Mutation analysis of human cytokeratin 8 gene in malignant rhabdoid tumor: a possible association with intracytoplasmic inclusion body formation

Multinucleate parietal cells and cytoplasmic inclusion bodies in the gastric epithelium of callitrichids

Inclusion bodies (IBs) and multinucleate cells can be associated with viral infections; however, IBs and multinucleate cells have been described in normal tissue and with non-viral disease processes in multiple species. We examined fundic stomach from 50 callitrichids histologically for bi- and multinucleate parietal cells and cytoplasmic IBs in gastric epithelial cells. Callitrichids represented included 6 genera: Saguinus (4 spp.), Leontopithecus (1 sp.), Mico (3 spp.), Cebuella (1 sp.), Callithrix (1 sp.), Callimico (1 sp.), and 13 unspecified marmosets. Gastric epithelial IBs were present in 46 of 47 (98%) of the callitrichids from which the stomach was sufficiently well preserved to identify IBs. Cytoplasmic IBs were identified in gastric surface pit epithelial cells (43 of 44, 98%), mucous neck cells (43 of 44, 98%), parietal cells (43 of 44, 98%), and chief cells (43 of 44, 98%). The IBs were eosinophilic, ovoid, round, elongate, or variably indented, sometimes slightly refractile, and 1-6 × 1-13 µm. IBs were sometimes perinuclear and molded around the nucleus. Electron microscopy of the gastric epithelium of one marmoset indicated that IBs were composed of intermediate filaments. The IBs did not stain with immunohistochemical markers for cytokeratin AE1/AE3 or vimentin. Binucleate parietal cells were found in 49 of 50 (98%) callitrichids, and multinucleate parietal cells were observed in 40 of 49 (82%) callitrichids. Gastric epithelial cytoplasmic IBs and bi- and multinucleate parietal cells are likely a normal finding in callitrichids, and, to our knowledge, have not been reported previously.

Malignant rhabdoid tumor of the floor of mouth: first reported case in the oral cavity of an adult

Malignant rhabdoid tumors (MRTs) are exceedingly rare lesions. To our knowledge, only 2 cases have been reported in the oral cavity, with both examples occurring in infants. The current case is the third reported case of MRT of the oral cavity and the first reported case to occur in an adult at this location. The following report describes the clinical, histologic and immunohistochemical features of this tumor.

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.

Hepatocyte-derived cultured cells with unusual cytoplasmic keratin-rich spheroid bodies

Cytoplasmic inclusions are found in a variety of diseases that are characteristic morphological features of several hepatic, muscular and neurodegenerative disorders. They display a predominantly filamentous ultrastructure that is also observed in malignant rhabdoid tumor (MRT). A cellular clone containing an intracytoplasmic body was isolated from hepatocyte cell culture, and in the present study we examined whether this body might be related or not to Mallory-Denk body (MDB), a well characterized intracytoplasmic inclusion, or whether this cellular clone was constituted by malignant rhabdoid tumor cells. The intracytoplasmic body was observed in electron microscopy (EM), confocal immunofluorescence microscopy and several proteins involved in the formation of its structure were identified. Using light microscopy, a spheroid body (SB) described as a single regular-shaped cytoplasmic body was observed in cells. During cytokinesis, the SB was disassembled and reassembled in a way to reconstitute a unique SB in each progeny cell. EM examination revealed that the SB was not surrounded by a limiting membrane. However, cytoplasmic filaments were concentrated in a whorled array. These proteins were identified as keratins 8 and 18 (K8/K18), which formed the central core of the SB surrounded by a vimentin cage-like structure. This structure was not related to Mallory-Denk body or aggresome since no aggregated proteins were located in SB. Moreover, the structure of SB was not due to mutations in the primary sequence of K8/K18 and vimentin since no difference was observed in the mRNA sequence of their genes, isolated from Huh-7 and Huh-7w7.3 cells. These data suggested that cellular factor(s) could be responsible for the SB formation process. Aggregates of K18 were relocated in the SB when a mutant of K18 inducing disruption of K8/K18 IF network was expressed in the cellular clone. Furthermore, the INI1 protein, a remodeling-chromatin factor deficient in rhabdoid cells, which contain a spheroid perinuclear inclusion body, was found in our cellular clone. In conclusion, our data suggest that Huh-7w7.3 cells constitute an excellent model for determining the cellular factor(s) involved in the process of spheroid perinuclear body formation.

Primary rhabdoid cancer of the ileum: a case report and review of the literature

Since the first publication of a rhabdoid cancer, described as an infrequent variant of Wilms' tumor, several cases of extrarenal rhabdoid tumor have been reported in the literature. Here, we report on a primary rhabdoid cancer of the small intestine, and give a review of the data available in the literature. An 81-year-old male patient was admitted to the Department of Internal Medicine with subileus and bloody stools. While gastroscopy and colonoscopy failed to identify a neoplastic disease, abdominal US and CT raised the suspicion of a malignancy involving the descending colon. Ileus-mandated laparotomy disclosed an obstructive tumor of the ileum. This segment was resected, followed by several relapses, and the patient died after a 7-month-period of non-relenting deterioration. Histological work-up of the numerous biopsies disclosed a cellular, solid, necrotic, hemorrhagic, and invasive tumor. The cancer cells were round-to-polygonal, and scattered bizarre pleomorphic cells with prominent nucleoli were common. The overall appearance of the neoplasm was highly similar in every specimen. The immunohistochemical phenotype of the malignant cells indicated rhabdoid characteristics. A thorough search of the literature revealed additional 22 cases of primary rhabdoid GI cancers. This report aims to call the pathologist's attention to the differential diagnostic importance of this entity.

Improved survival in patients with breast rhabdoid tumors with multi-agent adjuvant chemotherapy combined with irradiation

PURPOSE

Malignant rhabdoid tumors (MRT) have poor prognoses. Breast MRT is extremely rare; only three cases have been documented, with a mean prognosis of 7 months. Multi-agent chemotherapy with mastectomy and irradiation, as used in this case, may extend survival in breast MRT.

PATIENT AND METHODS

A 68-year-old woman who underwent a standard mastectomy was diagnosed with breast MRT. Postoperatively she received six cycles of cyclophosphamide/methotrexate/5-fluorouracil followed by oral administration of doxifluridine and anastrozole, after which no metastasis was detected. About 8 months postoperative, magnetic resonance imaging revealed cervical bone metastasis, and local irradiation and nine doses of "basic chemotherapy" consisting of biweekly paclitaxel and anastrozole were administered. About 4 months later, multiple lung metastases were revealed, and four doses of "basic chemotherapy" with added pirarubicin hydrochloride were administered. Four months after that, multiple large liver metastases were discovered, and five doses of "basic chemotherapy" with added carboplatin were administered.

RESULTS

The 19-month survival period of our case was almost three times that of reported breast MRT patients.

CONCLUSION

Multi-agent chemotherapy combined with irradiation may be associated with the relatively long survival of the present case.

Clone-specific expression, transcriptional regulation, and action of interleukin-6 in human colon carcinoma cells

Background

Many cancer cells produce interleukin-6 (IL-6), a cytokine that plays a role in growth stimulation, metastasis, and angiogenesis of secondary tumours in a variety of malignancies, including colorectal cancer. Effectiveness of IL-6 in this respect may depend on the quantity of basal and inducible IL-6 expressed as the tumour progresses through stages of malignancy. We therefore have evaluated the effect of IL-6 modulators, i.e. IL-1β, prostaglandin E₂, 17β-estradiol, and 1,25-dihydroxyvitamin D₃, on expression and synthesis of the cytokine at different stages of tumour progression.

Methods

We utilized cultures of the human colon carcinoma cell clones Caco-2/AQ, COGA-1A and COGA-13, all of which expressed differentiation and proliferation markers typical of distinct stages of tumour progression. IL-6 mRNA and protein levels were assayed by RT-PCR and ELISA, respectively. DNA sequencing was utilized to detect polymorphisms in the IL-6 gene promoter.

Results

IL-6 mRNA and protein concentrations were low in well and moderately differentiated Caco-2/AQ and COGA-1A cells, but were high in poorly differentiated COGA-13 cells. Addition of IL-1β (5 ng/ml) to a COGA-13 culture raised IL-6 production approximately thousandfold via a prostaglandin-independent mechanism. Addition of 17β-estradiol (10^-7 M) reduced basal IL-6 production by one-third, but IL-1β-inducible IL-6 was unaffected. Search for polymorphisms in the IL-6 promoter revealed the presence of a single haplotype, i.e., -597A/-572G/-174C, in COGA-13 cells, which is associated with a high degree of transcriptional activity of the IL-6 gene. IL-6 blocked differentiation only in Caco-2/AQ cells and stimulated mitosis through up-regulation of c-myc proto-oncogene expression. These effects were inhibited by 10^-8 M 1,25-dihydroxyvitamin D₃.

Conclusion

In human colon carcinoma cells derived from well and moderately differentiated tumours, IL-6 expression is low and only marginally affected, if at all, by PGE₂, 1,25-dihydroxyvitamin D₃, and 17β-estradiol. However, IL-6 is highly abundant in undifferentiated tumour cells and is effectively stimulated by IL-1β. In case of overexpression of an IL-6 gene variant with extreme sensitivity to IL-1β, massive release of the cytokine from undifferentiated tumour cells may accelerate progression towards malignancy by paracrine action on more differentiated tumour cells with a still functioning proliferative IL-6 signalling pathway.

Successful salvage and long-term survival after recurrent malignant rhabdoid tumor

Purpose. The objective of this study is to report a case of a rare, highly lethal tumor, extrarenal malignant rhabdoid tumor (EMRT) in a 43-year-old man who initially presented with a local recurrence and is now continuously disease free 14 years after aggressive surgical treatment. The case and literature are discussed.

Highly aggressive behavior of malignant rhabdoid tumor: a special reference to SMARCB1/INI1 gene alterations using molecular genetic analysis including quantitative real-time PCR

PURPOSE

SMARCB1/INI1, which negatively regulates cell cycle progression from G0/G1 into the S-phase via the p16INK4a-RB-E2F pathway, has been reported to be inactivated homozygously by deletion and/or mutations in malignant rhabdoid tumor (MRT). In the current study, we investigated the alteration of the SMARCB1/INI1 gene using simple methods, and its gene product at the protein level. Moreover, we investigated the status of hyperphosphorylation in RB protein, known as a key cell cycle molecule.

METHODS

Three cell lines and 11 formalin-fixed, paraffin-embedded specimens of MRT were investigated. SMARCB1/INI1 gene alteration was analyzed with simple methods as a quantitative real-time PCR and direct sequencing method. Furthermore, SMARCB1/INI1 and RB protein were immunohistochemically evaluated.

RESULTS

In 12 of 14 cases, we detected genetic alterations comprised of nine (including three cell lines) homozygous deletions and three mutations, which can induce abnormal expression of gene products. At the protein level, SMARCB1/INI1 immunohistochemical expressions were not detected in any cases. Twelve out of 14 cases showed high-level (+5) expression of tRB (both hyperphosphorylated and underphosphorylated RB), combined with low-level (+1) expression of uRB (underphosphorylated RB), indicating a high rate of hyperphosphorylation.

CONCLUSIONS

We could analyze the SMARCB1/INI1 gene alteration with simple methods, and SMARCB1/INI1 gene alteration was found in 12 of 14 cases. Especially, quantitative real-time PCR was a convenient and accurate method. In addition, a high rate of hyperphosphorylation of RB gene was recognized. These results suggest that the clinically aggressive character of MRT is caused by the inactivation of the SMARCB1/INI1 gene.

Extrarenal rhabdoid tumors of soft tissue: Clinicopathological and molecular genetic review and distinction from other soft-tissue sarcomas with rhabdoid features

Malignant rhabdoid tumor (MRT) of the soft tissue is a rare and highly aggressive tumor that occurs in infancy or childhood. It predominantly involves a deep axial location such as the neck or paraspinal region. Microscopically, the tumor is composed of a diffuse proliferation of rounded or polygonal cells with eccentric nuclei, prominent nucleoli and glassy eosinophilic cytoplasm containing hyaline-like inclusion bodies, arranged in sheets and nests. These characteristic 'rhabdoid cells' are also present in certain soft-tissue sarcomas such as synovial sarcoma, extraskeletal myxoid chondrosarcoma and leiomyosarcoma. The existence of rhabdoid cells in these other sarcomas is correlated with a worse prognosis for the patients. Cytogenetic and molecular analyses have shown abnormalities in the long arm of chromosome 22 and alteration of the hSNF5/INI1 (SMARCB1) gene in renal, extrarenal and intracranial MRT. This gene alteration has been considered to be a specific molecular event in MRT, but a recent study has also demonstrated frequent alteration of this gene in proximal-type epithelioid sarcoma (ES). Both MRT of soft tissue and proximal-type ES show immunoreactivity for vimentin, cytokeratin and epithelial membrane antigen. The tumor cells of proximal-type ES are also occasionally positive for CD34 and beta-catenin, whereas MRT of soft tissue has no immunoreaction for these markers. Detailed clinicopathological and immunohistochemical evaluations are necessary to distinguish MRT of soft tissue from proximal-type ES, because these tumors demonstrated a similar morphology and the same gene alteration.

Malignant rhabdoid tumor in a pregnant adult female: literature review of central nervous system rhabdoid tumors

Rhabdoid tumors of the central nervous system are uncommon, aggressive childhood malignancies. The 13 described adult cases comprise both primary CNS tumors and malignant transformation of previously existing gliomas, meningiomas, and astrocytomas. Central nervous system rhabdoid lesions of adults have been diagnosed as primary malignant rhabdoid tumors, atypical teratoid/rhabdoid tumors, and more recently, rhabdoid glioblastomas. We report a case of a 20-year-old woman in her 30th week of pregnancy who presented with headache, nausea and blurry vision. MRI revealed a large rim-enhancing mass of the right occipital lobe. Gross total resection was achieved via a right parietal-occipital craniotomy. Pathologic evaluation revealed histology, electron microscopy and immunohistochemistry consistent with the diagnosis of malignant rhabdoid tumor. FISH studies were negative for the INI-1 genetic mutations and chromosome 22q deletion associated with childhood atypical rhabdoid/rhabdoid tumor in 75% of cases. The patient delivered her infant via caesarian section prior to initiating further therapy. We briefly describe the characteristics and current understanding of rhabdoid tumors, and review the literature comparing the 12 other cases of central nervous system rhabdoid tumors in adults. Furthermore, we consider and discuss the implications of this case being the second presentation of MRT during pregnancy in only six adult female patients.

Differentiation-dependent expression and mitogenic action of interleukin-6 in human colon carcinoma cells: relevance for tumour progression

Interleukin (IL)-6 mRNA expression in general is low in normal, adenomatous and cancerous human colon mucosa, except in rather undifferentiated lesions, in which IL-6 is overexpressed. Cytokeratin (CK) 8-positive carcinoma cells were identified by double immunostaining as almost exclusive source of IL-6. Likewise, in five (sub)clones of primary culture COGA-1 and COGA-13 human colon carcinoma cells, and in three established cell lines (Caco-2/AQ, Caco-2/15 and HT-29), efficient translation of IL-6 mRNA into protein was observed only in the least differentiated COGA-13 cells. Notably, IL-1beta (5 ng/ml) enhanced IL-6 release in COGA-13 cultures by three orders of magnitude. Although all cell clones studied expressed the IL-6 receptor (IL-6R), rhIL-6 (1-100 ng/ml) had a significant effect on cellular proliferation only in highly differentiated Caco-2 cells. Our data imply that IL-6, when released from rather undifferentiated carcinoma cells, particularly in response to IL-1beta, can advance tumour progression through paracrine growth stimulation of normal or highly differentiated colon tumour cells with intact STAT-3-mediated IL-6 signalling.

Soft tissue sacrococcygeal chordoma with intracytoplasmic filamentous inclusions

Extraskeletal chordoma arising within soft tissue is a rare occurrence. We report a case of chordoma that is unusual both for its location within the subcutaneous soft tissue of the sacrococcygeal region without involvement of adjacent bones and for the presence of eosinophilic roundish inclusion bodies within the cytoplasm of tumor cells. These bodies revealed immunoreactivity for cytokeratin and a fibrillar, partly whorled structure on the electron microscopic examination, consistent with an intermediate filament-based composition. To our knowledge, this is the first report of chordoma featuring this cellular change although we do not know the significance of these bodies.

INI1 expression is retained in composite rhabdoid tumors, including rhabdoid meningiomas

Rhabdoid cells are encountered in specific entities, such as malignant rhabdoid tumor and atypical teratoid/rhabdoid tumor, as well as in composite rhabdoid tumors derived secondarily from other tumor types. Although rhabdoid tumors are uniformly aggressive, distinction of the entity from the phenotype remains important for its therapeutic implications. The majority of malignant rhabdoid tumors and atypical teratoid/rhabdoid tumors affect infants and young children, harbor chromosome 22q deletions, and inactivate the INI1/hSNF5/BAF47 tumor suppressor gene on 22q11.2. In contrast, most composite rhabdoid tumors are diagnosed in adults, with FISH detectable 22q losses the exception rather than the rule. However, this assay remains limited since 22q dosages are maintained in 20-30% of malignant rhabdoid tumors and atypical teratoid/rhabdoid tumors. Furthermore, chromosome 22 losses are common in some parent tumor types, particularly meningiomas. The recently developed INI1 antibody shows loss of nuclear expression in malignant rhabdoid tumors and atypical teratoid/rhabdoid tumors, though its status in composite rhabdoid tumors is largely unknown. Therefore, we utilized immunohistochemistry and FISH to study INI1 expression and 22q dosages, respectively, in 40 composite rhabdoid tumors, including 16 meningiomas, 15 carcinomas, three melanomas, two sarcomas, two glioblastomas, and 1 neuroblastoma. Approximately 70% of rhabdoid meningiomas had a 22q deletion, but this was rare in other tumor types. Except for one retroperitoneal leiomyosarcoma, nuclear INI1 expression was retained in all composite rhabdoid tumors, including meningiomas with 22q deletion. Therefore, we conclude that INI1 immunohistochemistry is a relatively simple, sensitive, and specific technique for distinguishing malignant rhabdoid tumor and atypical teratoid/rhabdoid tumor from composite rhabdoid tumor.

Malignant rhabdoid tumor of the liver: case report and literature review

A case of malignant rhabdoid tumor (MRT) occurring as a primary hepatic neoplasm in a 12-month-old Japanese female infant is presented. The patient had a slight fever for 2 weeks and presented with a palpable mass in her left hypochondrial region. After admission, the hepatic artery was embolized due to intra-abdominal hemorrhage arising from the tumor. The patient received chemotherapy with cisplatin, cyclophosphamide and adriacin. Despite treatment, the patient developed dyspnea, pancytopenia and disseminated intravascular coagulation. Rupture of the tumor resulted in death within 3 weeks. A limited abdominal autopsy revealed that the liver weighed 1240 g and was occupied by multiple hemorrhagic and/or necrotic tumor nodules. Histologically, neoplastic cells had an abundant eosinophilic cytoplasm containing paranuclear inclusions, and vesicular nuclei with a centrally located prominent nucleolus. Ultrastructurally, the cytoplasmic inclusions were composed of whorled filaments measuring 10 nm. Immunohistochemically, almost all of the neoplastic cells were positive for vimentin and cytokeratins (CK) 8 and 18, some were positive for CK 7 and 19, while none were positive for CK 1, 10, 13-17 and 20. The tumor cells did not express desmin, myoglobin, and alpha-fetoprotein. We found 18 cases of MRT of the liver published in English language literature and then, adding the present case, we summarized the 19 cases. Hepatic MRT is an uncommon neoplasm. However, it should be considered in the differential diagnosis of an aggressive liver neoplasm in childhood.

"Proximal-type" epithelioid sarcoma in a young girl

Epithelioid sarcoma is a rare, malignant soft-tissue neoplasm occurring on the distal extremities of young adults. Its histologic features consist of a proliferation of rounded to plump, spindle-shaped cells with abundant eosinophilic cytoplasm around areas of necrosis, simulating a granulomatous process. Recently a different type of epithelioid sarcoma has been described and named "proximal-type" epithelioid sarcoma. It is found mostly in the pelvic and perineal areas of young to middle-aged adults. On microscopic examination, the tumor is characterized by a proliferation of epithelioid-like cells with rhabdoid features in the absence of a granuloma-like pattern, and immunohistochemically it coexpresses vimentin, cytokeratin, epithelial membrane antigen, and CD34. As we found no report of proximal epithelioid sarcoma in the dermatologic literature, we describe an additional case in a 12-year-old girl. This type of tumor appears to be somewhat more aggressive than the classical, distal type and it should be considered in the differential diagnosis of tumors showing rhabdoid features, in particular extrarenal malignant rhabdoid tumor.

Novel germ-line deletion ofSNF5/INI1/SMARCB1 gene in neonate presenting with congenital malignant rhabdoid tumor of kidney and brain primitive neuroectodermal tumor

We describe a neonate who had a rare tumor combination of a malignant rhabdoid tumor of the kidney (MRTK) and a brain primitive neuroectodermal tumor (PNET). Genetic alterations of the SNF5/INI1/SMARCB1 gene were investigated by PCR-single-strand conformation polymorphism (SSCP), loss of heterozygosity (LOH), sequence, and karyotyping analyses, and the gene expression level was determined by real-time quantitative RT-PCR analysis. PCR band signals of each exon of the hSNF5/INI1 were weak or nearly undetectable in both MRTK and PNET, whereas those of the corresponding normal kidney were clearly detected. Aberrantly migrating SSCP bands led to identification of a nucleotide change in intron 8. Although this was regarded as a polymorphism, only the changed nucleotide was observed in the normal kidney of the patient. Allelic states in the parents were heterozygous for the polymorphism in the father and homozygous for the normal sequence in the mother. Thus, it was evident that a substantial genetic part of the maternal normal allele including SNF5/INI1 was deleted as a de novo germ-line mutation. In both tumors, LOH at microsatellite loci on the long arm of chromosome 22 was evident, and expression of SNF5/INI1 mRNA was drastically decreased compared to that in control tissues (0.7-3.9 vs. 123.6-153.5). Deletion of a substantial genetic part demonstrated in our patient is the novel appearance of a germ-line deletion of the SNF5/INI1 gene. Additional large somatic deletions resulted in total inactivation of the gene in both tumors. Our patient provides evidence for an important role of SNF5/INI1germ-line mutation in predisposing patients to multiple rhabdoid tumors.