Ultrastructure of primary squamous cell carcinoma of the submandibular gland

Primary squamous cell carcinoma of the submandibular gland is a rare tumor. In this report, the histological and ultrastructural features of a case of primary squamous cell carcinoma arising in the left submandibular gland is presented. Light microscopically, the tumor consisted of well differentiated keratinizing squamous cell nests. Ultrastructurally, the tumor cells were oval or spindle-shaped, and several tumor cells had intracytoplasmic desmosome-like structures, resembling intercellular desmosomes. The majority of the tumor cells contained a large number of intermediate filaments (tonofilaments). Intercellular desmosomes were well developed. No secretory granules were found. These ultrastructural features may enable us to distinguish primary squamous cell carcinoma from mucoepidermoid carcinoma which is often misdiagnosed as squamous cell carcinoma.     

Transient GABA immunoreactivity in cranial nerves of the chick embryo

The distribution and time course of gamma-aminobutyric acid (GABA) immunoreactivity was investigated in the cranium of the chick embryo from 2 to 16 days of incubation (E2-16). A fraction of nerve fibers transiently stains GABA-positive in all cranial motor nerves and in the vestibular nerve. Cranial motor nerves stain GABA-positive from E4 to E11, including neuromuscular junctions at E8-11; labeled fibers are most frequent in the motor trigeminal root (E6-9.5). Substantial GABA staining is present from E4 to E10 in a subpopulation (1-2%) of vestibular ganglion cells. Their peripheral processes are labeled in the vestibular endorgan, predominantly in the posterior crista. Some GABA-positive fibers are present in the olfactory nerve (after E5) and in the optic nerve (after E9.5); their immunoreactivity persists throughout the period investigated. Transient GABA immunoreactivity follows "pioneer" fiber outgrowth and coincides with the formation of early synaptic contacts. GABA-containing neurons may change their neuronal phenotype (loss of GABA expression) or they may be eliminated by embryological cell death. Periods of cell death were determined in cranial ganglia and motor nuclei by aggregations of pycnotic cells in the same embryonic material. The periods of embryonic cell death partly coincide with transient GABA immunoreactivity. The function(s) of transient GABA expression is unknown. Some lines of evidence suggest that GABA has neurotrophic functions in developing cranial nerves or their target tissue. In the developing neuromuscular junction, GABA may be involved in the regulation of acetylcholine receptors.     

Secretory carcinoma of the breast in adults: emphasis on late recurrence and metastasis

Secretory (so-called juvenile) carcinoma of the breast, first described in children, occurs also in adult women, predominantly in the third decade. Less commonly it is seen in older age groups, up to the eighth decade. We report five patients with this tumour; one, a female aged 73, is the oldest age at which the tumour has been recorded, and one is the first report in an adult male in whom the disease recurred after 20 years, only the second recorded death attributable to this tumour type. Secretory carcinoma in adults is potentially more aggressive than in childhood. Nodal metastases are more frequent and sometimes more extensive. Recurrence of tumour after surgery developed in four of our five patients at 3, 8, 15 and 20 years. Slow growth and delayed recurrence are characteristic of many of these tumours. Death from systemic metastases is rare, but may ensue either rapidly or following a long latent period after treatment. Prolonged follow-up is needed to assess accurately the biological behaviour of this tumour.     

Hepatitis B surface antigen and hepatocellular carcinoma in Southern Africa

Summary Most series in Africa show a high percentage of hepatitis B surface Hepatitis antigen in hepatocellular carcinoma. Two groups of cases were investigated in this study. The one was derived from the autopsy material at Baragwanath hospital from subjects who had lived in Soweto, a large Black urban town. The second group consisted of male Black mineworkers generally originating from rural areas. A combination of the aldehydefuchsin stain and immunoperoxidase technique was used. The two groups showed totally different results. The Baragwanath series consisted of 24 hepatocellular carcinomas of which only 4 (17%) were HBsAg positive. Of the 24 cases, 14 had cirrhosis of which 9 were macronodular and 5 micronodular. Ten of these cases showed heavy iron overload. The series of male Black mineworkers comprised 22 cases of which 16 (72%) were HBsAg positive. Twelve of the 22 cases showed a macronodular cirrhosis and there were no micronodular cirrhoses. Only one case showed severe iron overload. These findings delineate two different populations of hepatocellular carcinoma in Southern Africa.     

A case of type I Gaucher disease with cardiopulmonary amyloidosis and chitotriosidase deficiency

We present a case of Merkel cell carcinoma of the thigh diagnosed by conventional histology, immunohistochemistry, electron microscopy and cytogenetics. A unique chromosome 6 trisomy characterized this primary neoplasm, as confirmed by FISH study. The role of chromosome analysis and interphase cytogenetics is emphasized as an adjunct in the subtyping of tumours and their prognostic evaluation.     

鼻咽癌旁上皮细胞核DNA含量分析

应用显微分光光度计测定15例鼻咽癌19处癌旁病变的上皮细胞核DNA含量并与浸润癌相比较。中、重度异型增生上皮细胞核DI及超过2.5c细胞的百分数处于单纯增生+轻度异型增生与浸润癌之间,3组DI及超过2.5c细胞的百分数差异显著。中、重度异型增生以非整倍体为主,其细胞核DNA含量组方图相似于浸润癌。从细胞核DNA含量角度来看,中、重度异型增生是重要的癌前病变。     

Carcinoma of the alimentary canal — A statistical study based on autopsy data from 1928 to 1972

Summary An analysis of autopsy data shows that during the period 1928–1972 the relative frequency of carcinoma of the stomach has remained practically unchanged. A similar trend is apparant from the mortality statistics for Vienna from 1955 to 1972. Whereas for the lower and middle age groups there is a real decrease during the period 1928–1952, an opposite trend is visible for the highest age group. The stomach and the lower parts of the large intestine are the most frequent sites of carcinoma of the alimentary canal. The frequency distribution is explained on the basis of the contact hypothesis.     

Lymphoepithelioma-like carcinoma of the bladder: three cases with clinicopathological and p53 protein expression study

Lymphoepithelioma-like carcinoma of the bladder is an uncommon neoplasm, of which 49 cases have been described in the English literature, none of which has been studied for p53 protein expression. We studied three muscle-infiltrating cases of this tumor using immunohistochemical, in situ hybridization and polymerase chain reaction (PCR) methods. The three cases were positive for epithelial markers and negative for lymphoid antigens in the tumoral syncytial areas. The intensive infiltrate of small cells was negative for epithelial and positive for lymphoid markers. This population was mainly made up of cytotoxic T-lymphocytes, positive for TIA-1. p53 protein was intensely positive in more than 90% of the epithelial component nuclei, being negative in the lymphoid cells. PCR study did not show mutations on p53. Both lymphocytes and epithelium were negative for Epstein–Barr virus markers, such as the latent membrane protein and EBER (Epstein–Barr-encoded RNA). The prognosis was very good after radiotherapy and chemotherapy treatment, preserving the bladder despite the muscle infiltration. The presence of an intense cytotoxic T-lymphocyte population may be related to this good prognosis. Both aspects, p53 protein status and T-lymphoid population, had never been studied before in bladder lymphoepithelioma-like carcinoma.     

Human papillomavirus infection in Egyptian esophageal carcinoma: correlation with p53, p21, mdm2, C-erbB2 and impact on survival

The etiological role of human papillomavirus (HPV) in esophageal carcinoma (EC) in relation to p53, mdm2, p21(waf), c-erbB2 and the overall survival (OS) rate was investigated. Tumor and normal tissues from 50 EC were evaluated by polymerase chain reaction and InnoLiPA for HPV. Single strand conformation polymorphism/sequencing were used to detect p53 gene mutations. Immunohistochemistry was performed to determine p53, mdm2, p21(waf)and c-erbB2 expression. Human papillomavirus was detected in 54% of tumors and in 24% of normal tissues. p53, mdm2 and c-erbB2 overexpression was detected in 68%, 70% and 60% of tumors and in 14%, 16% and 10% of normal samples, whereas loss of p21(waf) was evident in 64% of tumors. p53 mutations were detected in 20% of cases. Exon 8 and 5 showed the highest mutation rate (40% each), followed by exons 6 and 7 (10% each). There was a significant correlation between HPV and p53, mdm2, c-erbB2 overexpression. The OS was significantly associated with overexpression of p53 and loss of p21(waf). Human papillomavirus infection is frequent in Egyptian EC. Both p53-dependent and p53-independent pathways seem to be involved in HPV-associated EC. mdm2 and c-erbB2 are possible targets for HPV in the p53-independent pathway. However, only advanced stage and aberrant expression of p53 and p21(waf) are independent prognostic markers.     

Morphogenesis of the bovine rete testis: extratesticular rete, mesonephros and establishment of the definitive urogenital junction

The development of the extratesticular rete, the regression of the mesonephros and the establishment of the urogenital junction between rete testis and efferent ductules were investigated in 67 bovine embryos and fetuses collected in the period from day 29 through day 250 post conception. The results were obtained by immunohistochemistry and by the study of semithin sections. At about day 30, the large mesonephros contains a peculiar Malpighian body in its cranial part, generally referred to as the mesonephric giant corpuscle, which is connected to the Wolffian duct by a series of well-developed and functioning mesonephric tubules. This set of primary mesonephric tubules, however, will not participate in the formation of the definitive urogenital junction, but will regress and soon disappear completely. The efferent ductules in the bovine are represented by another set of secondary mesonephric tubules that grow out from the dorsal aspect of the mesonephric giant corpuscle at about day 50. Transiently, the lumina of the sprouting efferent ductules are plugged by invading intraductular blood vessels, probably representing rudimentary glomeruli. The proximal portions of the newly-formed efferent ductules establish side-to-end contacts with extensions of the extratesticular rete that has bypassed the regressing giant corpuscle. At 85 days, the efferent ductules have reached the Wolffian duct and open into it. At 150 days, the channels of the extratesticular rete display a patent lumen and now form end-to-end anastomoses with the efferent ductules. The proliferating mesenchymal cells surrounding the epithelia of the efferent ductules have arranged in several concentric layers at about 85 days. These mesenchymal cells are the precursors of the periductular musculature and are reached by the first nerve fibers at about day 130. Accepted: 13 December 2000