[Radiation-induced parotid leiomyosarcoma]

INTRODUCTION

First case of radiation-induced parotid leiomyosarcoma.

ANATOMO-CLINICAL OBSERVATION

A 50-year-old woman with a history of cervical irradiation for Hodgkin's lymphoma presented with a right parotid tumefaction. Examination noted a deep adherent pretragal mass with peripheral facial palsy. A total parotidectomy with intra-operative examination and cervical curage was performed. Histopathological analysis concluded to a grade 3 parotid leiomyosarcoma according to the National Federation of Cancer Centers. Adjuvant radiotherapy was performed. After 24 months of follow-up, the patient presented bone and liver metastases without local recurrence.

DISCUSSION

This is the first case of radiation-induced leiomyosarcoma and the 12th case of parotid leiomyosarcoma described in the literature. The management associates surgery with adjuvant radiotherapy. Follow-up is by clinical examination, parotid MRI, and annual thoracoabdominal CT scan to search for metastases. Recurrences occur during the first year in 40 to 64% of cases, and distant metastases in 40 to 60% of cases. The 5-year survival rate is between 10 and 30%.

[Hemangiopericytoma of the infratemporalis fossa: a multi-operated patient]

Hemangiopericytoma (HPC) was diagnosed in a 65-year-old man in 1991. Initially the tumor was located in the maxillary sinus. Resection was followed by multiple recurrences involving the infratemporalis fossa (ITF), the nasopharyngeal region, and the right tonsillar region. Over a 10-year-old period, the histology pattern remained unchanged. Multiple approaches, as described in the literature, were used for resection depending on the site of the recurrence. To data, no malignant structure has been identified. Pain and cranial nerve deficits (V2, V3) have been the main squeleae. This case points out the limitations of radical resection because of the difficulty of the approach to this anatomic region. CT scan must be performed to choose the best access route depending on the primary site of the tumor and its extension.

[Value of a computer-assisted screening method (PAPNET) for the detection of infectious cervico-uterine smears]

There have been several reports regarding the accuracy of the PAPNET system applied to the screening for cancerous and precancerous lesions. Based on neuronal networks, this computerized tool was initially trained to select atypical cells. It has been approved in the USA for the re-screening of cervical smears for quality assurance. However, its particular behaviour has not been frequently studied when the system is designed to detect frequent infectious organisms. We report the results of re-screening of 42 inflammatory cervico-uterine smears by the PAPNET system. The computerized images were reviewed by two different pathologists, with complete agreement between the two observers in 39 cases. Infectious organisms were detected in only 66% of cases. Trichomonas, mycoses and Gardnerella were diagnosed in 63%, 56% and 87% of cases respectively. No herpetic lesions were identified. The low accuracy of the PAPNET system in the diagnosis of infectious cervico-uterine smears should be taken into account if this system is developed as an exclusive pre-screening method.

Destructive polyarthritis due to a group B streptococcus

A new case of destructive polyarthritis due to a Group B streptococcus is reported. The patient was a 55-year-old male whose predominantly axial manifestations in the absence of evidence of an infection initially suggested psoriatic arthritis. Although rare, Group B streptococcal arthritis has been reported outside the postpartal and neonatal periods. Monoarthritis with a favorable outcome has been the most common clinical pattern. Several cases of destructive polyarthritis with axial involvement have been reported in which the joint destruction and longer time to diagnosis as compared with monoarticular forms resulted in permanent functional impairment.

[Increase of alpha-fetoprotein in pancreatic endocrine tumors with hepatic metastases. Apropos of 2 cases]

We report two cases of metastatic non-functioning pancreatic endocrine tumour with very elevated plasma levels of alpha-fetoprotein. In these two cases, serial plasma levels of alpha-fetoprotein, initially normal, correlated well with hepatic tumour progression and were associated with fatal outcome. These results suggest that elevated plasma concentration of alpha-fetoprotein may be caused by metastatic pancreatic endocrine tumour and than alpha-fetoprotein serial measurement may be useful in prognostic evaluation.

Monomorphic and polymorphic carbohydrate antigens on pig tissues: implications for organ xenotransplantation in the pig-to-human model

The existence of the alpha Gal epitope in 137 pigs belonging to 23 different breeds suggests that this antigen is either monomorphic or occurs at a high incidence in the porcine species. Its histological location at the surface of pig vascular endothelial cells makes it a target for human natural anti-alpha Gal antibodies and complement, which may be responsible for the hyperacute vascular rejection of transplanted pig organs. The precursor carbohydrate chain (N-acetyllactosamine) and NeuAc-substituted epitopes are also exposed at the surface of pig vascular endothelium and were found in all pigs in this study. However, humans also have these two epitopes on vascular endothelium and, consequently, have not made natural antibodies against these carbohydrate antigens. Therefore, these two pig epitopes cannot be the main target of the hyperacute vascular rejection process. Three pig phenotypes-A+ (51%), A:H+ (38%), and A-H- I+ (11%) were identified among 37 Large-white pigs by the presence of polymorphic A, H, and I carbohydrate antigens on the brush border of the surface epithelium of small intestine. These antigens were also present in other exocrine secretions but were not detected on vascular endothelium of the same pigs, suggesting that they are not involved in the hyperacute vascular rejection, although the pig A tissue antigen can induce an immune response in 0 or B blood group recipients. Once the problem of the initial hyperacute vascular rejection directed against the alpha Gal epitope is overcome, typing donor pigs for A, H, and I, as well as for the protein swine leukocyte antigens (SLA) and other pig antigens, may help in elucidating antigens involved in acute or chronic xenograft rejection.

Alpha-3-fucosyltransferases and their glycoconjugate antigen products in the developing human kidney

BACKGROUND

Three patterns of alpha-3-fucosyltransferase activity have been described in human adult tissues with different acceptor specificity: myeloid, plasma and Lewis. Five- to ten-week embryos express the myeloid enzyme in all tissues tested, then this enzyme is replaced by plasma or Lewis enzymes, with the exception of leukocytes that continue to express the myeloid form of the enzyme in the adult. These enzymes have not been studied as yet in the developing human kidney.

EXPERIMENTAL DESIGN

The three different alpha-3-fucosyltransferases were studied in homogenates of mesonephros and metanephros with synthetic oligosaccharide acceptors. The oligosaccharide precursors and products of these enzymes (precursor, H, Le(a), sialyl-Le(a) and Le(b) for type 1 and precursor, H, Le(x), sialyl-Le(x) and Le(y) for type 2) were localized by immunofluorescence with specific antibodies.

RESULTS

Only the myeloid alpha-3-fucosyltransferase is detected at 5 weeks in mesonephros and it disappears at 8 weeks. In metanephros, the myeloid enzyme alone is detected between weeks 6 and 8. The plasma enzyme then appears and only at the last trimester of gestation does the Lewis enzyme appear. Three histologic patterns that are concordant with the expression of the alpha-3-fucosyltransferases are observed: I. Inducer, S-shaped body, Bellini and calyce express Le(x) at an early stage when, only the myeloid alpha-3-fucosyltransferase is detected; II. Later, the proximal tubules and descending limbs of Henle's loop express Le(x) (week 9) and sialyl-Le(x) (week 16) when the plasma alpha-3-fucosyltransferase appears; III. Calyceal and collecting systems always express Le(x) and after week 12 Le(a) and Le(b) appear, in accordance with the late appearance of Lewis alpha-3/4-fucosyltransferase.

CONCLUSIONS

The sequential appearance of enzymes and their products suggests that during renal organogenesis the myeloid alpha-3-fucosyltransferase is progressively replaced by the plasma enzyme in the proximal tubules and later by the Lewis enzyme in Bellini's ducts and calyce.

[The metastatic liver: a rare cause of hepatocellular insufficiency]

Liver metastases are frequent, often large and sometimes very late in skin or choroid metastatic melanoma. Hepatic failure is a rarely described complication in metastatic liver melanoma. We report a case of liver failure in a metastatic liver melanoma in a woman 76 years old, treated 16 years before for a choroid melanoma. About this case, we discuss the frequency, the location of primitive tumors and mechanism of liver failure in metastatic liver.

[Osteocalcin and anomalies of cellular immunity in rheumatoid polyarthritis]

Spinal and peripheral skeletal demineralisation is sometimes observed in rheumatoid arthritis (RA). Numerous studies have shown the role of osteoclasts in its genesis, but few studies have been conducted to demonstrate a functional anomaly of osteoblasts. Synthesized by osteoblasts, osteocalcin enables to approach the osteoblastic activity, through titration of its serum level. In 31 patients suffering from erosive classical RA, we titrated the serum osteocalcin. In 9 cases, we found a definite decrease of the serum osteocalcin levels. There was a statistically significant difference between these 9 patients and the 21 others, in the presence of anomalies of the CD4/CD8 lymphocytic ratio, the presence of extra-articular manifestations, a high level of rheumatoid factors, class IgM, with an immuno-enzymatic technique. On the contrary, there was no difference regarding the mean duration of the RA course, the mean age, calcemia, and alkaline phosphatases level. Thus, in the course of severe clinical and immunological rheumatoid arthritis, an anomaly of cellular immunity was observed associated with abnormal serum osteocalcin levels. The exact mechanism of this decrease remains to be specified. Other prospective studies are necessary to confirm this preliminary research.