Inv(11)(p13p15) and myf-3(MyoD1) in a malignant extrarenal rhabdoid tumor of a premature newborn

Ultrasound Presentation of a Disseminated Fetal and Neonatal Rhabdoid Tumor

This is a case report of a disseminated fetal rhabdoid tumor discovered at 32 weeks of gestation in a 29-year-old woman on immunosuppressive therapy. The mother consulted for a decrease in fetal movement. Fetal ultrasound showed signs of a disseminated tumor affecting the left armpit, liver, spleen, and limbs. A caesarian section was performed because of signs of fetal distress. Immunohistochemical analysis of a fetal biopsy showed deletion of the SMARCB1 gene. Pathological analysis of the placenta showed a rhabdoid tumor invading both fetal and maternal compartments. The mother underwent a whole-body MRI, and no metastasis was found. To the best of our knowledge, this is the first report of a disseminated rhabdoid tumor invading both fetal and maternal compartments.

Malignant Rhabdoid Tumor with Cervical Vertebra Involvement in a Teenage Child: Case Report and Review of the Literature

Malignant rhabdoid tumor (MRT) is a highly malignant and aggressive tumor associated with the kidney that is mainly seen in children under 5 years old, resulting in a rapid fatal outcome. MRT invasion of the cervical vertebra is an extremely rare form of this malignancy. This study presents a case of MRT involving the C4 vertebra and its appendix. A 13-year-old girl was found to have vague neck pain and a mass in the left neck area of the mid-cervical spine. Percutaneous needle biopsy was performed and the histological and immunohistochemical analysis pointed towards a rhabdoid tumor. Chemotherapy and radiotherapy were performed, but the tumor mass progressively enlarged. Tumorectomy was conducted followed by another 6 courses of chemotherapy and (125)I radioactive seed implantation. Unfortunately, the C4 vertebra and its appendix were found to be abnormal 3 months after the end of therapy. The patient received an additional tumorectomy, internal fixation with C4 reconstruction by a combined anterior and posterior approach, and 6 courses of consolidation chemotherapy. She is still alive 40 months since the initial diagnosis and remains asymptomatic 31 months after the surgery.

Surgery and actinomycin improve survival in malignant rhabdoid tumor

Purpose. Malignant rhabdoid tumor (MRT) is an uncommon tumor that rarely occurs outside of renal and central nervous system (CNS) sites. Data from the literature were compiled to determine prognostic factors, including both demographic and treatment variables of malignant rhabdoid tumor, focusing on those tumors arising in extra-renal, extra-CNS (ER/EC MRT) sites. Patients and Methods. A systematic review and meta-analysis was performed by extracting demographic, treatment, and survival follow up on 167 cases of primary ER/EC MRT identified in the literature. Results. No survival differences were observed between those treated with or without radiation, or with or without chemotherapy. A Cox regression of overall survival revealed several independent prognostic factors. Surgical excision had a 74% (P = 0.0003) improvement in survival. Actinomycin had a 73% (P = 0.093) improvement in survival. Older age was associated with improved survival. The four-year survival, by Kaplan-Meier estimates, comparing patients less than two years old versus older than two at diagnosis was 11% versus 35%, respectively (P = 0.0001, Log-Rank). Conclusion. ER/EC MRT is a rare, soft-tissue tumor with a poor prognosis most commonly occurring in children. Surgical resection, treatment with actinomycin, and older age at diagnosis are all associated with improved survival.

Fetal and neonatal rhabdoid tumor

PURPOSE

Few studies have focused on the behavior of rhabdoid tumor (RT) in the fetus and neonate. The purpose of this review is to show that perinatal RTs are associated with unusual findings and a poor prognosis.

METHODS

The author conducted a 40-year systematic review of the literature. Clinical presentation, pathology, management, and outcome of 72 fetuses and neonates with RTs are discussed.

RESULTS

Seventy-two fetuses and neonates presented with RTs detected prenatally (n = 12) and during the neonatal period (n = 60). The review consisted of 3 main groups: extrarenal noncentral nervous system (CNS) RT, renal RT, and CNS RT. There were some group differences in survival: extrarenal non-CNS RT (3/33 or 9.1%), renal RT (2/27 or 7.4%), and CNS RT (2/12 or 16.7%). Metastatic RT was present at diagnosis in more than half the patients (41/72 or 57%) who had a survival of 2.3%. The overall survival was 9.7%. For statistical results, there was no significant difference in survival among the 3 groups by type of tumor (P = .692). chi(2) analysis for survival with and without metastases was not valid due to small sample size.

CONCLUSIONS

The review shows that extrarenal RT was more common than either renal RT or CNS RT groups that is different than that observed in older individuals. Concomitant brain tumors were found in almost a third of fetuses and neonates. The CNS involvement occurred more often in patients with renal RT than in those with extrarenal RT. Metastatic disease at diagnosis was noted in more than half of the patients. Higher stage and presence of a CNS tumor were significant determinants in survival.

Undifferentiated Perivascular Cells in Myxoid Mesenchymal Tumors: An Ultrastructural Study

The current WHO classification of soft tissue tumors is based on the lineage of differentiation of the proliferating cells. Since mature mesenchymal cells have a broad phenotypic plasticity it has been considered unnecessary to recur to a hypothetical stem cell to explain the origin of these neoplasms. In spite of this assumption, the target cell of the oncogenic mutations in mesenchymal tumors is still a controversial item. Myxoid mesenchymal tumors constitute a heterogeneous group of neoplasms sharing in an ample mucinous matrix that separates neoplastic cells and facilitates their single submicroscopic study under electron microscopy examination. The authors have studied, by electron microscopy, 74 myxoid mesenchymal tumors, including a large variety of nosologic entities, to assess their madurational gradient. In 43 of 74 cases, a common element has been found: medium-sized cells, with high nucleo-cytoplasmic ratio, lacking lineage specific features, which were arranged around the capillary vessels. In some cases, the authors were able to demonstrate gradual differentiation in these cells, as they moved away from the vessels. These features support the hypothesis that at least some mesenchymal tumors originate from perivascular undifferentiated cells. In addition, the findings might contribute to define both topographic and morphologic characteristics of adult stem mesenchymal cells.

The tumour suppressor hSNF5/INI1 controls the differentiation potential of malignant rhabdoid cells

Malignant rhabdoid tumours (MRT) are highly aggressive cancers of early childhood that arise in different organs or tissues. The unifying criterion for these tumours is the presence of inactivating mutations of the hSNF5/INI1 tumour suppressor gene which encodes a core subunit of the chromatin remodelling SWI/SNF complex. Using a variety of markers we analysed the phenotypic traits of MON and DEV cell lines derived respectively from an undifferentiated abdominal MRT and from a brain MRT. DEV cells express spontaneously a wide range of neural and glial markers. It can be induced to differentiate into the neural lineage following hSNF5/INI1 expression with appearance of neurite processes, strong increase of neural markers and decrease of glial markers. A less pronounced neural differentiation is also observed with MON cells, which possess more primitive polyphenotypic features with positivity for markers from the three embryonic layers. Finally, we show that the neural differentiation of rat PC12 cells in the presence of nerve growth factor (NGF) is strongly impaired when hSNF5/INI1 expression is inhibited by RNA interference. Altogether these results indicate that hSNF5/INI1 is an essential subunit for SWI/SNF-dependant induction of neural differentiation programs. Further experiments should enable documentation of whether it provides instructive or permissive signals for differentiation.

Chromosome mechanisms and INI1 inactivation in human and mouse rhabdoid tumors

The human rhabdoid tumorigenesis orchestrated by INI1 inactivation is associated with specific rearrangements of chromosome 22 that correlate with preferential anatomic tumor locations. A literature review revealed significant correlations between an apparently normal karyotype and kidney tumors, monosomy 22 and cerebral tumors, and chromosome 22 translocations and tumors at other anatomic sites. In the mouse rhabdoid tumor model, specifically in the four tumors that we tested for loss of heterozygosity, neither partial deletion nor monosomy of chromosome 10 could be detected. In contrast to the human data, the only chromosome mechanism involved in the 18 mouse tumors studied appears to be a mitotic recombination or a nondisjunction-duplication. Additionally, and despite mouse tumor incidence across a variety of sites, no rhabdoid tumor could be observed in the mouse kidney. These data suggest that the chromosome mechanisms for INI1 inactivation and the selective cell survival pressure differ in human and mouse.

Paratesticular congenital malignant rhabdoid tumor diagnosed by fine-needle aspiration cytology. a case report

We report the FNA features of a congenital malignant extrarenal rhabdoid tumor (MERT) located in the right paratesticular area of a newborn full-term boy (39 wk gestation), with disseminated metastases in the liver and right parietal region. The diagnosis was suggested two days after birth by fine-needle aspiration biopsy (FNAB) of the parietal mass, which demonstrated an atypical large cell proliferation with vesicular nuclei, prominent nucleoli, and abundant cytoplasm exhibiting paranuclear dense inclusions. The diagnosis was confirmed by histopathologic and immunohistochemical examination of the primary paratesticular tumor. To the best of our knowledge, this is the third MERT reported in the paratesticular region, one of the few congenital extrarenal non-central nervous system cases, and the third congenital case (renal or extrarenal) primarily diagnosed by FNAB. We emphasize the characteristic cytologic features of a congenital rhabdoid tumor, which must be known by pathologists because of the clinical and prognostic implications. Diagn. Cytopathol. 2004;30:46-50.

Expression of pericyte, mesangium and muscle markers in malignant rhabdoid tumor cell lines: differentiation-induction using 5-azacytidine

Malignant rhabdoid tumor (MRT) has been considered to have multiphenotypic diversity characteristics. Some MRTs exhibit a neural phenotype. However, it is still unclear whether MRT cells can display a skeletal muscle, smooth muscle or smooth muscle-like cell phenotype, like those of pericytes and mesangial cells. To determine if MRTs exhibit skeletal muscle cell or smooth muscle-like cell phenotypes, six MRT cell lines (TM87-16, STM91-01, TTC549, TTC642, YAM-RTK1 and TTC1240) were examined for markers of skeletal muscle (MyoD, myogenin, myf-5, myf-6, acetylcholine receptor-alpha, -beta and -gamma), smooth muscle (alpha-smooth muscle actin, SM-1 and SM22), and smooth muscle-like cells, such as pericytes (angiopoietin-1 and -2) and mesangial cells (megsin), using conventional RT-PCR, semi-quantitative PCR, western blotting and immunocytochemistry before and after differentiation-induction with 5-azacytidine. alpha-Smooth muscle actin and SM22 were detected in all six MRT cell lines, while MyoD and myf-5, crucial markers for skeletal myogenic determination, were not. The TM87-16 cell line expressed SM-1 and angiopoietin-1. TTC1240 also expressed angiopoietin-1. Interestingly, STM91-01 expressed megsin, a novel marker for mesangial cells, in addition to angiopoietin-1. Our results indicated that some MRTs exhibited smooth muscle and/or smooth muscle-like cell phenotypes and some renal MRTs might be of mesangial origin. Recently, smooth muscle and also smooth muscle-like cells have been considered to be of neuroectodermal origin. MRT can thus considered to belong to the category of primitive neuroectodermal tumors (PNETs) in the broad sense.

Multiple complementary transcripts of pCMa1, a novel gene located at chromosome 11p15.1-2, and melanocytic cell transformation

The cDNA clone pCMa1 (0.45 kb) is one of the 12 novel cDNAs, previously identified when comparing RNA expression profiles of melanocytes, naevus cells, and non-metastatic melanoma cells. This clone did not reveal a unique long open reading frame. The pCMa1 gene localized to the distal, telomere proximal region on the short arm of chromosome 11.p15.1-2. Northern blot analyses with single-stranded cRNA probes revealed the presence of various complementary pCMa1 transcripts of different lengths, which are not enriched in the poly(A)(+) RNA fraction. The arbitrarily defined plus strand (used as a probe) mainly hybridized to 0.45 kb and 4.0 kb minus transcripts in total RNA samples, and the minus strand (used as a probe) hybridized to a major plus transcript of 4.0 kb. By RNA in situ hybridization, the highest levels of the plus transcripts were observed in melanocytic naevi (12/12), particularly in congenital naevi, whereas normal skin melanocytes (12/12) were negative. pCMa1 plus transcripts were detected in naevus cell nests (100%) near the dermo-epidermal junction. Expression, however, diminished to some extent in the deeper parts of the melanocytic naevi. Although most of the cutaneous primary melanoma lesions (11/15) showed detectable, but variable levels of plus transcripts of pCMa1 in the papillary to reticular dermis, not more than 10% of the melanoma cells were positive. The majority of melanoma metastases (6/7) were negative, while the positive lesion originated from a patient with a positive primary melanoma. Furthermore, plus transcripts were present in the nuclei of non-metastatic melanoma cells in culture, whereas metastatic cells showed elevated expression both in the nucleus and in the cytoplasm. Briefly, the data show transient up-regulation of pCMa1 in neoplastic progression of melanocytic cells, with peak levels occurring during naevus stages, and suggest that pCMa1 is a molecular marker in melanocytes for the early changes from the proliferating phenotype to malignant transformation.

Two case reports of rare fetal tumors: an indication for surface rendering?

Fetal tumors are rare and can be difficult to diagnose in utero. This report describes one case of an extrarenal rhabdoid tumor and one case of a giant congenital melanocytic nevus. Both presented with moderate polyhydramnios and were prenatally detected at 31 weeks of gestation with two-dimensional ultrasound. The application of the surface mode of three-dimensional ultrasound improved the visualization of these tumors especially for the parents and the multidisciplinary team. Three-dimensional sonography proved to be a valuable addition to the prenatal armamentarium for the evaluation of these fetal tumors although it is not mandatory for their assessment and clinical management.