrosis. Large cell neuroendocrine carcinoma (b) has a solid growth pattern, large zone necrosis, large cell size, low nuclear to cytoplasmic ratio, vesicular chromatin, and frequent mitosis

Mentions: Renal carcinoid tumors typically present with a trabecular or ribbon-like growth pattern along with peripheral palisading. This leads to the typical rosette-like arrangement which is characteristic of these tumors [Figure 2]. Cells are polygonal with homogenous chromatin repartition and round to oval nuclei. Rare mitotic events are usually seen (<2 per high- power fields HPF). Necrosis is usually lacking.[19] However, the occasional pseudo-papillary appearance of carcinoid tumors may lead to misdiagnosis.[1519] In our study, one renal carcinoid was initially misdiagnosed as papillary tubular carcinoma and the diagnosis was changed to carcinoid tumor only after a metastatic carcinoid tumor was found in the liver.[7] Of the reported cases in the medical literature 14.5% were initially misdiagnosed histopathologically because of the rarity of such tumors and the lack of a fully blown neuroendocrine syndrome. Only after retrospective analysis, were these tumors characterized as carcinoid tumors. Necrosis, calcification and hemorrhage are often identified in carcinoid tumors. While necrosis and hemorrhage are associated with a more aggressive course and a poorer prognosis, calcification is considered a stigmata of long-term tumor growth and is associated with a more indolent course.[15] None of these differences were proven to be statistically significant.[15]


Renal neuroendocrine tumors.

Lane BR, Jour G, Zhou M - Indian J Urol (2009)

Small cell carcinoma (a) has tumor cells with scant cytoplasm, finely granular chromatin with inconspicuous nucleoli, high mitotic rate and tumor necrosis. Large cell neuroendocrine carcinoma (b) has a solid growth pattern, large zone necrosis, large cell size, low nuclear to cytoplasmic ratio, vesicular chromatin, and frequent mitosis
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2710056&req=5

Figure 0002: Small cell carcinoma (a) has tumor cells with scant cytoplasm, finely granular chromatin with inconspicuous nucleoli, high mitotic rate and tumor necrosis. Large cell neuroendocrine carcinoma (b) has a solid growth pattern, large zone necrosis, large cell size, low nuclear to cytoplasmic ratio, vesicular chromatin, and frequent mitosis
Mentions: Renal carcinoid tumors typically present with a trabecular or ribbon-like growth pattern along with peripheral palisading. This leads to the typical rosette-like arrangement which is characteristic of these tumors [Figure 2]. Cells are polygonal with homogenous chromatin repartition and round to oval nuclei. Rare mitotic events are usually seen (<2 per high- power fields HPF). Necrosis is usually lacking.[19] However, the occasional pseudo-papillary appearance of carcinoid tumors may lead to misdiagnosis.[1519] In our study, one renal carcinoid was initially misdiagnosed as papillary tubular carcinoma and the diagnosis was changed to carcinoid tumor only after a metastatic carcinoid tumor was found in the liver.[7] Of the reported cases in the medical literature 14.5% were initially misdiagnosed histopathologically because of the rarity of such tumors and the lack of a fully blown neuroendocrine syndrome. Only after retrospective analysis, were these tumors characterized as carcinoid tumors. Necrosis, calcification and hemorrhage are often identified in carcinoid tumors. While necrosis and hemorrhage are associated with a more aggressive course and a poorer prognosis, calcification is considered a stigmata of long-term tumor growth and is associated with a more indolent course.[15] None of these differences were proven to be statistically significant.[15]

Bottom Line: In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis.Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease.A spectrum of NETs can rarely occur in the kidney.

View Article: PubMed Central - PubMed

Affiliation: Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, Ohio, USA.

ABSTRACT

Objectives: Neuroendocrine tumors (NETs) are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC), and large cell neuroendocrine carcinoma (LCNEC) are exceedingly rare.

Materials and methods: The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature.

Results: Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma) can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease.

Conclusions: A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

No MeSH data available.


Related in: MedlinePlus