glycogen and Peripheral-Nervous-System-Neoplasms

A primary malignant peripheral nerve sheath tumor (MPNST) of the pleura that clinically mimicked a malignant mesothelioma in a 57-year-old man is described. Histologically, the tumor had features similar to those described in cases of the so-called epithelioid MPNST. A unique finding in this case was the demonstration of keratin expression in the epithelioid component of the tumor, as well as the presence of rhabdomyoblasts. This is the first example of an MPNST with heterologous elements arising in the pleura. Immunohistochemical and ultrastructural studies were important in differentiating this tumor from other malignancies with sarcomatoid and epithelioid features involving the pleura.

Topics: Actin Cytoskeleton; Biomarkers, Tumor; Cell Differentiation; Diagnosis, Differential; Fatal Outcome; Glycogen; Humans; Keratins; Male; Mesothelioma; Middle Aged; Neoplasm Recurrence, Local; Nerve Sheath Neoplasms; Peripheral Nervous System Neoplasms; Pleural Neoplasms; Rhabdomyosarcoma

A postmortem study of 64 vagus nerves from 32 children up to 1 year of age was done to determine the incidence of ectopic parathyroid tissue. The segments of nerve (average length, 2.6 cm), including the entire ganglion nodosum, were examined using a combination of step and serial sectioning. Discrete solitary collections of ectopic parathyroid chief cells were seen in 6% of vagus nerves and ranged in diameter from 162 to 360 micron. Confirmation of the nature of the cells was based on the presence of abundant glycogen and positive immunoreactivity for chromogranin and parathormone. The possible significance of intravagal parathyroid tissue is briefly discussed.

Topics: Choristoma; Chromogranins; Glycogen; Humans; Immunohistochemistry; Infant; Parathyroid Glands; Parathyroid Hormone; Peripheral Nervous System Neoplasms; Vagus Nerve

Ewing's sarcoma (ES) of bone may occasionally display rosette-like textures mimicking Homer-Wright ones, as seen in neuroectodermic neoplasms (neuroblastoma, peripheral neuroepithelioma). Of a group of 39 cases of ES, reviewed with electron microscopic study, the authors have isolated five atypical ES, which histologically also possessed neuroectodermic traces. These tumors were composed of small round blue cells with rosette-like figures and cytoplasmic glycogen. The immunohistochemical analysis showed positivity for neuron-specific enolase (NSE) as well as for HNK-1 (leu-7) monoclonal antibody. Electron microscopic examination confirmed the tumor cell as being of small round type, with a dense chromatine pattern and the presence of isolated dendritic processes, as well as synaptic-like buttons; intermediate filaments, neurotubuli, and dense-core neurosecretory granules also were seen. Moreover, in two cases basement-like condensations surrounded some cells. Scanning electron microscopic study in one case confirmed the presence of rosette-like figures and cell elongations with short dendritic projections of the cytoplasm. Clinically and radiologically these cases showed features similar to ES of bone; one case, located in the chest wall, had a local relapse after treatment, with the histologic features of a pleomorphic neuroblastoma. The authors conclude that these tumors resemble closely immature neuroepithelioma of soft tissue but, being primary to bone, are superimposable on those described as "neuroectodermal tumors of bone."

Topics: Antibodies, Monoclonal; Antigens, Differentiation, T-Lymphocyte; Antigens, Surface; Bone Neoplasms; Glycogen; Histocytochemistry; Immunologic Techniques; Microscopy, Electron; Microscopy, Electron, Scanning; Neuroblastoma; Neuroectodermal Tumors, Primitive, Peripheral; Peripheral Nervous System Neoplasms; Phosphopyruvate Hydratase; Sarcoma, Ewing