Metastatic Renal Cell Carcinoma to the Brain: A Contemporary Clinicopathologic Analysis With Comparison of Immunohistochemical Profiles to Selected Primary Brain Tumors With Clear Cell Features

Abstract

Brain metastases from renal cell carcinoma (RCC) are associated with significant morbidity and mortality. However, there are only few large series in the pathology literature specifically analyzing the clinicopathologic and immunohistochemical features in comparison with primary brain tumors with clear cell features. We identified 34 cases of metastatic RCC to the brain from the Urologic Pathology and Neuropathology files of 2 institutions between 2000 and 2018. Mean patient age at diagnosis of primary RCC was 59 years (range: 37 to 82 y). The mean size of 34 primary RCC was 7.9 cm (range: 2.5 to 19.5 cm). Twenty of 34 (59%) cases of brain metastases had primary RCC categorized as pT3. Brain imaging showed a solitary, well circumscribed, enhancing lesion in 18 of 34 (53%) patients and multifocal lesions in 16 of 34 (47%) patients. The mean size of metastatic RCC to the brain was 2.3 cm (range: 0.3 to 5.5 cm). Fifteen of 34 (44%) cases had isolated brain metastases and 19 of 34 (56%) cases had concomitant extracerebral metastases. The histologic subtypes were clear cell RCC 29 of 34 (85%) cases, RCC unclassified 4 of 34 (12%) cases, and papillary RCC 1 of 34 (3%) cases. We also included primary brain tumors with clear cell features including hemangioblastoma (30 cases), microcystic meningioma (11 cases), and clear cell meningioma (3 cases). The utility of an immunohistochemical panel that includes PAX8, carbonic anhydrase IX, SST2Ra, and inhibin is very useful in the distinction of these entities in a subset of patients.

Intracytoplasmic dot‐like inclusions as cytopathologically useful findings of ependymoma: Case report of adolescent supratentorial anaplastic ependymoma with clear cell morphology

“…3,8,9 Therefore, when diagnosing supratentorial clear cell neoplasms, we have to consider the following differential diagnoses: CC-EPN, The major points of the differential diagnoses of CC-EPN, OD, CN, and ccRCC are summarized in Table 1. 1,[10][11][12][13][14][15][16][17][18][19][20] First, clinically, CC-EPNs affect young patients whereas the other tumors tend to occur in middle-aged patients. 1,11,12 The foramen of Monro is the area most frequently affected by CNs, which differs from CC-EPNs, OD, or metastatic ccRCC.…”

Meningioma: A Pathology Perspective

“…Although the two share protein expression of EMA, immunohistochemical staining for PAX8, CD10, and carbonic anhydrase IX typically shows expression in clear cell carcinoma, whereas meningiomas are expected to be negative. 64,65 Chordoid meningioma shares many characteristics with chordomas. Though most chordomas occur in the sacrum, intracranial (eg, clival) tumors are not uncommon.…”