An unusual heterotopia of pyloric glands of the stomach with inverted downgrowth.

A rarely reported, large heterotopia of gastric glands in the submucosal layer of the stomach is observed in a 79 year old Japanese man with early gastric cancer. Histologically, it consists of marked hyperplasia of benign foveolar-type epithelia and tubular glands which instead of growing upwards grow downwards into the submucosa. Immunohistochemically, many gastrin-positive G cells are observed within it, indicating the existence of independent pyloric-type glands from the surrounding mucosa with intestinal metaplasia. Muscle actin-positive fascicles, derived from the muscularis mucosae, are demonstrated to branch into it and to encapsulate it. This result suggests that the present lesion may not represent a truly submucosal ectopic location, but an inverted downgrowth of the mucosa into the submucosa, thus resembling an inverted polyp of the colon. An awareness of this unique lesion is important in order that it not be mistaken for a submucosal extension of the primary adenocarcinoma.

Enteric nervous system and endocrine cells demonstrated in the gut in teratomas.

A case of retroperitoneal teratoma, showing considerable morphological development presented as an encapsulated and pedunculated tumour with a seemingly mature intestinal loop. Markedly complex intramural nerve plexuses and numerous epithelial endocrine cells were revealed immunohistochemically in the gut tissue. Ten other mature teratomas containing gastrointestinal tissues were examined for comparison, but neither intramural ganglia nor nervous networks were found in the gut components, despite the presence of amine- and/or peptide-containing endocrine cells in all intestinal mucosa linings. Enteric endocrine cells were found to occur irrespective of the differentiation of intestinal layers or the occurrence of neural elements. These findings suggest that the epithelial endocrine cells of intestinal mucosa do not have the same origin as enteric neurons, but are rather of endodermal origin. This invertebrate well-formed teratoma, containing a highly organized enteric nervous system, suggests that teratoma and fetus in fetus are related entities distinguished by the presence of a vertebral axis.

The histological features of splenosis.

This study presents a detailed histological analysis of two cases of splenosis, including one of the largest nodules to be reported. Splenosis may exhibit red and white pulp that appears histologically and immunohistochemically normal by routine methods, and a well-developed capsule and trabeculae may form. The capsule may be thicker than in the normal spleen but is otherwise indistinguishable and may contain fibrous, elastic and smooth muscle elements. These findings are in contrast to previously published works which have described poorly-developed white pulp, capsule and trabeculae in splenosis. The histological pattern may depend on the blood supply to the autotransplanted splenic tissue in the early days after implantation. The close resemblance that splenosis may show to an accessory spleen suggests that histological examination may have a limited role in the distinction between these two conditions.

Heterotopic pancreas of the stomach. Histogenesis and immunohistochemistry.

Ordinary histological investigation has suggested that heterotopic pancreas of the stomach may have two types of histogenesis; one is development from immigrated fetal pancreas tissue, and the other is development from primitive gastric mucosal epithelium following penetration into the submucosa with subsequent erroneous differentiation into pancreas tissue. It is suspected that type-I lesions include the majority of cases caused by immigration from fetal pancreas, and that some type-II cases arise through erroneous differentiation of primitive gastric mucosal epithelium. With regard to immunohistochemical findings, cells positive for pancreatic polypeptide and amylase were much more numerous in the acini of type-I cases compared with type-II cases. Positive cells were found not infrequently in the acini of type-II cases after staining for pancreatic polypeptide, insulin, glucagon, somatostatin, serotonin, and gastrin. On the other hand, a small number of cells in islets were not infrequently positive for alpha 1-antitrypsin, alpha 1-antichymotrypsin, and amylase. It is considered that in the heterotopic pancreas, ductal cells have the potential to differentiate into acinar cells and islet cells, as is the cases in the orthotopic pancreas.

Gonadotropin-releasing hormone-induced accumulation of follicle-stimulating hormone beta-subunit messenger ribonucleic acid in adenohypophysial cells developing in an ectopic position.

We investigated the influence of LHRH on the accumulation of FSH beta messenger RNA (mRNA) in anterior pituitary glands removed from hamster pups less than 36 h old and transplanted beneath the renal capsules of adult male hamsters (hosts). Three experiments were performed in which some hosts were injected sc with LHRH (1 microgram/injection) and others were injected with vehicle. Injections were begun in the afternoon of the day of transplantation (day 1) and were given at 0800 and 1700 h for 6 days and at 0800 h on the eighth day. An additional experiment was performed in which adult male hamsters not bearing allografts were injected with the same regimen of LHRH or vehicle. The hamsters were decapitated on the eighth day of the study, 2 h after the last injection. The allografts, adenohypophyses of the hosts, adenohypophyses of hamsters without allografts, and adenohypophyses of normal adult male rats were removed and frozen on dry ice immediately. Additionally, adenohypophyses were collected from hamster pups less than 36 h old and 8 and 15 days of age. Total RNAs from some pooled specimens were electrophoresed on a formaldehyde-agarose gel. After transfer to Nytran, the RNAs were hybridized sequentially to complementary DNAs for rat FSH beta and hamster beta-actin. The rat FSH beta complementary DNA probe hybridized to a single RNA (approximately 1.7 Kb) in rat adenohypophyses. It predominantly hybridized to RNA of approximately 1.7 Kb from hamster adenohypophyses. Sometimes it hybridized to RNAs ranging in size from 0.5 Kb to 1.7 kb. The hybridization signals for all samples obtained from dot blot analyses were quantitated and normalized to the signals for beta-actin. The hybridization signals obtained from adenohypophyses of hamsters of different ages increased from 36 h of age to adulthood. The hybridization signal obtained from adenohypophyses of hamsters less than 36 h old (the same age as the donor hamsters) was similar to the hybridization signal obtained from allografts in vehicle-treated hamsters. The relative levels of FSH beta mRNA in allografts of LHRH-treated hosts were: 1) greater than the relative levels in adenohypophyses of hamsters less than 36 h old (P less than 0.05) and in allografts in vehicle-treated hamsters (P less than 0.05), 2) greater than the relative levels in adenohypophyses of 8-day-old hamsters (P less than 0.05), and 3) not different compared to the relative levels in adenohypophyses of 15-day-old hamsters and adult male hamsters.(ABSTRACT TRUNCATED AT 400 WORDS)

Cutaneous ganglion cell choristoma. Report of a case.

We describe the histological, immunohistochemical, and ultrastructural findings of a cutaneous tumour composed of ganglion cells, without any other proliferating component. As ganglion cells are not normal components of the skin, we propose the term "ganglion cell choristoma" for this lesion. The differential diagnosis of related lesions such as cutaneous ganglioneuroma, well-differentiated metastases from neuroblastoma, autonomic ganglia entrapped by neurofibroma, and reactive processes, and the possible histogenesis of ganglion cell choristoma are discussed.

Heterotopic glial nodules: a light microscopic and immunohistochemical study.

The clinical, light microscopic and immunohistochemical features of 14 heterotopic glial nodules are described. In keeping with previous experience, most cases were located around the nose and had been present since birth. However, several lesions presented as cutaneous nodules elsewhere and, in some, presentation was delayed into childhood or even adulthood. The histological diagnosis is usually uncomplicated, but we draw attention to a variant with a markedly sclerosed stroma in which the glial cells are relatively inconspicuous. Such lesions tend to be found in older subjects and can cause problems in diagnosis. We emphasize the value of immunohistochemical demonstration of glial fibrillary acidic protein in the diagnosis of these lesions, especially in the sclerotic variant. Other immunohistochemical features include the presence of axons in most cases and cell bodies in some, emphasizing the mixed nature of these lesions. A meningeal component could not be demonstrated immunohistochemically, even at the edge of the lesions.

Demonstration of glial fibrillary acidic (GFA) protein by electron immunocytochemistry in the granular cells of a choristoma of the neurohypophysis.

The origin of the nests of granular cells comprising choristomas of the infundibular process and the stalk of the pituitary gland is controversial. Using electron microscopic immunocytochemistry, the astrocytic marker, glial fibrillary acid protein (GFAP), has been demonstrated diffusely in the cytoplasm of some of the granular cells, but not within the granules or cellular organelles of some of the granular cells. Cytoplasmic filaments were not detected in these granular cells, but cells with abundant filaments extended processes between the granular cells. These filament-rich cells stained much more intensely for GFAP than the positively staining granular cells. The expression of GFAP by the granular cells and the filament-containing cells between them in the pituitary implies an astrocytic origin for both cell types, but the absence of filaments in the granular cells suggests that the GFAP is in an unpolymerized (soluble) form. The granular cell is likely to represent a transitional cell type of astrocytic origin in which the glial filaments have undergone partial or complete degradation.

Heterotopic central neural tissue of the tongue.

A rare case is reported of a pedunculated tumor containing heterotopic central neural tissue in the tongue of a 3-month-old girl. The lesion was located near the foramen caecum and was composed of glial cells, ependymal cells, a small number of neuronal cells and a relatively thick peripheral nerve.