Bahig M. Shehata

Clonal relationship between precursor T-lymphoblastic leukaemia/lymphoma and Langerhans-cell histiocytosis

1but the biological basis for this link is unknown. We report two cases of Langerhans-cell histiocytosis arising in the context of precursor T-lymphoblastic leukaemia/lymphoma. The Langerhans-cell histiocytosis cells and the precursor T-lymphoblastic leukaemia/lymphoma cells had identical rearrangements of the gene for T-cell receptor � , confirming a clonal relation between the two neoplastic diseases. In April, 1996, a 5-year-old boy presented with a mediastinal mass and a white-cell count of 2·9� 10 9 /L. Bone-marrow aspiration showed precursor T-cell acute lymphoblastic leukaemia; cerebrospinal fluid was negative. He had a complete response to the BerlinFrankfurt-Munster middle-risk schedule. However, from August, 1998, to October, 1998, he developed multiple penile lesions and a biopsy sample showed Langerhans-cell histiocytosis. Between 1998 and 2002 he received several chemotherapeutic regimens and radiotherapy (total dose 44·8 Gy), without a sustained complete response. Regimens included: etoposide and prednisolone; combinations of topical chlormethine, indometacin, betamethasone-depot, vinblastine, thalidomide, etanercept, and intralesional methylprednisolone; mercaptopurine, vinblastine, and 500 mg/m 2 metho

Placental findings in singleton stillbirths

OBJECTIVE: To compare placental lesions for stillbirth cases and live birth controls in a population-based study. METHODS: Pathologic examinations were performed on placentas from singleton pregnancies using a standard protocol. Data were analyzed overall and within gestational age groups at delivery. RESULTS: Placentas from 518 stillbirths and 1,200 live births were studied. Single umbilical artery was present in 7.7% of stillbirths and 1.7% of live births, velamentous cord insertion was present in 5% of stillbirths and 1.1% of live births, diffuse terminal villous immaturity was present in 10.3% of stillbirths and 2.3% of live births, inflammation (eg, acute chorioamnionitis of placental membranes) was present in 30.4% of stillbirths and 12% of live births, vascular degenerative changes in chorionic plate were present in 55.7% of stillbirths and 0.5% of live births, retroplacental hematoma was present in 23.8% of stillbirths and 4.2% of live births, intraparenchymal thrombi was present in 19.7% of stillbirths and 13.3% of live births, parenchymal infarction was present in 10.9% of stillbirths and 4.4% of live births, fibrin deposition was present in 9.2% of stillbirths and 1.5% of live births, fetal vascular thrombi was present in 23% of stillbirths and 7% of live births, avascular villi was present in 7.6% of stillbirths and 2.0% of live births, and hydrops was present in 6.4% of stillbirths and 1.0% of live births. Among stillbirths, inflammation and retroplacental hematoma were more common in placentas from early deliveries, whereas thrombotic lesions were more common in later gestation. Inflammatory lesions were especially common in early live births. CONCLUSIONS: Placental lesions were highly associated with stillbirth compared with live births. All lesions associated with stillbirth were found in live births but often with variations by gestational age at delivery. Knowledge of lesion prevalence within gestational age groups in both stillbirths and live birth controls contributes to an understanding of the association between placental abnormality and stillbirth. LEVEL OF EVIDENCE: II

Histiocytoid Cardiomyopathy: Three New Cases and a Review of the Literature

ABSTRACT Histiocytoid cardiomyopathy (HC), a rare arrhythmogenic disorder, presents as difficult-to-control arrhythmias or sudden death in infants and children, particularly girls. Three cases are described with autopsy findings. In two cases, yellow-tan nodules were grossly visible in the myocardium; in the third case, no gross lesions were identified. Microscopic examination in all three cases revealed multiple, scattered clusters of histiocytoid myocytes which on ultrastructural examination were filled with abnormal mitochondria, scattered lipid droplets, and scanty myofibrils. These pathologic findings are similar to those previously described. The pathogenesis of this entity remains controversial. It was recently proposed that this disorder is X-linked dominant with the associated gene located in the region of Xp22.

Von Hippel-Lindau (VHL) disease: an update on the clinico-pathologic and genetic aspects.

von Hippel-Lindau (VHL) disease is an inherited multisystem familial cancer syndrome caused by mutations of the VHL gene on chromosome 3p25. A wide variety of neoplastic processes are known to be associated with VHL disease. The consequences of the VHL mutations and the pathway for tumor development continue to be elucidated. This paper will detail the variety of tumors associated with VHL disease and discuss the genetic mechanisms that lead to the predisposition for neoplasia.

NUT Midline Carcinoma in a Newborn with Multiorgan Disseminated Tumor and a 2-Year-Old with a Pancreatic/Hepatic Primary

NUT midline carcinoma (NMC) is a rare and aggressive malignant epithelial tumor defined by rearrangement of the NUT gene on chromosome 15. In two thirds of cases, NUT is involved in a balanced translocation with BDR4 on chromosome 19, while in the remaining cases, NUT is rearranged with variant fusion partners such as BRD3. These undifferentiated tumors primarily affect midline structures, usually in the upper aerodigestive tract and mediastinum. Most reported cases have followed a rapidly lethal clinical course. We report the clinical and pathological findings of NMC in the youngest patients identified so far. The 1st case involves a newborn who presented with a supraorbital mass and extensive multiorgan involvement, including the spine, lungs, liver, pancreas, adrenal glands, and subcutaneous tissue. The 2nd patient was a 2-year-old male with an abdominal mass involving the liver and pancreas with pulmonary metastasis. Histopathological analysis of both tumors showed undifferentiated malignant neoplasms, and immunohistochemistry showed positivity for epithelial markers. Both tumors demonstrated t(15;19), and immunohistochemistry with NUT monoclonal antibodies and fluorescent in situ hybridization confirmed NUT rearrangement. The patients died from disease at 1 and 2 months postpresentation. Thus far, 25 cases have been reported, including our 2 current cases. Presentation ages range from 0 to 78 years (mean, 23 years). Herein, we report the 2 youngest reported cases of NMC, including the 1st congenital case and the 1st case arising within the liver/pancreas. Increased awareness and further molecular studies are required for a better understanding of NMC pathobiology and improved therapeutic outcomes.

Angiosarcomas Arising in the Viscera and Soft Tissue of Children and Young Adults: A Clinicopathologic Study of 15 Cases

Angiosarcomas are rare tumors that predominantly affect adult and elderly patients and pursue an aggressive clinical course with high mortality. Although angiosarcomas are well described in a variety of clinical settings, they have been incompletely characterized. We identified 15 high-grade angiosarcomas arising from the viscera and soft tissue of patients 21 years old and younger from institutional and consultation files. Both clinical (patient age, tumor site, tumor size, tumor focality) and histologic features including growth pattern (vasoformative vs. solid), nuclear grade (high vs. low), mitotic rate (mitotic figures/10 high-power fields), necrosis (present vs. absent), and cell shape (epithelioid vs. nonepithelioid) were assessed. Tumors arose in both sexes (8 males; 7 females); age at diagnosis ranged from 3 months to 19 years (mean, 10 y, 5 mo; median, 11 y). Tumors were located in the mediastinum (7), visceral organs (2 in liver, 1 in spleen), breast (2), mesentery (1), pelvis (1), and deep soft tissue of upper extremity (1). Tumor size was documented for 8 patients (range 3.5 to 13 cm; mean 8.1 cm). Eight cases showed epithelioid morphology and 7 cases were primarily spindled. Of 8 cases assessed for podoplanin expression by immunohistochemistry, 7 were negative and 1 was positive. Clinical follow-up was obtained for all patients: 10 (67%) died of disease (range, 27 mo to 11 y; mean, 6 y 8 mo) and 4 patients were alive without disease (range, 27 to 132 mo; mean, 79 mo). Although extremely rare, angiosarcomas do affect children and young adults and this diagnosis should be considered in atypical vascular tumors occurring in the mediastinum and those with brisk mitotic activity and/or necrosis.

Congenital glioblastoma: a clinicopathologic and genetic analysis.

Congenital central nervous system (CNS) tumors are uncommon, accounting for 1% of all childhood brain tumors. They present clinically either at birth or within the first 3 months. Glioblastoma (GBM) only rarely occurs congenitally and has not been fully characterized. We examined clinicopathologic features and genetic alterations of six congenital GBMs. Tumors were seen by neuroimaging as large, complex cerebral hemispheric masses. All showed classic GBM histopathology, including diffuse infiltration, dense cellularity, GFAP‐positivity, high mitotic activity, endothelial proliferation and pseudopalisading necrosis. Neurosurgical procedures and adjuvant therapies varied. Survivals ranged from 4 days to 7.5 years; two of the three long‐term survivors received chemotherapy, whereas the three short‐term survivors did not. Paraffin‐embedded tissue sections were used for FISH analysis of EGFR, chromosomes 9p21 (p16/CDKN2A) and 10q ( PTEN/DMBT1); sequencing of PTEN and TP53; and immunohistochemistry for EGFR and p53. We uncovered 10q deletions in two cases. No EGFR amplifications, 9p21 deletions, or mutations of TP53 or PTEN were noted; however, nuclear p53 immunoreactivity was strong in 5/6 cases. Tumors were either minimally immunoreactive (n = 3) or negative (n = 3) for EGFR. We conclude that congenital GBMs show highly variable survivals. They are genetically distinct from their adult counterparts and show a low frequency of known genetic alterations. Nonetheless, the strong nuclear expression of p53 in these and other pediatric GBMs could indicate that p53 dysregulation is important to tumorigenesis.

Sentinel lymph node biopsy in the pediatric population

BACKGROUND Sentinel lymph node biopsy (SLNB) has only been recently used for childhood neoplasms. METHODS We reviewed all patients younger than 19 years who underwent SLNB for 5 years. RESULTS Twenty patients were identified (11 male, 9 female). Sentinel lymph node biopsy was performed for 10 sarcomas (5 synovial, 3 rhabdomyosarcoma, 1 epitheliod, 1 other); 9 skin neoplasms (4 melanomas, 3 Spitz nevi, 2 melanocytomas); and 1 acinic cell carcinoma. All patients underwent Technetium 99m sulfur microcolloid injection and 4-quadrant subdermal injection with Lymphazurin 1% (Autosuture, Norwalk, Conn). Six patients required either sedation for lymphoscintigraphy. Intraoperative gamma probe was used. Primary lesions were found in lower extremity (n = 8), upper extremity (n = 6), trunk (n = 3), and head and neck (n = 3). The lymphatic basins were inguinal (n = 8), axilla (n = 8), neck (n = 3), and both inguinal and axilla (n = 1). At least one lymph node was identified in each procedure. Of 20 patients, 5 (25%) had metastatic disease (4 skin neoplasms and 1 sarcoma). There were no complications in our series, and all patients are alive with no recurrence at an average follow-up of 2.2 years. CONCLUSIONS Sentinel lymph node biopsy allows for an accurate biopsy in children. However, some younger patients may require sedation, and it may be more challenging to isolate the sentinel node.

Intercellular junctions in Ewing sarcoma/ primitive neuroectodermal tumor : additional evidence of epithelial differentiation

Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) has recently been shown to frequently express cytokeratins, suggesting partial epithelial differentiation. Older ultrastructural studies have documented primitive cell–cell junctions in ES/PNET, reportedly resembling poorly formed desmosomes. Recently, paraffin-reactive antibodies have become available to proteins found in a variety of intercellular junctions indicative of epithelial differentiation, including tight junctions, desmosomes and adherens junctions. We examined intercellular junction protein expression in a large number of genetically confirmed ES/PNET. Formalin-fixed, paraffin-embedded sections from 23 primary and seven recurrent or metastatic cases of genetically confirmed ES/PNET were immunostained for claudin-1 and occludin (tight junction structural proteins), zonula occludens-1 (ZO-1, tight junction linker protein), desmoglein 1/2 (desmosomal adherens protein), desmoplakin (desmosomal structural protein) and E-cadherin (epithelial adherens junction protein), using steam heat-induced epitope retrieval and the Dako Envision system. Cases with >5% positive cells were scored as ‘positive’. Normal colonic epithelium and skin served as external positive controls. Claudin-1 was expressed by 19 of 30 specimens (63%), ZO-1 was expressed by 15 of 29 specimens (51%), and occludin was expressed by three of 28 specimens (11%). In 28 specimens all three tight junction markers were evaluable. In all, 15 samples (54%) expressed only one tight junction marker, and 10 samples (36%) expressed two tight junction markers. No case expressed all three tight junction markers. Desmoglein was expressed in one of 30 (3%) samples. Desmoplakin was expressed in two of 28 (7%) samples. E-cadherin was negative in all cases. Our data suggest that many of the previously described cell–cell junctions in ES/PNET are poorly formed tight junctions, given the high frequency of claudin-1 and ZO-1 expression. This may underestimate the true frequency of tight junction protein expression in ES/PNET, as there are at least 20 different claudins and other ZO proteins. These tight junctions are almost certainly abnormal, given the absence of occludin expression in most cases. Desmosomal and adherens junction protein expression was rare to absent. Our findings provide additional evidence that ES/PNET frequently show partial epithelial differentiation.

Undifferentiated Embryonal Sarcoma of the Liver is Associated with Mesenchymal Hamartoma and Multiple Chromosomal Abnormalities: A Review of Eleven Cases

Undifferentiated embryonal sarcoma (UES) of the liver is a primitive mesenchymal, malignant neoplasm occurring in children. The link between UES and mesenchymal hamartoma (MH) is controversial. Whether they share the same histiogenesis, representing 2 ends of a spectrum, or are distinct entities is unclear. The genetic aberrations of these neoplasms are not well understood, although a common breakpoint (19q13.4) was recently identified. The purpose of this study was to elucidate immunohistochemical markers that may establish a link between the 2 tumors by reviewing cases of UES and MH. Cases of UES from 1990 to 2008 were identified. Clinical demographics were reviewed. Hematoxylin and eosin staining and immunohistochemical staining for vimentin, alpha-1 antitrypsin, and alpha-fetoprotein were performed. Eleven children were diagnosed with UES. Five cases were seen arising in association with MH, and transitional zones were evident. The mean age at presentation was 10 years. To our knowledge, the 11-month-old patient is the youngest reported case of UES in concurrence with MH. All UES tumor cells were positive for vimentin, diastase-resistant periodic acid–Schiff stain, and alpha-1 antitrypsin. Chromosomal analysis of 3 UES cases, 2 arising with MH, showed complex karyotypes with no involvement of 19q13.4. We suggest a continuum between UES and MH. Although a chromosomal anomaly of 19q13.4 was not identified, a submicroscopic involvement of this locus cannot be excluded. Additionally, our analyses suggest that multiple chromosomal aberrations may be associated with the MH/UES spectrum.