Papillomas and carcinomas of the choroid plexus: histological and immunohistochemical studies and comparison with normal fetal choroid plexus

Abstract

-Background: Choroid plexus tumors are rare. Results on immunohistochemical features are scanty and controversial even regarding normal plexus. Method: Thirteen cases of choroid plexus tumors and five samples of normal fetal choroid plexus were submitted to immunohistochemical study using a panel of epithelial, neuronal and stromal markers. Results/Conclusions: Relevant histological findings were presence of clear cells in 3/5 papillomas (PP) and 7/8 carcinomas (CA) and all 5 fetal plexuses; rhabdoid cells, desmoplasia and vascular proliferation were found respectively in 3, 4 and 5 cases out of 6 poorly differentiated CA and were absent in PP and well differentiated CA. Pancytokeratin AE1/AE3 was strongly positive in all 13 cases, even in the undifferentiated component of poorly differentiated CA, where reactivity was focal in 3 and diffuse in 3 cases. Low molecular weight cytokeratin (35βH11) was not expressed in any of the 8 CA, but was present in all 5 PP. In 4 of 6 poorly differentiated CA there was reactivity for smooth muscle actin (1A4) in 10 to 30% of the cells. This was true also for one case lacking rhabdoid cells. Laminin was undetectable in all 6 cases of poorly differentiated CA but was present in 4 PP and 2 well differentiated CA. All 5 fetal plexuses expressed GFAP.KEY WORDS: choroid plexus tumors, normal fetal choroid plexus, immunohistochemistry, central nervous system. Papilomas e carcinomas do plexo coróide: estudo histológico e imuno-histoquímico e comparação com plexo coróide fetal normal RESUMO -Contexto: Os tumores do plexo coróide são raros. Os resultados de dados imuno-histoquímicos são escassos e controversos, o mesmo valendo para o plexo coróide normal. Método: Treze casos de tumores do plexo coróide e cinco exemplares de plexo coróide fetal normal foram submetidos a estudo imuno-histoquímico, utilizando-se marcadores para antígenos epiteliais, neurais e estromais. Resultados/Conclusão: Os achados histológicos mais relevantes foram células claras em 3/5 papilomas (PP) e 7/8 carcinomas (CA) e em todos os 5 plexos fetais; células rabdóides, desmoplasia e proliferação vascular foram encontradas, respectivamente, em 3, 4 e 5 casos de 6 CA pouco diferenciados, mas não nos PP e CA bem diferenciados. A pancitoqueratina AE1/AE3 foi fortemente positiva em todos os 13 casos, mesmo no componente indiferenciado do CA pouco diferenciado, em que a reatividade foi focal em 3 casos e difusa em outros 3. A citoqueratina de baixo peso molecular (35βH11) não foi expressa em nenhum dos 8 CA, mas estava presente em todos os 5 PP. Em 4/6 CA pouco diferenciados houve reatividade para actina de músculo liso (1A4) em 10-30% das células. Este achado ocorreu também em um caso sem células rabdóides. Laminina não foi detectada em nenhum dos 6 CA pouco diferenciados, mas estava presente em 4 PP e em 2 CA bem diferenciados. Todos os 5 plexos fetais expressaram GFAP. PALAVRAS-CHAVE: tumores do plexo coróide, plexo coróide fetal normal, imuno-histoquímica, sistema nervoso central.

Imaging findings of extraventricular choroid plexus papillomas: A study of 10 cases

“…The presence of necrosis has been considered as malignancy criteria (20,21). None of the cases in our series had notable necrosis, either on the MRI or under a microscope, which is consistent with the benign nature of CPPs.…”

Choroid plexus carcinoma with neuronal and glial differentiation in a 7-week-old male Sprague-Dawley rat

“…The tubular, cribriform or solid growth pattern of epithelial tumor cells might be observed as poorly defined papillary structures. Indeed, a solid growth pattern has previously been reported in undifferentiated choroid plexus carcinoma [1]. Furthermore, the tumor cells showed nuclear atypia, increased mitosis and invasion of the surrounding brain parenchyma; cyto-architecture of the malignancy strongly suggested that the present case was a choroid plexus carcinoma.…”

“…Interestingly, we identified atypical cells, elongated cells or intermediate pleomorphic cells, suggesting as the cyto-architecture features of malignancy. Atypical tumor cells, such as clear cells or rhabdoid cells, have been found in human choroid plexus carcinoma [1]; however, elongated cells and intermediate pleomorphic cells were not reported to our knowledge.…”

“…a) The immunohistochemical result of eight cases of humans studied in the report [1]. b) The immunohistochemical result of three cases of dogs studied in the report [9].…”

MGMT promoter methylation and temozolomide response in choroid plexus carcinoma

“…Immunohistochemically, cytokeratin and vimentin are frequently expressed in CPP and CPC whereas transthyretin, which is a specific marker for CPT, S-100 protein, and GFAP, is less frequently expressed in CPC than in CPP [5,18,19]. Immunodetection of CEA and EMA is variously reported in CPT [5,19,20]. The differential diagnosis of CPC includes metastatic adenocarcinomas and anaplastic ependymomas [4,21,22].…”