Primary mediastinal large B-cell lymphoma: Outcome of a series of pediatric patients treated with high-dose methotrexate and cytarabine plus anti-CD20.

Between 2007 and 2013, 13 children diagnosed with primary mediastinal large B-cell lymphoma (PMLBL) were treated according to a modified version of AIEOP (Associazione Italiana Ematologia Oncologia Pediatrica) LNH-97 protocol based on high-dose methotrexate, anthracyclines, and addition of anti-CD20. Ten patients achieved a continuous complete remission with front-line therapy. The overall 5-year survival was 91.7%, and event-free survival was 83.9%, with only one patient dying of progressive disease. Despite the few cases, these results demonstrate that this therapy, which includes anti-CD20, given in a multicenter setting, is feasible with acceptable toxicity in children with PMLBL.

Could past Chlamydial vascular infection promote the dissemination of Chlamydia pneumoniae to the brain?

Chlamydia pneumoniae, a pathogen responsible for respiratory tract infections, has been associated with atherosclerosis which, along with hypertension, hyperlipidemia, cardiovascular and/or cerebrovascular ischemia and stroke, is a risk factor for chronic neurological disorders. Several studies have demonstrated the ability of C. pneumoniae to disseminate from lungs to arteries through peripheral blood mononuclear cells. Once inside the vascular tissue, C. pneumoniae infection may disseminate via peripheral monocytes to the brain over the intact blood-brain barrier, and contribute to the development of chronic neurological disorders. The aim of our study was to evaluate whether past C. pneumoniae vascular infection may promote the dissemination of this microorganism to the brain, therefore we investigated the presence of C. pneumoniae in post-mortem brain tissue specimens of patients with past chlamydial vascular infection. Seventy six post-mortem brain tissue specimens from 19 patients with past chlamydial vascular infection were investigated for the presence of C. pneumoniae by immunohistochemistry, polymerase chain reaction, in situ polymerase chain reaction and in situ reverse transcription polymerase chain reaction. As control, 28 brain tissue specimens were taken from 7 age and sex matched subjects without chlamydial infection. C. pneumoniae was detected in 16 (84.2%) out of 19 patients with chlamydial vascular infection whereas it was not detected in control subjects (p= 0.0002). In conclusion, the main result of our study is the evidence that a chlamydial vascular infection can disseminate to the brain. It will be important for current and future researches to perform large-scale prospective studies on cardiovascular patients with chlamydial vascular infection in order to evaluate the long-term pathological alterations of the brain.

Prevalence and clinical implications of bone marrow involvement in pediatric anaplastic large cell lymphoma.

Anaplastic large cell lymphoma (ALCL) harbors the reciprocal chromosomal translocation t(2;5)(p23;q35) in approximately 80% of the cases. The genes involved are nucleophosmin (NPM) and anaplastic lymphoma kinase (ALK) and the resulting chimeric NPM-ALK protein is thought to play a key role in the pathogenesis of t(2;5) positive ALCL. Few data on bone marrow (BM) involvement in ALCL have been published and they mostly rely on morphological examination of BM smears. We studied 52 ALCL for NPM-ALK expression by RT-PCR: 47/52 biopsies were positive. In 41 of the 47 cases we obtained the BM at diagnosis and investigated the prevalence of minimal BM infiltration by RT-PCR and real-time PCR. Minimal disseminated disease was positive in 25/41 patients (61%), of whom six had morphologically infiltrated BM. Survival analysis demonstrated a 5-year progression-free survival of 41 +/- 11% for patients with molecularly positive BM vs 100% for patients with negative BM (P = 0.001). These results suggest that minimal BM involvement at diagnosis is a common event in pediatric ALCL and that minimal BM disease monitoring could identify patients at risk of relapse.

Expression and parental imprinting of the H19 gene in human rhabdomyosarcoma.

The expression of Insulin-like Growth Factor 2 (IGF-2) and H19, two genes located on human chromosome 11p15 and provided with cell growth modulating activity, is regulated by parental imprinting, in that the activity of their alleles is dependent on the parental origin. Parental bias in the genetic alterations of chromosome 11p15 observed in several pediatric cancers suggests the involvement of imprinted genes in tumor development. We have previously reported that the number of functional IGF-2 alleles is frequently increased in rhabdomyosarcoma (RMS), as a consequence of either relaxation of imprinting (LOI) or gene duplication. Here we show that the expression of the H19 gene is significantly suppressed with respect to normal muscle tissue in 13 out of 15 rhabdomyosarcomas with embryonal histology (ERMS) and in three out of 11 rhabdomyosarcomas classified as alveolar subtype (ARMS). Since a growth-inhibitory activity has been found associated with the H19 gene, the extinction of its expression can contribute to RMS development. Parental imprinting of the H19 gene was found conserved in all informative RMSs, including those whose ICF-2 imprinting was relaxed, indicating that LOI is a gene-specific event. Seven ERMSs and one ARMS displaying low H19 RNA levels showed an underrepresentation of the expressed allele in their genotype. This result is consistent with the paternal imprinting of the H19 gene and with the preferential loss of the maternal 11p15 alleles in these neoplasms. Low H19 expression was also found in four out of eight RMSs retaining the heterozygosity at 11p15, but showing IGF-2 LOI. These findings suggest that the genetic and epigenetic alterations affecting chromosome 11p15 in a high number of RMSs cause deregulation of more than one imprinted gene, possibly affecting tumor growth, including the extinction of H19 expression and an increase in the number of active IGF-2 alleles.

Clinical relevance of DNA ploidy and proliferative activity in childhood rhabdomyosarcoma: a retrospective analysis of patients enrolled onto the Italian Cooperative Rhabdomyosarcoma Study RMS88.

PURPOSE: Evaluation of the possible clinical relevance of DNA ploidy and proliferative activity assessed as S-phase fraction (SPF) in childhood rhabdomyosarcoma (RMS). PATIENTS AND METHODS: We conducted a retrospective study on 59 RMS patients enrolled onto the ICS-RMS88 protocol (seven botryoid, 35 embryonal, and 17 alveolar RMS), for which formalin-fixed paraffin-embedded (FFPE) tissue was available. Nuclear suspensions for cytometric investigation were obtained using a mechanical disaggregation. Tumors were distinguished according to their DNA index (DI) value as follows: diploid (0.9 < DI < 1.1), hyperdiploid (1.1 < or = DI < 1.8 or DI > or = 2.2), and tetraploid (1.8 < or = DI < 2.2); for analysis of SPF, a cutoff value of 14% was used. RESULTS: DNA histograms were diploid in 19 (33%) cases, hyperdiploid in 29 (49%), and tetraploid in 10 (32%). One patient showed both a hyperdiploid and a tetraploid peak. The 5-year overall survival (OS) rate by ploidy status was 73% in hyperdiploid patients as compared with 33% and 25% in diploid and tetraploid patients, respectively (P = .0012). A striking difference emerged when the 5-year OS for the combined diploid and tetraploid RMS groups was compared with survival of the hyperdiploid RMS group: 30% versus 73%, respectively (P = .0006). In addition, the SPF was prognostically relevant: 5-year OS by SPF less than or greater than 14% was 70% and 36%, respectively (P = .009). Multivariate analysis confirmed the importance of DNA content (P = .0006) and SPF (P = .034) in predicting survival. CONCLUSION: These findings confirm that ploidy and SPF are important new prognostic factors that are able to identify selected groups of patients at high risk of treatment failure, even if the tumor's presentation is favorable according to standard criteria.

Prospective analysis of minimal bone marrow infiltration in pediatric Burkitt's lymphomas by long-distance polymerase chain reaction for t(8;14)(q24;q32).

The chromosomal translocation t(8;14)(q24;q32) represents a characteristic marker for Burkitt's lymphoma (BL). This translocation involves the MYC oncogene on chromosome 8 and the immunoglobulin heavy-chain (IgH) locus on chromosome 14. Since the translocation does not produce a fusion gene, we established a long-distance polymerase chain reaction (LD-PCR) assay that can detect the t(8;14) at the genomic level. The sensitivity of the LD-PCR was 10(-4). We used the LD-PCR assay to prospectively study 78 BL patients and found a specific PCR product in 52 of them. Among the 52 positive patients, we could test both the tumor and the bone marrow (BM) at diagnosis in 33 and determined the prevalence of minimal disseminated disease (MDD) at diagnosis. In 12/33 patients, BM was positive by LD-PCR and in 10 of them we conducted a study of minimal residual disease (MRD). Eight out of 10 children showed a clearance of MRD after one cycle of chemotherapy. The only two patients who did not achieve a negative MRD status died of disease progression. The comparative analysis of sensitivity of BM aspirate, BM biopsy and LD-PCR in t(8;14)-positive patients demonstrated a superiority of the molecular method in the assessment of MDD. The LD-PCR for t(8;14) is an important tool to study minimal BM infiltration at diagnosis and to determine its response kinetics in BL.

Omental mesenteric myxoid hamartoma, a subtype of inflammatory myofibroblastic tumor? Considerations based on the histopathological evaluation of four cases.

Omental mesenteric myxoid hamartoma (OMH) is a distinctive myxoid lesion of infancy, characterized by a benign clinical behavior. In the current World Health Organization (WHO) classification of soft tissue tumors, it is considered as part of the morphologic spectrum of inflammatory myofibroblastic tumors (IMT), but this relationship with IMT is still subject to debate. Four lesions with histologic features of OMH occurring in newborns and toddlers are described and compared with classic, ALK-positive IMT. All OMH showed a peculiar dot-like immunostaining for ALK, which, in one of the cases, was cytogenetically found to be associated with an inversion of the ALK gene. While OMHs were positive for smooth muscle actin (SMA), desmin, WT1, podoplanin, and cytokeratins (CAM5.2 and AE1-3), IMT were consistently positive only for SMA (10 cases). ALK-1 displayed cytoplasmic staining in IMT and characteristic paranuclear dot-like staining in OMH.

Primary malignant lymphoma arising in postmastectomy lymphedema. Another facet of the Stewart-Treves syndrome.

In rare cases, primary malignant lymphomas may arise in the soft tissues. Only one previous case has arisen in the context of chronic lymphedema. Because of the clinical appearance of such lesions, which resemble violaceous nodular or plaquelike tumors, they may be confused clinically with lymphedema-associated angiosarcomas occurring after radical mastectomy (Stewart-Treves syndrome). Furthermore, the histologic appearance of some lymphomas and angiosarcomas may also be similar. We studied two women with primary postmastectomy lymphedema-related malignant lymphoma in the soft tissues of the upper arm. These tumors arose 11 and 30 years, respectively, after radical removal of ductal mammary carcinomas. Histologically, one neoplasm mimicked metastatic carcinoma or epithelioid angiosarcoma; whereas the other was initially confused with a variety of pathologic entities, including vasculitis, epithelioid hemangioma, and malignant fibrous histiocytoma. The lymphoid nature of both lesions was confirmed by immunoreactivity for leukocyte common antigen in addition to the B-lymphocyte marker, L26. Conversely, vascular and epithelial determinants were absent. One patient's disease pursued an indolent course; she died of unknown causes but with no evidence of lymphoma at last follow-up. The second patient is currently in remission on chemotherapy. Awareness of the existence of lymphedema-related malignant lymphoma and familiarity with methods used for its distinction from epithelioid vascular sarcomas should prevent unnecessary surgery.

Melanotic neuroectodermal tumor of infancy. A reexamination of a histogenetic problem based on immunohistochemical, flow cytometric, and ultrastructural study of 10 cases.

Ten cases of melanotic neuroectodermal tumor of infancy (MNTI) were studied. There were nine males and one female ranging in age from 2 weeks to 10 months; one patient was 8 years old. Sites of origin were the maxilla (five), epididymis (two), mandible (one), skull (one), and soft tissues of the cheek (one). Six tumors recurred from 1 to 18 months after diagnosis. One patient had widespread dissemination. Electron microscopic study of four cases showed cells with melanosomes at various stages of maturation, and cells with neuroblastic features, including neurosecretory granules and cytoplasmic processes. Nine cases of MNTI were studied immunohistochemically. Small neuroblastic cells and large cells in all cases were reactive for neuron-specific enolase (NSE), synaptophysin, HMB45, and dopamine-beta-hydroxylase, large cells in all cases and few small cells were reactive for cytokeratin (CK) and vimentin (VIM). Epithelial membrane antigen was observed in large cells in three cases, four cases expressed Leu 7 antigen, three were focally positive for glial fibrillary acidic protein, one for desmin, and one for chromogranin. All cases were nonreactive for retinol-binding protein, neurofilaments, alpha-fetoprotein, S-100 protein, and carcinoembryonic antigen. Five normal adult retinas were studied similarly; the pigmented epithelium of the retina was reactive for CK, VIM, HMB45, NSE, and S-100. DNA study, performed in eight tumors, revealed aneuploidy in two (DNA index = 1.7 and 1.8); these cases recurred within 1 month. No differences were observed according to site or behavior. MNTI is a primitive neuroectodermal tumor with polyphenotypic expression of neural and epithelial markers, melanin production, occasional glial, and rhabdomyoblastic differentiation, and no photoreceptor differentiation. It probably represents a dysembryogenetic neoplasm that recapitulates the retina at 5 weeks of gestation.

Evidence of involvement of the PLAG1 gene in lipoblastomas.

Previous cytogenetic studies have demonstrated that the majority of lipoblastomas show rearrangements, in particular translocations and insertions, with breakpoints in 8q11-13. Here we present evidence for involvement of the developmentally regulated zink finger gene PLAG1 in these rearrangements. Northern blot and RT-PCR analyses revealed overexpression of PLAG1 in two lipoblastomas. Using immunohistochemistry, expression of the PLAG1 protein was also demonstrated in tissue sections from two lipoblastomas, one of which had a t(3;8)(q13.1;q12) translocation and the other a t(1;6)(q42;p22) translocation. Since no aberrant PLAG1 transcripts could be detected, it is likely that the gene may be activated by promoter swapping/substitution or alternatively by an as yet unknown mechanism. Our findings indicate that PLAG1 activation is a recurrent event in lipoblastomas and that PLAG1 is likely to be the target gene on chromosome 8 in these tumors.

Soft-tissue and meningeal hemangiopericytomas: an immunohistochemical and ultrastructural study.

The debate on the nosologic position of hemangiopericytomas of the meninges has been based mainly on light microscopic and ultrastructural considerations; recent immunohistochemical studies have yielded controversial results. We have used a panel of antibodies to vimentin, desmin, actin, S100 protein, epithelial membrane antigen, cytokeratins, Leu-7, factor VIII-related antigen and type IV collagen to compare the immunophenotype of 10 soft-tissue and seven meningeal hemangiopericytomas. The immunophenotypic profile of these tumors is identical, and differs from that of meningiomas in that epithelial membrane antigen and cytokeratin are not present. The vascular pattern occurring in some meningiomas can simulate true hemangiopericytomas of the meninges. Immunohistochemical studies should allow their distinction in each instance. Meningeal and soft-tissue hemangiopericytomas display similar ultrastructural features.

Intestinal ganglioneuromatosis: mucosal and transmural types. A clinicopathologic and immunohistochemical study of six cases.

Six cases of intestinal ganglioneuromatosis (GN) included in this study reveal the occurrence of two morphologic patterns. Transmural GN was characterized by neural hyperplasia in all layers of the bowel wall with predominant involvement of the myenteric plexus. It was found in three patients affected by multiple endocrine neoplasia IIb. Mucosal GN, having predominant involvement of the mucosa without concomitant hyperplasia of the myenteric plexus, was associated with von Recklinghausen's disease, adenocarcinoma of the colon, and multiple adenomas with megacolon in one case each. Clinicopathologic correlations and review of the literature suggest that mucosal GN might represent a distinct entity with a lower morbidity rate than the transmural variant. Immunohistochemical stains reveal considerable heterogeneity. S-100 protein, neuron-specific enolase, and synapto-physin immunostaining followed the distribution of the nervous hyperplasia in the different intestinal layers as identified morphologically and allowed precise determination of the proliferating cells. Increased reactivity for vasoactive intestinal polypeptide, opioid peptides leu-enkephalin and met-enkephalin, and substance P was present in all cases with transmural involvement; mucosal GN showed normal reactivity for opioid peptides and focal increased staining for substance P (one case) and vasoactive intestinal polypeptide (two cases) in the lamina propria. Mild increased immunoreactivity for tyrosine hydroxylase was present in the myenteric plexus of four out of four cases. Histochemical determination of acetylcholinesterase, performed in one case of transmural type, demonstrated hyperplasia of parasympathetic fibers and neurons. Electron microscopic study of another case suggested the presence of several neurotransmitters. These results indicate that the physiopathology of GN is related to a complex hyperplasia of several peptidergic, cholinergic, and probably adrenergic nerve fibers instead of a selective overgrowth of one type of nerve fiber.

Leiomyomatosis with vascular invasion. A unified pathogenesis regarding leiomyoma with vascular microinvasion, benign metastasizing leiomyoma and intravenous leiomyomatosis.

Three uterine leiomyomas with vascular invasion (LWVI), two of which were associated with pulmonary leiomyomatous nodules, and a case of intravenous leiomyomatosis (IVL) invading the vena cava and extending to the right atrium, are described. Despite their histological benignity, these lesions have a strong tendency to metastasize and are closely related to the so-called benign metastasizing leiomyoma (BML). From a clinical point of view, the pulmonary nodules of LWVI are stable or slowly-growing. The IVL was a "worm-like" tumour that presented as a cardiac mass. On the basis of their histological and immunohistological features, a unified histogenetic view of LWVI, IVL and BML of the uterus is proposed. LWVI and BML may be the same pathological entity and microscopic vascular invasion may represent the metastatic mechanism of BML. Alternatively, LWVI may be the initial stage of IVL. In rare instances, IVL may be associated with distant parenchymal (pulmonary) metastases. LWVI seems to be the precursor of both BML and IVL.

Cellular and Molecular Characterization of Two Cases of Castleman's Disease, Plasma Cell Variant.

We report the cellular and molecular characterization of two cases of Castleman's disease, plasma cell variant, that differed in their clinical presentation and course. Patient 1 had Castleman's disease in association with Kaposis's sarcoma unrelated to human immunodeficiency virus (HIV) infection and died while he was receiving an aggressive chemotherapeutic regimen for Kaposi's sarcoma. Patient 2 had an isolated retroperitoneal lymphoid mass with an adjacent enlarged limph nodes and his symptoms disappeared completely following the surgical removal of both. Pathologic and immunohistochemical analyses in both cases, revealed that there was a massive infiltration of polyclonal plasma cells in the interfollicular areas of the lymph nodes. Immunoglobulin gene rearrangement studies confirmed the polyclonal nature of B-lineage cells in the involved lymph nodes. Southern blot experiments failed to demonstrate the presence of EBV genome copies in the same lymph nodes. These paradigmatic cases lend further support to the notion that Castleman's disease is an extremely heterogeneous entity.

Bronchiolitis obliterans organizing pneumonia (BOOP) in a child with mild-to-moderate asthma: evidence of mast cell and eosinophil recruitment in lung specimens.

Bronchiolitis obliterans with organizing pneumonia (BOOP) is rarely described in children and little is known about its pathogenesis. This paper reports on an 11-year-old patient suffering from mild-to-moderate asthma. He presented with a retrocardiac density at chest computed tomography scan that was slow to resolve and failed to respond to antibiotic therapy. Open lung biopsy revealed a histological picture with buds of granulation tissue in respiratory bronchioles and alveolar ducts, with organized extensions into the alveoli. The use of monoclonal antibodies on biopsy specimens demonstrated the presence of an inflammatory process affecting not only the thickened alveolar walls, but also the remaining lung parenchyma, the pulmonary arteries, and the bronchioles. The inflammatory infiltrate consisted mainly of mast cells and eosinophils. The clinical condition improved with steroid therapy. To the best of the authors' knowledge, this is the first report of BOOP in an asthmatic child with recruitment of mast cells and eosinophils documented by using monoclonal antibodies.

Lung volume reduction surgery in lieu of pneumonectomy in an infant with severe unilateral pulmonary interstitial emphysema.

A male infant with a prenatal diagnosis (at 20 weeks' gestation) of cystic adenomatoid malformation was delivered after 38 weeks' gestation (birth weight, 3 kg) and admitted to the neonatal intensive care unit. During the first few days of life, he developed mild respiratory distress; a chest radiograph and computed tomography scan showed multiple cystic areas in the left lower lobe with hyperinflation and herniation of the upper lobe across the midline. At 3 weeks of age, a left lower lobectomy was performed for presumed cystic malformation. To our surprise the pathology reports revealed pulmonary interstitial emphysema. The postoperative chest radiograph was unchanged, and mechanical ventilation was necessary and required progressively increasing ventilatory settings to provide adequate support. High-frequency oscillatory ventilation and selective right bronchus intubation failed to improve lung function. After 3 weeks, a left thoracotomy was repeated and lung volume reduction was performed with removal of 50' of the peripheral hyperinflated parenchyma. Postoperative recovery was rapid; the child was weaned from the ventilator after 3 days and discharged after 3 weeks. Follow-up chest X-rays showed a normally expanded right lung with mediastinal structures back to midline and a small left lung. Favorable results persisted at 3 years of follow-up. This first and successful experience with lung volume reduction in a neonate suggests that infants who need removal of a large portion of lung parenchyma to achieve adequate ventilation and gas exchange, lung volume reduction surgery should be considered as an alternative to pneumonectomy.

DNA flow cytometry of endoscopically examined colorectal adenocarcinomas.

The purpose of the study was to evaluate the correlation of DNA-ploidy of colorectal adenocarcinomas (adk) with histological and clinical parameters including the survival of the patients. Multiple biopsies from 95 adk were taken during colonoscopy prior to surgery. The samples were used to obtain nuclei suspensions for specific staining of DNA content and high resolution flow cytometry. DNA-aneuploidy, i.e. the presence of more than one G0/G1 peak, was detected in 67/95 cases (71%). The individual-specific control mucosa was DNA-diploid in all cases. The mean fraction of S-phase cells was 7.2% in control mucosa and 13.6% in adk. DNA-ploidy did neither correlate with Dukes' stage nor with differentiation degree. Among the patients studied for the correlation of DNA ploidy with survival for a period extending to 30 months (n = 51), the DNA aneuploid group was estimated to be about 5 times as risky as the DNA diploid group with respect to the odds of dying. We conclude that DNA flow cytometry of colorectal adk may predict clinical outcome and be helpful in addition to histopathology.

Lack of prognostic value of histopathologic parameters in Hodgkin's disease, nodular sclerosis type. A study of 123 patients with limited stage disease who had undergone laparotomy and were treated with radiation therapy.

The value of histopathologic parameters in predicting the long-term overall survival probabilities was studied in a series of 123 patients with pathologic stage IA, IB, IIA, IIB, or IIIA Hodgkin's disease, nodular sclerosis type who were treated with curative radiation therapy. The parameters that were studied included the relative proportion of atypical vs reactive cells, amount of eosinophils, presence of necrosis, degree of mitotic activity, intensity of different types of mesenchymal reactions, classification in three subtypes (ie, lymphocyte predominance, mixed cellularity, and lymphocyte depletion) or in two grades (ie, grades 1 and 2), and identification of the syncytial variant. For each parameter, the association with clinical risk factors was also analyzed. The results of this study show that there are no pathologic features that carry a significant predictive value of the overall survival.

Undifferentiated carcinoma of the gallbladder. Report of a case with immunohistochemical findings.

One case of undifferentiated carcinoma of the gallbladder was studied using an extensive immunohistochemical panel of antibodies. The biphasic differentiation of the tumor was highlighted by different immunoreactivity to antibodies against cytokeratins, vimentin, epithelial membrane antigen, and carcinoembryonic antigen of the adenocarcinomatous and mesenchymallike components, although the latter showed a faint positivity for CAM5.2 antibody, probably indicating an epithelial origin. Furthermore, the higher levels of expression of p53 protein and the faster growth rate in the pseudosarcomatous component suggest its more malignant phenotype. The relationship with "true" carcinosarcomas of the gallbladder and the histogenetic theories concerning these tumors are also discussed.

Clear cell tumors of the somatic soft tissues.

The prototypic soft tissue tumor showing "clear" cytoplasmic features is the so-called clear cell sarcoma or malignant melanoma of soft parts, a tumor characterized by immunophenotypic and ultrastructural melanogenic differentiation and specific cytogenetic and molecular abnormalities, ie, t(12;22)(q13;q12) translocation and Ewing's sarcoma oncogene/activating transcription factor 1 rearrangement. A number of other malignant soft tissue tumors occasionally show cytoplasmic clarity, including epithelioid leiomyosarcomas, malignant peripheral nerve sheath tumors, and sclerosing fibrosarcomas, as well as metastatic carcinomas and malignant melanomas. These tumors are discussed in relation to their differential diagnosis with clear cell sarcomas.