Gerald Fine

Comparative Ultrastructure of the Sinus Node in Man and Dog

Ultrastructure of the sinus node was studied in human and canine hearts and found to be similar. The principal cell of the sinus node is a small round pale cell with randomly distributed sarcosomes and sparse myofibrils. These cells have been designated as P cells. They occur in elongated clusters and make contact with each other in all directions but do not make direct contact with ordinary working myocardium. Transitional cells, which have features intermediate between P cells and working myocardium, serve as the connections between P cells and the rest of the heart. Each P cell is surrounded by a plasma membrane and groups of them are bound by a basement membrane. The only specialized junction between P cells is the desmosome, which occurs singly and seldom, with most contact being between apposing plasma membranes. P cells exhibit unusually active pinocytosis but have only a sparsely developed sarcoplasmic reticulum. The sarcosomes of P cells are much simpler in internal structure than are those of adjacent working myocardium obtained at the same time in the same heart in the same way, by direct perfusion with glutaraldehyde into the beating sinus node. Correlation of the electron microscopic appearance of the sinus node with that based on light microscopy is discussed, and some of the possible functional significances of the fine structure are considered.

Primary papillary serous neoplasia of the peritoneum: a clinicopathologic and ultrastructural study of eight cases.

The well-documented but rare primary papillary serous peritoneal tumors are difficult problems for the pathologist and the clinician. Because of their unusual location, these tumors are often classified as mesothelioma or advanced ovarian carcinoma. In this study, we report the clinicopathologic features of eight primary peritoneal serous papillary tumors and compare their histologic and ultrastructural features to 12 serous ovarian tumors and 16 epithelial mesotheliomas (two peritoneal and 14 pleural). The eight peritoneal serous papillary tumors occurred in women aged 19 to 75 years; two were serous tumors of low malignant potential (borderline) and six were serous carcinomas. The tumors were located in the mesosalpinx, left pelvis, omentum, and/or surface of the ovary. The two patients with borderline neoplasms had long disease-free survival (11 years and 20 years), while three of the four patients with carcinoma with more than 1 year of follow-up died of disease. The peritoneal serous papillary tumors were morphologically identical to serous ovarian tumors of equivalent grade. Well-differentiated papillary structures with distinct fibrovascular cores and one or several layers of columnar, crowded cells, dense overlapping nuclei with a long axis perpendicular to the surface of the papillary cores, and numerous psammoma bodies were features of the peritoneal and ovarian serous tumors. In contrast, the tubulo-alveolar, solid, or poorly defined papillary structures lined by well-spaced polygonal to cuboidal cells with abundant cytoplasm, absence of nuclear polarity, and infrequent psammoma bodies characterized the mesotheliomas. Epithelial mucin and carcinoembryonic antigen (CEA) immunoreactivity, when present, supported a diagnosis of serous tumor in these generally mucin-poor and CEA-negative neoplasms. Ultrastructurally, the cells of serous tumors had slender, straight microvilli of variable length interspersed with or without cilia, while the nonciliated cells of mesothelioma had long, exuberant, wavy microvilli. The morphologic and clinical features of the peritoneal papillary serous tumors are distinctive enough to warrant their separation from mesotheliomas.

PSEUDOANEURYSM OF THE HEART. REPORT OF A CASE AND REVIEW OF LITERATURE.

A case is reported of coronary atherosclerosis leading to myocardial infarction of the left ventricle and rupture of the left lateral posterior wall with limitation of the hemorrhage by fibrotic parietal pericardium. Formation of the false aneurysm allowed the patient to survive 5 years and 10 months after it was clinically recognized.

Central Nervous System Involvement in Whipple's Disease*

The pathologic changes in the brains of two cases of Whipples Disease have been described. The lesions are considered specific and, thus, constitute additional evidence of the systemic nature of the disease.

Cardiac Myxoma. A morphologic and histogenetic appraisal

A histologic study of 31 cardiac myxomas has shown a consistent cell type and growth pattern differing from that seen in thrombi and other cardiac neoplasms. Exaggerated proliferation of the myxoma cells and their polysaccharide production are believed to be the source of the epithelium‐like and gland‐like tissue as well as the polysaccharide rich stroma found in cardiac myxomas. Light‐microscopic, enzyme histo‐chemistry and electron‐microscopic studies support a neoplastic endocardial cell origin for the cardiac myxoma.

Cardiac myxoma (Endocardioma): An immunocytochemical assessment of histogenesis

Abstract Eighteen cardiac myoxomas having a variety of histologic patterns were stained for factor VIII related antigen utilizing the peroxidase-antiperoxidase technique. Regardless of their histologic appearance, intense reactivity for factor VIII related antigen was found in tumor cells, whereas four other intracardiac tumors did not stain. Since factor VIII related antigen is known to be elaborated only by endothelial cells and megakaryocytes, it is concluded that cardiac myxoma cells, which similarly synthesize this antigen, originate from endothelial or endocardial cells.

Ultrastructure of the esthesioneuroblastoma.

A tumor in the anatomic location and with the light microscopic appearance of an esthesioneuroblastoma was examined with the electron microscope. Secretory‐type granules, cytoplasmic fibrils, and microtubules similar to those described in neuroblastomas were found in many of the tumor cells, which supports an origin from the sympathetic autonomic nervous system. Similar organelles were found in three other nasal tumors considered to be esthesioneuroblastomas, but their detail was obscured because they were examined after being initially processed in paraffin.

Metaphyseal chondrodysplasia of Jansen.

1. A case is described for which the name metaphyscal chondrodysplasia of Jansen is suggested. 2. Biochemical changes were found simulating those caused by hyperparathyroidism, but different and distinctive roentgenographic findings were also evident. Parathyroid exploration was negative for hyperplasia or adenoma. 3. It is postulated that the metabolic changes—hypercalcaemia and hypophosphataemia—may have been secondary to the unverlying bone defect.

Congenital testicular juvenile granulosa cell tumor in a neonate with X/XY mosaicism

A congenital sex cord-stromal tumor of the testis with morphologic features of juvenile granulosa cell tumor is reported. The tumor occurred in an abdominal testis of a newborn infant with an X/XY karyotype and ambiguous genitalia and presented as a partially cystic mass associated with ascites. Histologically the tumor was comprised of an admixture of solid, cellular, poorly differentiated lobules mimicking graafian follicles. Residual hypoplastic testicular tissue was present at the periphery. This is the 19th reported case of testicular juvenile granulosa cell tumor and the fourth with an underlying sex chromosome anomaly, further emphasizing the relationship of this uncommon neoplasm to abnormal sexual or gonadal development.

Mesonephroma of the ovary. A clinical, morphological, and histogenetic appraisal

The clinical and morphological aspects of 32 ovarian tumors of the type considered to be of mesonephric origin have been studied and compared with carcinoma of the endometrium and carcinomas generally considered to arise from the surface covering cells of the ovary. An origin from pluripotential surface epithelium of the ovary or displaced endometrium is supported by a variety of findings: 1. mixed histologic pattern; 2. association with endometriosis, endometrioid carcinoma, and malignant transformation of the surface‐covering cells of the ovary, and 3. histologic similarity to clear cell endometrial carcinoma and of their metastases to papillary cystadenocarcinoma of the ovary.