Iron metabolism in monochorionic twin pregnancies in relation to twin--twin transfusion syndrome.

Fetal iron metabolism was investigated in monochorionic (MC) twin pregnancies in relation to twin-twin transfusion syndrome (TTTS). Matched maternal and fetal blood samples were obtained both in utero and at birth from MC twins with TTTS (n = 23) and without TTTS (n = 18). In a second group of 30 twin pairs (15 with and 15 without TTTS), liver iron content was assessed by using archived paraffin wax-embedded blocks. Serum ferritin was determined by radioimmunoassay and values are given as gestation independent Z-scores and expressed as mean with 95% confidence intervals. Ferritin concentrations in the recipients were higher than in the donors both in utero (P < 0.01) and at birth (P < 0.01). Fetal serum ferritin in non-TTTS twins were similar to the recipient twins but higher than the donor twins (P < 0.05). A significant association was found between ferritin concentrations, the total red blood cell count and haemoglobin in the TTTS twin pairs (P < 0.01) and the non-TTTS twins as a group (P < 0.01). The total stainable liver iron was comparable between twin pairs in the TTTS and non-TTTS groups. This study fails to provide evidence of iron overload in the recipient and depletion in the donor twins and, thereby, questions the validity of the conventional theory of inter-twin transfusion as the cause of TTTS.

Immunohistochemical detection of myocardial necrosis in stillbirth and neonatal death.

The aims of this study were to determine whether immunohistochemical staining for C9 can demonstrate myocardial necrosis in the fetus and neonate. Hearts from cases of stillbirth or neonatal death with confirmed myocardial necrosis (in neonates) or with ischemic lesions outside the heart (in neonates and stillborns) were stained immunohistochemically with antibodies to C9. All five cases with confirmed myocardial infarction showed positive immunohistochemical staining for C9, largely localized to the infarcted areas. The youngest subject was born at 24 weeks gestation and died at 4 days of age. One of two neonates without myocardial necrosis on H&E staining but with pathological evidence of ischemic lesions elsewhere showed staining of scattered fibers. Six out of ten hearts from macerated stillborn infants showed varying degrees of positive staining. Immunohistochemical staining for C9 detects myocardial necrosis in neonates of a gestational age of 24 weeks or more. C9 is also demonstrable immunohistochemically in macerated stillborns, and this is likely to represent myocardial necrosis. The method is of great potential value in the investigation of cardiac ischemia in the fetal and perinatal period.

Early-onset fetal hydrops and muscle degeneration in siblings due to a novel variant of type IV glycogenosis.

We report on 3 consecutive sib fetuses, presenting at 13, 12, and 13 weeks of gestation, respectively, with fetal hydrops, limb contractures, and akinesia. Autopsy of the first fetus showed subcutaneous fluid collections and severe degeneration of skeletal muscle. Histologic studies demonstrated massive accumulation of diastase-resistant periodic acid-Schiff-positive material in the skeletal muscle cells and epidermal keratinocytes of all 3 fetuses. Enzyme studies of fibroblasts from the 3rd fetus showed deficient activity of glycogen brancher enzyme, indicating that this is a new, severe form of glycogenosis type IV with onset in the early second trimester.

Endocardial fibroelastosis in growth-discordant monozygotic twins.

Two cases of fetal endocardial fibroelastosis are reported in the larger of growth-discordant monozygotic twins. The growth discordance in these two cases is regarded as a manifestation of twin-twin transfusion syndrome, but other causes are considered and the difficulties posed by the observed placental vascular anatomy are discussed. The literature on endocardial fibroelastosis in multiple pregnancy is briefly reviewed, and the relationship of endocardial fibroelastosis to the cardiovascular compromise seen in twin-twin transfusion syndrome is considered.

Bone marrow metastasis in Ewing's sarcoma and peripheral primitive neuroectodermal tumor: An immunohistochemical study.

Bone marrow metastases from small round cell tumors can present diagnostic difficulties. In this study, we assessed the value of immunohistochemistry, using two monoclonal antibodies to CD99, for the diagnosis of metastatic disease in bone marrow trephine specimens from patients with Ewing's sarcoma or primitive neuroectodermal tumor (PNET). The proportions of specimens showing metastases were 10.3% with routine staining and 20.7% with immunohistochemistry. The specimens that were negative on conventional light microscopy and positive with immunohistochemistry all showed other abnormalities. The results do not support the routine use of immunohistochemistry in specimens that are normal by conventional light microscopy, but indicate that useful information may be gained in cases where marrow histology is obscured by fibrosis, necrosis, or distortion artefact. Neither of the two antibodies tested was superior for this purpose.

Fine needle aspiration (FNA) cytology of the breast: the influence of unsatisfactory samples on patient management.

FNA continues to play an important role in the management of patients with breast lesions. However, the reliability and efficiency of the FNA service depends heavily on the quality of the specimens. We have audited the rate of "inadequate FNAs' at intervals over the last 5 years and related our findings to the clinical expertise of the aspirator. We have also correlated the rate of inadequate FNAs with the percentage of patients who had an FNA preceding a definitive diagnosis of cancer. We report trends in the rate of inadequate samples, and subsequent diagnosis of cancer, over a 5-year period. The percentage of breast FNA samples reported as inadequate was 46.8% in 1988-89, falling to 20% in 1991-92 with the introduction of an FNA clinic, and rising to 30.6% in 1993. The rates of cancer following inadequate FNA were 15.7%, 16.1% and 4.2%, respectively, and the percentage of patients with cancer having a preceding inadequate FNA were 37.5%, 13.2% and 7.1%. Possible explanations for the apparent paradox between increasing numbers of inadequate FNA specimens and a falling breast cancer rate are discussed.

The effects of gemeprost on the second trimester fetus.

OBJECTIVE: To determine whether the use of gemeprost is associated with histological changes in the second trimester fetus. SETTING: Histopathology department of a university hospital. DESIGN: Retrospective comparison of histological features in fetuses aborted following maternal administration of gemeprost, with those in fetuses after spontaneous miscarriage. OUTCOME MEASURES: Degree of tissue fragmentation; other histological abnormalities. RESULTS: Significantly greater fragmentation of the liver was found in fetuses exposed to gemeprost (P = 0.046). Nonsignificant effects were found for brain (P = 0.082) and heart (P = 0.183), and no effect was seen on the kidney, adrenal and lung. No other significant histological differences were found between the two groups. CONCLUSIONS: This study is the first to document an effect of gemeprost on the fetus, but confirmation is required in further studies. Other implications are discussed.

An audit of autopsy rates in an inner London general hospital.

Low autopsy rates are of continuing concern to pathologists. The aim of this study was to investigate the reasons why autopsy did not happen, and to determine whether carrying out the investigation and providing some feedback of the results would have any effect on autopsy rates. The main reasons why autopsy did not happen were that junior doctors considered it unnecessary because the diagnosis and cause of death appeared to be well established, and that patients' relatives declined to give permission for autopsy. No increase in autopsy rates was demonstrated, but possible avenues of approach were suggested and these are being implemented.