Extrarenal malignant rhabdoid tumors: radiologic findings with histopathologic correlation

Evaluation of targeting autophagy for the treatment of malignant rhabdoid tumours

Malignant rhabdoid tumour (MRT) is a rare and aggressive paediatric tumour that typically arises in the kidneys or central nervous system (CNS). The malignancy often affects patients under the age of three and is associated with an extremely poor survival rate, with most deaths occurring within the first year of presentation. Thus, there is an unmet and urgent medical need for novel therapeutic strategies for this malignancy. One of the major issues when treating MRT patients is the emergence of chemoresistance. Autophagy has become an area of focus in the study of chemoresistance due to its reported dual role as both a pro-survival and pro-death mechanism. The role of autophagy in the chemotherapeutic response of MRT remains largely unknown. A greater understanding of the role of autophagy may lead to the development of therapeutic strategies to enhance chemotherapeutic effect and improve the clinical outcome of MRT patients. This study evaluated the cellular response to cisplatin, a representative chemotherapeutic agent used in the treatment of MRT, and the role of autophagy in mediating cisplatin resistance. Our results demonstrated that cisplatin induced apoptosis and autophagy concomitantly in a panel of MRT cell lines. Furthermore, inhibition of caspase-induced apoptosis with Z-VAD-FMK also inhibited autophagy levels demonstrating a complex interplay between these two pathways. In addition, blocking autophagy at the early stages of the autophagic process using the pharmacological inhibitor SAR405 or through the genetic knockdown of critical autophagic protein ATG5 by siRNA did not sensitise cells to cisplatin-induced apoptosis. Collectively, these results suggest that induction of autophagy does not appear to elicit a pro-survival effect in the chemotherapeutic response of MRT cells.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 2: vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5^th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous organ soft tissues, as well as the peripheral and autonomic nervous system.

Uncommon and peculiar soft tissue sarcomas: Multidisciplinary review and practical recommendations. Spanish Group for Sarcoma research (GEIS -GROUP). Part II

Among all Soft Tissue sarcomas there are some subtypes with low incidence and/or peculiar clinical behaviour, that need to be consider separately. Most of them are orphan diseases, whose biological characteristics imply a clearly different diagnostic and therapeutic approach from other more common sarcoma tumors. We present a brief and updated multidiciplinary review, focused on practical issues, aimed at helping clinicians in decision making. In this second part we review these subtypes: Alveolar Soft Part Sarcoma, Epithelioid Sarcoma, Clear Cell Sarcoma, Desmoplastic Small Round Cell Tumor, Rhabdoid Tumor, Phyllodes Tumor, Tenosynovial Giant Cell Tumors, Myoepithelial Tumor, Perivascular Epithelioid Cell Neoplasms (PEComas), Extraskeletal Myxoid Chondrosarcoma, NTRK-fusions Sarcomas. Most of them present their own radiological and histopathological feautures, that are essential to know in order to achieve early diagnosis. In some of them, molecular diagnosis is mandatory, not only in the diagnosis, but also to plan the treatment. On the other hand, and despite the low incidence, a great scientific research effort has been made to achieve new treatment opportunities for these patients even with approved indications. These include new treatments with targeted therapies and immunotherapy, which today represent possible therapeutic options. It is especially important to be attentive to new and potential avenues of research, and to promote the conduct of specific clinical trials for rare sarcomas.

Pediatric Primary Hepatic Tumors: Diagnostic Considerations

The liver is the third most common site of abdominal tumors in children. This review article aims to summarize current evidence surrounding identification and diagnosis of primary hepatic tumors in the pediatric population based upon clinical presentation, epidemiology, and risk factors as well as classical imaging, histopathological, and molecular diagnostic findings. Readers will be able to recognize the features and distinguish between benign and malignant hepatic tumors within different age groups.

Malignant Rhabdoid Tumor of the Mediastinum: A Case Report and Literature Review

Malignant rhabdoid tumor (MRT) of the mediastinum is an aggressive tumor that is extremely rare. To date, only 24 cases of the mediastinal MRT have been reported in adults and 9 cases in the pediatric age group under the age of 18 years. We report a rare case of such tumor and review the literature on its clinical and imaging features as well as its treatment and prognostic outcomes.

Intradural lumbosacral malignant extrarenal rhabdoid tumor: a case report

BACKGROUND

Rhabdoid tumors are highly malignant tumors predominantly affecting the pediatric population. When these tumors occur outside of the kidneys, they are referred to as malignant extrarenal rhabdoid tumors (MERT), a rare highly aggressive subtype. Less commonly, these tumors involve the neuro-axis.

OBJECTIVE

Here we present a case of a 15-year-old girl with intradural MERT of the lumbosacral spine who presented with back pain, sudden worsening of lower extremity strength, and complete loss of bowel and bladder control.

RESULTS

The patient's tumor showed loss of INI-1 and negative staining for cytokeratin AE1AE3, CD99, and SOX10.

CONCLUSIONS

To our knowledge, there are no previous case reports of MERT with intradural lumbosacral spinal involvement.

[Extrarenal rhabdoid tumor: A review of literature and a report of cases with atypical morphology]

Extrarenal extracranial rhabdoid tumor (EERT) is a rare malignant pediatric tumor characterized by extremely aggressive behavior, rapid metastatic spread, low survival rates, and no targeted therapy. The morphological diagnosis of classical cases of EERT is not difficult and it is based on its characteristic histologic pattern and immunohistochemical findings in a relatively short time, which allows one to immediately initiate therapy. The paper describes two cases of ERRT in the complete absence of classical rhabdoid morphology, as revealed by light microscopy when the material was primarily assessed. The final diagnostic search could establish a diagnosis of EERT in both cases on the basis of immunohistochemical findings.

Disseminated Malignant Rhabdoid Tumor of the Head and Neck

Disseminated extrarenal malignant rhabdoid tumors of the head and neck are very rare, but aggressive tumors. Although the features on radiological imaging may be nonspecific, the imaging is useful for assessing the extent of tumor involvement. Key pathologic features are those of a cellular "blue cell tumor" with variable rhabdoid appearance. These cells express a combination of markers usually viewed as characteristic of diverse lines of differentiation, including EMA, cytokeratins, smooth muscle markers, and GFAP, and occasionally synaptophysin. At a molecular level, the entity is defined by mutations or alterations in the SMARB1/INI1 gene resulting in loss of INI1 expression. Diagnostic features include rhabdoid cells, expression of keratin with absence of desmin, S100 protein and CD34, and loss of INI1 expression. These features are exemplified in this sine qua non radiology-pathology correlation article.

Malignant extrarenal rhabdoid tumor: a case report

The fetal extrarenal rhabdoid tumor is a highly aggressive and rare neoplasm that mostly occurs in the first year of life. In this case, a remarkably enlarged right upper arm was diagnosed in a male fetus at 31+2 weeks of gestation. Because of a fast progressive tumor volume and signs of fetal distress, a cesarean section was performed at 34 weeks of gestation. The preterm baby showed a blue livid tumor reaching from the right elbow up to the shoulder that resulted in an extrarenal rhabdoid tumor on histopathologic analysis. A therapeutic trial with cyclophosphamide was not effective and the child died at the age of 26 days because of multi-organ failure.

Malignant rhabdoid tumor of the tongue: A rare occurrence

Malignant rhabdoid tumors (MRTs) are highly aggressive neoplasms that most commonly occur in the kidneys of young children. Malignant rhabdoid tumor of the tongue is an extremely rare entity and very few have been reported in the literature. The course of extra-renal MRT is short and its prognosis is very poor. A 19-year-old female presented with a progressive swelling and restricted mobility of the tongue for over 3 months duration. We present here a locally advanced case of MRT of the tongue, its diagnosis, management and review of the literature related to it.