Abnormal nuclear structures (micronuclei, nuclear blebs, strings, and pockets) in a case of anaplastic giant cell carcinoma of the thyroid: an immunohistochemical and ultrastructural study.

The authors report a case of a 70-year-old woman with an anaplastic giant cell thyroid carcinoma, along with immunohistochemical and electron microscopic findings. Histologically, the tumor is characterized by mononucleated and multinucleated giant cells, lack of architectural cohesion, atypical mitoses, and extensive areas of coagulative necrosis. Tumor cells showed AE1/AE3 positivity as well as nuclear overexpression of p53 and ki-67. Semithin sections revealed multiple nuclei with heterogeneous size ranging from micronuclei to large-size (giant) nuclei. Micronuclei were confirmed by electron microscopy that disclosed also the presence of nuclear blebs, strings, and pockets. Morphological findings of these abnormal nuclear structures in conjunction with p53 and Ki-67 nuclear overexpression suggested a faulty mitotic checkpoint/mitotic catastrophe in the progression of anaplastic giant cell thyroid carcinoma.

Abnormal nuclear structures (micronuclei, nucleoplasmic bridges, and nuclear buds) in a pleomorphic giant cell carcinoma of the stomach.

A rare case of pleomorphic giant cell carcinoma of the stomach in a 70-year-old man is reported. Characteristic microscopic findings included a general lack of architectural cohesiveness, aggregates of mononucleated or multinucleated giant cells, extensive areas of coagulative necrosis, and numerous mitoses. Immunohistochemically, tumor cells displayed cytoplasmic immunoreactivity for cytokeratin AE1/AE3 as well as overexpression of p53 and Ki-67. Electron microscopy revealed paranuclear tonofilaments bundles in giant cells confirming their epithelial nature. Furthermore, giant cells contained two or more nuclei with heterogeneous size, nucleoplasmic bridges, nuclear buds, and micronuclei. Similar abnormal nuclear structures have been closely related to breakage-fusion-bridge type of mitotic disturbances in tumor cell lines, and have not been previously reported in a human tumor.

Supratentorial giant cell ependymoma.

Ependymomas account for 3 to 9% of all neuroepithelial tumors and, although occurring most often within the ventricular system, they may arise from the extraventricular parenchyma as well. Several histologic patterns of these neoplasm are well known, but little attention has been devoted to a variant composed of giant elements. We describe the case of a 13-year-old girl experiencing a 3-month history of partial seizures in whom cranial magnetic resonance imaging showed an extraventricular, right parietotemporal neoplasm, adherent to the overlying dura mater. Histologic, immunohistochemical and ultrastructural findings were consistent with those of a high-grade ependymoma. The tumor was characterized by the presence of a major component of pleomorphic giant cells, as also seen in pleomorphic xantoastrocytoma, subependymal giant cell astrocytoma and glioblastoma multiforme. Similar elements have been described in two filum terminale and one supratentorial, intraventricular ependymoma, respectively. Histologic and evolutional data of those and of our own case suggest that isolated giant cells are not necessarily linked to a bad prognosis in ependymomas.

[Giant acinic cell parotid gland adenocarcinoma of the papillary- cystic type]. / Adenocarcinoma gigante de células acinares de tipo quístico papilar en parótida.

A case of a 38-year-old male having an acinic cell adenocarcinoma of the parotid gland is reported. The tumor measured 22 cm and histologically it was of the papillary-cystic type. The following features were of interest: 1) the tumor size surpassed the size of previous reported acinic cell adenocarcinomas by 9 cm; and 2) the rarity of its histological variety (cystic papillary) demanded immunohistochemical and electron microscopic studies to confirm the diagnosis.

Adenocarcinoma gigante de células acinares de tipo quístico papilar en parótida / Giant acinic cell adenocarcinoma with papillary-cystic pattern of the parotid gland

Se presenta el caso de un hombre de 38 años de edad con un adenocarcinoma de células acinares de 22 cm de tipo quístico papilar, originado en la glándula parótida. El interés del caso radica en: 1) el tamaño del tumor que supera en 9 cm al adenocarcinoma de células acinares más grande hasta ahora informado; y 2) la rara variedad histológica quística y papilar demandó estudios de histoquímica, inmunohistoquímica y microscopía electrónica para su diagnóstico

Supratentorial giant cell ependymoma: a case report.

Ependymomas are neoplasms of the central nervous system that are capable of demonstrating remarkably heterogeneous histologic features. These tumors originate from ependymal cells lining the ventricles, the choroid plexus, the central canal of the spinal cord, and the filum terminale, so they are therefore seen throughout the neuraxis. We describe the case of a 26-year-old man who experienced a 3-week history of right-sided numbness and a 1-week history of worsening bifrontal headache. Computed tomographic scanning and magnetic resonance imaging of his head demonstrated an irregularly enhancing mass involving the left medial frontal lobe, with extension across the corpus callosum and expansion into the body and atrium of the left lateral ventricle. Histologic, immunohistochemical, and electron microscopic findings were consistent with an anaplastic ependymoma. Unique to this neoplasm was the presence of multiple tumor giant cells. The presence of pleomorphic tumor giant cells is a characteristic feature of the subependymal giant cell astrocytoma, and it is also commonly seen in pleomorphic xanthoastrocytoma and glioblastoma multiforme. Bizarre giant cells were recently described in two filum terminale ependymomas. This report presents the first case of a supratentorial giant cell ependymoma with anaplastic features.

Microwave-enhanced immunohistochemical staining of a formalin-sensitive antigen-laminin receptor.

Many potentially useful antigens have been difficult to detect in formalin-fixed, paraffin-embedded tissues. Recently a number of pathological and research laboratories have demonstrated that some antigens masked by formalin fixation could be restored to detectability by microwave heating. Previously, we were unable to demonstrate laminin receptor in cells processed by the routine fixation. Our results showed that microwave heating together with trypsin produced the best immunohistochemical staining for this receptor. Nevertheless, no significance was found in the levels of 67 kD LR in high and low metastatic tumor cell lines.