Neurenteric cyst of the craniocervical junction. Report of three cases.

Neurenteric cysts of the craniocervical junction (CCJ) are very rare lesions. Their origin is the subject of long-standing controversy, but a failure during the embryogenic phase may be responsible for their formation. Accurate histopathological diagnosis may be difficult due to the similarity they share with other cystic lesions such as colloidal cysts, Rathke cysts, and cystic teratomas. Surgical removal is the treatment of choice for intracranial neurenteric cysts, but in some cases, infiltration of the surrounding structures may hinder complete resection. Three cases of neurenteric cysts located at the CCJ are reported.

A new xenograft model of primary central nervous system lymphoma.

The management of primary lymphoma of the central nervous system (PCNSL) remains controversial and patients' outcome dismal. In order to investigate new selective therapeutic strategies in a controlled system, a reproducible model of PCNSL in nude rats was developed and characterized. Human B lymphoma cells (BL2) were implanted in the brain frontal area in New Zealand nude rats through a silastic device sealed to the skull. Fifteen and 30 days post-implantation, animals were sacrificed. An autopsy was performed. Representative brain sections were cut and examined for the presence of lymphoma. Immunohistochemistry was performed for proliferation (MIB1-Ki67), a B-cell marker (L26-CD20), a T-cell marker (UCHL1-CD45RO). The analysis of the brains showed tumor growth in 88% of the rats. No mortality was observed. At autopsy no extracerebral, spinal or cerebellar metastasis were found. Microscopically the brain tumors appeared non-encapsulated, highly vascularized, with a characteristic perivascular and diffuse lymphomatous spread in the parenchyma. Immunohistochemistry showed a marked positivity of the tumor cells for L26. Tumor cells were negative for UCHL1. Mean proliferation rate was 30%. The device was well tolerated and caused no local infection. Controlled studies on PCNSL in animal models are lacking. This PCNSL model in nude rats reproduces the histology and location of human CNS lymphoma. Tumor dimensions are within the resolution limits of CT and MRI and therefore suitable for stereotactic therapy. This model provides a tool to test new chemo and radiotherapeutical strategies in a controlled fashion.

Primary extramedullary plasmacytoma of the liver. A case report.

We report the first case of primary extramedullary plasmacytoma of the liver. The tumor was situated in segment VIII of the liver without extrahepatic extension. Histologically, the tumor was composed of sheets of mature plasma cells with slight atypia in association with proplasmacytes invading the hepatic parenchyma. Neither plasmoblasts nor lymphoplasmacytes were present. Immunohistochemistry demonstrated monoclonal IgG and kappa light-chain expression. In situ hybridization confirmed the monotypic expression of kappa light-chain mRNA. Bone marrow examination revealed no abnormality. After surgery, the IgG kappa spike detected in preoperative plasma samples decreased. The patient is disease free 31 months postoperatively.

Early prenatal diagnosis of ventricular diverticulum complicated by serous pericardial effusion.

An unusual case of apical diverticulum complicated by serous pericardial effusion and diagnosed ultrasonographically at 13 weeks of gestation is described. A therapeutic abortion was induced at 14 weeks and the complete post-mortem examination did not show additional malformation. Cardiac diverticulum is a rare malformation that occurs as an isolated defect or as part of a complex midline thoraco-abdominal defect. Only two prenatally diagnosed cases have been previously reported in the literature and none with associated hydropericardium.

Diprosopia revisited in light of the recognized role of neural crest cells in facial development.

OBJECTIVE: The aim of this study is to compare the theory of embryogenesis of the face with human diprosopia. This peculiar form of conjoined twinning is of great interest because 1) only the facial structures are duplicated and 2) almost all cases have a rather monomorphic pattern. The hypothesis is that an initial duplication of the notochord leads to two neural plates and subsequently duplicated neural crests. In those conditions, derivatives of the neural crests will be partially or totally duplicated; therefore, in diprosopia, the duplicated facial structures would be considered to be neural crest derivatives. If these structures are identical to those that are experimentally demonstrated to be neural crest derivatives in animals, these findings are an argument to apply this theory of facial embryogenesis in man. METHODS: Serial horizontal sections of the face of two diprosopic fetuses (11 and 21 weeks gestation) were studied macro- and microscopically to determine the external and internal structures that are duplicated. Complete postmortem examination was performed in search for additional malformations. RESULTS: The face of both fetuses showed a very similar morphologic pattern with duplication of ocular, nasal, and buccal structures. The nasal fossae and the anterior part of the tongue were also duplicated, albeit the posterior part and the pharyngolaryngeal structures were unique. Additional facial clefts were present in both fetuses. Extrafacial anomalies were represented by a craniorachischisis, two fused vertebral columns and, in the older fetus, by a complex cardiac malformation morphologically identical to malformations induced by removal or grafting of additional cardiac neural crest cells in animals. CONCLUSION: These pathological findings could identify the facial structures that are neural crest derivatives in man. They are similar to those experimentally demonstrated to be neural crest derivatives in animals. In this respect, diprosopia could be considered as the end of a spectrum, whereas the other end is agnathia-holoprosencephaly complex. This assumption has to be discussed, but we want to draw attention to the fact that diprosopia must not be considered as a curious form of conjoined twinning, but as a major means of bringing us a better knowledge of the facial embryogenesis in man.

Idiopathic arterial calcification in a stillborn complicated by pleural hemorrhage and hydrops fetalis.

We report a case of idiopathic arterial calcification in a stillborn. As usually noted in this rare entity, the pregnancy was complicated by a polyhydramnios. The postmortem examination showed generalized arterial calcification, periarticular calcific deposits, and a large pleural hemorrhage. The causes of fetal hydrops in idiopathic infantile calcification are discussed, and, in the present case, the absence of myocardial ischemic lesion suggests that the fetal hydrops and the fetal death could have been caused by the bulky blood clot that was present in the right pleural cavity. The pathogenesis remains undetermined, but a primitive inherent defect of the elastic elements seems to initiate this disorder.

[Cystic adenomatoid malformation of the lung, bilateral renal agenesis and left heart hypoplasia. An unusual association in Potter's syndrome]. / Malformation adénomatoïde kystique du poumon, agénésie rénale bilatérale et hypoplasie du coeur gauche. Une association inhabituelle dans un syndrome de Potter.

We describe an autopsy case of congenital cystic adenomatoid malformation of the lung (CCAM) associated with bilateral renal agenesis. Prenatal ultrasound examination showed additional left heart hypoplastic syndrome. A therapeutic abortion was induced at 23 weeks of gestation. The association CCAM-bilateral renal agenesis is a rare condition (5 cases previously described) which has to be known because of the mitigation effect of the CCAM on the oligohydramnios determined by bilateral renal agenesis. However, this instance is usually associated with oligohydramnios. The pathogenesis of polyhydramnios in isolated CCAM is discussed in regard with these data.

[Analysis of 1410 examinations of fetal pathology at the University Hospitals of Bordeaux]. / Analyse de 1,410 examens foetopathologiques pratiqués au CHU de Bordeaux.

We present a retrospective study of 1,410 fetal pathological examinations performed in the department of pathology of the CHU de Bordeaux. Initially, the recruitment of the cases was limited to the three maternity units of the CHU. Public and private maternities and departments of pediatrics from the whole of Aquitaine (S.W. province) as well as a certain number of neighbouring provinces now send us their material for analysis. Fetal pathological examination is systematically indicated in cases concerning spontaneous abortion, pregnancies terminated after prenatal diagnosis and stillbirths. Autopsies performed on children aged from 0 to 1 year have been included. The same technique has been used for all examinations and the data have been recorded on a computerized system (Centre Régional d'Informatique Hospitalière). Current data analysis for age at death, sex-ratio, maternal age, mode of abortion and pathological conditions are given. We found at least one pathological anomaly in 43.2% of the spontaneously aborted fetuses and stillbirths. Nevertheless, our aim is to demonstrate that foetopathology units can play a role not only for diagnoses having a significant impact on genetic counseling, but also as a database for epidemiological studies.

[Arterial opacification in the anatomo-pathologic test of the fetus]. / Apport de l'opacification artérielle dans l'examen anatomo-pathologique du foetus.

Arteriography provides information that is very useful for planning postmortem examinations of fetuses and stillborn neonates. This was demonstrated in a series of 25 fetal arteriographies performed by catheterization of the umbilical artery. A detailed analysis of systemic and pulmonary arteries was possible. The data thus collected was used to plan the postmortem examination. Furthermore, arteriography provided data on organs damaged by maceration and small caliber vessels that could not be readily submitted to pathologic studies. Arteriography of fetuses or stillborn infants is irreplaceable when permission to perform an autopsy is refused by the parents.

[Craniorachischisis in conjoined "diprosopus" twins. Case report and review of the literature]. / Craniorachischisis chez des jumeaux conjoints "diprosopus". Présentation d'un cas et revue de la littérature.

The pathological features in a case of craniorachischisis with incomplete twinning (diprosopus) are reported. The female fetus was born to a 27-year-old gravida 6, para 3 healthy woman who underwent a medical abortion at 13 week's gestation because of an anencephaly revealed by ultrasound examination. The head showed two fused faces with two mouths, two noses, two lateral completely formed eyes and two medially fused eyes covered by cutaneous tissue. X-ray examination demonstrated the symmetrically doubled spinal column. The brain and the spinal cord were absent (craniorachischisis). The larynx and the oesophagus, the other viscera and the limbs were normal in number, location and morphology as for a female singleton. This case with others from the literature, illustrates the relationship between conjoined twinning, neural tube defects (more particularly anencephaly) and female zygote and constitutes a real entity.