Choroid plexus carcinoma: Report of a case with lmmunohistochemical and ultrastructural observations

Abstract

A choroid plexus carcinoma from the lateral ventricle of a ten‐month‐old boy was examined by light and electron microscopy. The neoplasm exhibited papillary and solid areas, invasion of adjacent brain, cytologic anaplasia, and necrosis. Intra‐ and extracellular PAS positive droplets were present, but no pigment was observed. No glial fibrillary acidic protein was detected within neoplastic cells. Ultrastructural examination revealed irregular nuclei with large nucleoli and occasional intranuclear filamentous rods. Cytoplasmic organelles included a moderate number of free ribosomes, rough endoplasmic reticulum, Golgi complexes, and microtubules. In some areas, numerous mitochondria filled the cytoplasm. Surface specializations included zonulae adherentes, microvilli, and clusters of cilia with a 9 + 0 microtubular pattern. Clusters of basal bodies with prominent basal feet and striated rootlets were present within the cytoplasm. Normal choroid plexus from this patient also had 9 + 0 cilia. In contrast, choroid plexus papillomas from two other infants had cilia with a 9 + 2 pattern. These observations demonstrate that both differentiated and anaplastic choroid plexus neoplasms have the potential to form cilia, and that the microtubular structure of such cilia may deviate from the usual 9 + 2 pattern.

Squash–prep cytology in the diagnosis of canine and feline nervous system lesions: a study of 42 cases

“…The final histologic diagnosis of carcinoma was based on the presence of single-cell infiltration into the fibrovascular cores, confirming that a definitive diagnosis of choroid plexus carcinoma could be made only after thorough histologic examination of the resected specimen. 35,37 Mesenchymal tumors were the neoplasms diagnosed most frequently in our series, accounting for 71% of total cases. In a previous paper, 7 where only primary brain tumors were included, mesenchymal tumors represented 57% of the total cases.…”

“…4 For these reasons, histologic diagnosis is often required to subsequently confirm cytologic information, and immunohistochemistry has become an indispensable technique for the confirmation, differentiation, classification, and final diagnosis of NS lesions and tumors. 35 Cytologic features suggesting a neuroepithelial origin include the following 36 : 1) soft texture of the specimens, which typically produces highly cellular smears; 2) fine fibrillary background; 3) perivascular arrangement with processes approaching the vascular lumen; 4) round nuclei with finely stippled chromatin; and 5) endothelial proliferation. Cytologic features of nonneuroectodermal lesions can vary considerably because of the extremely heterogeneous morphologic features of the above-mentioned 4 groups.…”

Choroid plexus and the blood–cerebrospinal fluid barrier in disease

“…CP tumors vary from papilloma with cytological and architectural reproduction of normal CP to anaplastic and invasive neoplasms terminating in lesions lacking any morphological evidence of CP origin [274].…”

Carcinoma of the choroid plexus: A pediatric experience

“…Several authors have retrospectively applied these criteria to published cases and have subsequently rejected some of them on the basis of incorrect classification [4,11,32,34].…”