Adult rhabdomyosarcoma: cross-sectional imaging findings including histopathologic correlation

Pathologic features of head and neck adult rhabdomyosarcoma: Case series

INTRODUCTION

Adult Head and neck Rhabdomyosarcomas (HNRMS) are exceedingly rare and remain challenging for pathologists.

CASES PRESENTATION

Five cases of adult HNRMS (≥19 years) were retrieved from the archives of the Department of Pathology of Hospital of Specialities in Rabat (HSR) in Morocco, over 5 years. Clinical and pathologic findings from hematoxylin and eosin slides and immunohistochemistry for Desmin and Myogenin were reviewed.

CLINICAL DISCUSSION

The median age was 33, with a men's predominance (3 M/2F). Histological analysis revealed three cases of Alveolar Rhabdomyosarcoma (RMS), one Pleomorphic RMS, and one spindle cell/sclerosing RMS. In addition to the typical histology observed in each RMS, we found tricky growth patterns that could be a source of misdiagnosis. All five cases demonstrated variable positivity for Desmin and Myogenin.

CONCLUSION

HNRMS cases have different pathological features than pediatric RMS cases. We identified rare subtypes such as pleomorphic and spindle cell/sclerotic RMS, which exhibit unusual morphological patterns.

Understanding a mass in the paraspinal region: an anatomical approach

The paraspinal region encompasses all tissues around the spine. The regional anatomy is complex and includes the paraspinal muscles, spinal nerves, sympathetic chains, Batson's venous plexus and a rich arterial network. A wide variety of pathologies can occur in the paraspinal region, originating either from paraspinal soft tissues or the vertebral column. The most common paraspinal benign neoplasms include lipomas, fibroblastic tumours and benign peripheral nerve sheath tumours. Tumour-like masses such as haematomas, extramedullary haematopoiesis or abscesses should be considered in patients with suggestive medical histories. Malignant neoplasms are less frequent than benign processes and include liposarcomas and undifferentiated sarcomas. Secondary and primary spinal tumours may present as midline expansile soft tissue masses invading the adjacent paraspinal region. Knowledge of the anatomy of the paraspinal region is of major importance since it allows understanding of the complex locoregional tumour spread that can occur via many adipose corridors, haematogenous pathways and direct contact. Paraspinal tumours can extend into other anatomical regions, such as the retroperitoneum, pleura, posterior mediastinum, intercostal space or extradural neural axis compartment. Imaging plays a crucial role in formulating a hypothesis regarding the aetiology of the mass and tumour staging, which informs preoperative planning. Understanding the complex relationship between the different elements and the imaging features of common paraspinal masses is fundamental to achieving a correct diagnosis and adequate patient management. This review gives an overview of the anatomy of the paraspinal region and describes imaging features of the main tumours and tumour-like lesions that occur in the region.

Head and Neck Sarcoma Tumor Board Survival Guide for Neuroradiologists: Imaging Findings, History, and Pathology

Sarcomas of the head and neck carry a poor prognosis as diagnosis is often delayed until a late stage of the disease. Accordingly, it is essential to be familiar with the clinical and imaging features of sarcomas to suggest an appropriate differential diagnosis for collaborating surgeons and pathologists. However, as there are only 1000-1500 cases in the United States annually, many radiologists lack experience with pertinent imaging findings of sarcoma and lack knowledge of both treatment and necessary follow-up. In this review, a brief discussion of WHO definitions and histopathology is included to decode information provided by pathologists. Finally, staging and treatments are illuminated to aid the radiologist with initial imaging staging and follow-up care. This review aims to increase the comprehensive knowledge of a neuroradiologist and further their value to the multidisciplinary tumor board.

Fisher discriminant model based on LASSO logistic regression for computed tomography imaging diagnosis of pelvic rhabdomyosarcoma in children

Computed tomography (CT) has been widely used for the diagnosis of pelvic rhabdomyosarcoma (RMS) in children. However, it is difficult to differentiate pelvic RMS from other pelvic malignancies. This study aimed to analyze and select CT features by using least absolute shrinkage and selection operator (LASSO) logistic regression and established a Fisher discriminant analysis (FDA) model for the quantitative diagnosis of pediatric pelvic RMS. A total of 121 pediatric patients who were diagnosed with pelvic neoplasms were included in this study. The patients were assigned to an RMS group (n = 36) and a non-RMS group (n = 85) according to the pathological results. LASSO logistic regression was used to select characteristic features, and an FDA model was constructed for quantitative diagnosis. Leave-one-out cross-validation and receiver operating characteristic (ROC) curve analysis were used to evaluate the diagnostic ability of the FDA model. Six characteristic variables were selected by LASSO logistic regression, all of which were CT morphological features. Using these CT features, the following diagnostic models were established: (RMS group)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${G}_{1}=-14.283+6.613{x}_{1}+5.333{x}_{2}+5.753{x}_{3}+12.361{x}_{4}+8.095{x}_{5}-0.715{x}_{6}$$\end{document}G1=-14.283+6.613x1+5.333x2+5.753x3+12.361x4+8.095x5-0.715x6; (Non-RMS group)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${G}_{2}=-2.008+3.539{x}_{1}+1.080{x}_{2}+1.154{x}_{3}+2.307{x}_{4}+1.656{x}_{5}+1.380{x}_{6}$$\end{document}G2=-2.008+3.539x1+1.080x2+1.154x3+2.307x4+1.656x5+1.380x6, where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${x}_{1}$$\end{document}x1, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${x}_{2}$$\end{document}x2, … and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${x}_{6}$$\end{document}x6 are lower than normal muscle density (1 = yes; 0 = no), multinodular fusion (1 = yes; 0 = no), enhancement at surrounding blood vessels (1 = yes; 0 = no), heterogeneous progressive centripetal enhancement (1 = yes; 0 = no), ring enhancement (1 = yes; 0 = no), and hemorrhage (1 = yes; 0 = no), respectively. The calculated area under the ROC curve (AUC) of the model was 0.992 (0.982–1.000), with a sensitivity of 94.4%, a specificity of 96.5%, and an accuracy of 95.9%. The calculated sensitivity, specificity and accuracy values were consistent with those from cross-validation. An FDA model based on the CT morphological features of pelvic RMS was established and could provide an easy and efficient method for the diagnosis and differential diagnosis of pelvic RMS in children.

Computed tomography imaging features of malignant 'triton' tumor to facilitate its clinical diagnosis: report of two cases

Background

Malignant ‘triton’ tumor is an extremely rare subtype of malignant periphery nerve sheath tumors. Clinical diagnosis of malignant triton tumor is difficult before surgery due to its low incidence and the lack of knowledge. Therefore, to describe and summarize the CT imaging characteristics of malignant triton tumor is of great assistance for early and preoperative diagnosis.

Case presentation

Two cases suspected of MTT by CT scan before operation were closely observed. The diagnosis of malignant triton tumor was eventually confirmed by immunochemical assay, which verified speculation of CT scans. Huge, irregular, well-circumscribed lobulated mass-like shadows can be observed from these patients by CT scans. Besides, heterogeneity of density within the body of tumor was well-established by CT scans, together with linear septum. Meanwhile, CT scans demonstrated that calcifications were remarkable at the margin of tumor body.

Conclusions

Some CT image features from two cases were presented as a reference for the preoperative consideration of MTT: (i) enormity of mass-like shadow; (ii) presence of well-circumscribed lobulated shape; (iii) septum within the well-defined mass accompanied with hemorrhage, necrosis and cystic changes as well as calcification, especially within neurofibromatosis type 1 patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00848-9.

Computed tomography (CT) features of pelvic rhabdomyosarcoma (RMS) in children

BACKGROUND

Currently, there are few literature reports on the CT features of pelvic rhabdomyosarcoma, most of which exist in the form of case reports, and some literature reports have suggested that CT features of pelvic rhabdomyosarcoma lack specificity. This study was designed to investigate the CT features of pelvic RMS in children to provide imaging evidence for clinical diagnosis.

METHODS

We retrospectively reviewed radiographic and clinical data of all paediatric patients with pelvic neoplastic lesions pathologically proven to be malignant in our hospitals from January 2012 through March 2021. The data of the included paediatric patients were divided into two groups according to whether the pathology results indicated RMS. CT features of RMS (n= 37) and non-RMS (n= 91) were compared by two abdominal radiologists.

RESULTS

A total of 9 CT features were statistically significant for the diagnosis of pelvic RMS in children (p＜0.05). The sensitivity (range, 0.64-0.74) and specificity (range, 0.86-0.93) of the CT features showing multinodular fusion, surrounding blood vessels, and heterogeneous progressive centripetal enhancement were both relatively high. The CT features indicating lower than muscle density, necrosis, non-calcification and non-haemorrhage exhibited high specificity (range, 0.86-0.97), but the sensitivity (range, 0.32-0.40) was relatively low, while the sensitivity (range, 0.37-0.46) and specificity (range, 0.75-0.83) of other CT features used for diagnosing pelvic RMS, namely, lobulated and lymphatic metastasis, were both relatively low.

CONCLUSION

Pelvic rhabdomyosarcoma in children has its own specific CT features.

Immunohistochemical expression of cyclin-dependent kinase inhibitors p16 and p57 in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a highly malignant cancer and is the most common soft tissue sarcoma in children and adolescents, but it is rare in adults (<1% of all adult malignancies). Altered expression and molecular abnormalities of cell-cycle-regulatory proteins are one of the most prominent features in RMS. Therefore, we evaluated the expression of cyclin-dependent kinase inhibitors p57 and p16, as well as p16 methylation status, along with clinicopathological characteristics and overall survival (OS) in RMS patients. This analysis was conducted on 23 pediatric and 44 adult patients. There was a male predominance in both groups and extremities were the most frequent tumor site. In adults, alveolar and pleomorphic types were almost equally represented. The majority of pediatric tumors were low grade, whereas, in adults, only one patient had a low-grade tumor. Seven pediatric (30.43%) and eight adult (18.18%) patients had a low p16 expression. The analysis of methylation status of the p16 promoter showed the presence of methylated allele only in one sample with pleomorphic histology. Six (26.1%) pediatric and 15 (34.1%) adult patients had low p57 expression, while in 17 (73.9%) pediatric and 29 (65.9%) adult patients it was assessed as high. Ninetyone percent of the pediatric patients and 32.6% of adults were alive at the end of the observational period. In adults, significant associations were found between OS and age (P = 0.020), gender (P = 0.027), tumor size (P < 0.001), lymph node status (P < 0.001), presence of metastases (P = 0.015), and p57 expression (P = 0.039). Stratification by histological type showed the correlation of low p57 expression (P = 0.030) and worse OS of patients with alveolar RMS. Univariate analysis identified age > 50 yrs. (HR 2.447), tumors > 5 cm (HR 21.31), involvement of regional lymph nodes (HR 3.96), the presence of metastases (HR 2.53), and low p57 expression (HR 2.11) as predictors of lower OS. Tumor size, regional lymph nodes involvement, and metastases were the independent predictors after multivariate analysis, while p57 did not predict OS in an independent way. In summary, although p57 was not confirmed to be an independent predictor of OS, our results indicate that its low expression may be the marker of aggressive phenotype and poor prognosis in adult RMS patients. Also, our findings suggest that epigenetic inactivation of p16 is not important in the pathogenesis of rhabdomyosarcoma.

Radiologic-Pathologic Correlation of Primary Retroperitoneal Neoplasms

An earlier incorrect version of this article appeared in print. The online version is correct.

Magnetic resonance imaging of soft tissue sarcoma: features related to prognosis

Magnetic Resonance Imaging is a fundamental tool in the evaluation of soft tissue sarcoma. Imaging features are relevant for the assessment of treatment strategies, surgical planning and also for patients' prognosis prediction. Among soft tissue sarcoma and also other malignancies, the size of the mass is usually considered the prognostic key element in diagnostic imaging. Moreover, several other features should be obtained from MRI studies with prognostic implications in all type of soft tissue sarcoma: peritumoral enhancement, signs of necrosis, deep location, ill-defined borders/signs of infiltrations. Focusing on soft tissue sarcoma subtypes, some other magnetic resonance imaging features are more specific and related to prognosis. In myxofibrosarcoma the magnetic resonance imaging "tail sign" and a "water-like" appearance on fluid-sensitive sequences, due to rich myxoid matrix content, are both associated with higher risk of local recurrence after surgical excision; nevertheless, the "tail sign" is also related to a higher risk of distant metastases at diagnosis. The "tail sign" is associated with higher risk of local recurrence after surgical excision in undifferentiated pleomorphic sarcoma as well. In patients affected by synovial sarcoma, the "triple sign" identifiable in magnetic resonance imaging (T2w sequences) is associated with decreased disease-free survival and indicates the simultaneous presence of solid cellular elements (intermediate signal intensity), hemorrhage or necrosis (high signal intensity) and fibrotic regions (low signal intensity). In addition, absence of calcifications are associated with reduced disease-free survival in patients affected by synovial sarcoma. Signal heterogeneity is associated with worst prognosis in all type of soft tissue sarcoma, particularly in myxoid liposarcoma. In recent years, several new quantitative tools applied on magnetic resonance imaging have been proved to predict patients' prognosis. Above all the new tools, radiomics seems to be one of the most promising, and, has been proved to have the capability in discriminating low-grade from high-grade soft tissue sarcomas. Therefore, magnetic resonance imaging studies in patients with soft tissue sarcoma should be accurately evaluated and their results should be taken into account for prognostic assessment.

Multimodality imaging of adult rhabdomyosarcoma: the added value of hybrid imaging

Rhabdomyosarcoma (RMS) represents more than 50% of paediatric soft tissue tumours. Conversely, it is extremely rare among adults, where it shows peculiar biological and clinical features that are still poorly investigated. RMS patients should be referred to a Sarcoma Centre, where the contribution of experienced radiologists plays a relevant role in the diagnostic assessment of the disease, including precise localisation, staging, image-guided biopsy, response evaluation after treatment and follow-up. Besides CT and MRI, hybrid imaging including positron emission tomography (PET)/CT and PET/MRI are giving an increasing contribution to provide functional insights about tumour biology and to improve the diagnostic accuracy of the imaging work-up. This review paper provides a revision of the pathology, clinical and radiological features of adult RMS, with a particular focus on the growing role of hybrid PET-based imaging.

Imaging of Abdominal Wall Masses, Masslike Lesions, and Diffuse Processes

Abdominal wall masses, masslike lesions, and diffuse processes are common and often incidental findings at cross-sectional imaging. Distinguishing among these types of masses on the basis of imaging features alone can be challenging. The authors present a diagnostic algorithm that may help in distinguishing different types of abdominal wall masses accurately. Hernias may mimic discrete masses at clinical examination, and imaging is often ordered for evaluation of a possible abdominal wall mass. Once a discrete mass is confirmed to be present, the next step is to determine if it is a fat-containing, cystic, or solid mass. The most common fat-containing masses are lipomas. Fluid or cystic masses include postoperative abscesses, seromas, and rectus sheath hematomas. Solid masses are the most common abdominal wall masses and include desmoid tumors, sarcomas, endometriomas, and metastases. Multiple masses and other diffuse abdominal wall processes are often manifestations of an underlying condition or insult. The most frequently found diffuse processes are multiple injection granulomas from administration of subcutaneous medication. This article offers an algorithmic approach to characterizing abdominal wall masses on the basis of their composition and reviews abdominal wall diffuse processes. Online supplemental material is available for this article. ^©RSNA, 2020.

Comprehensive Review of Abdominopelvic Mesenchymal Tumors With Radiologic Pathologic Correlation and Update on Current Treatment Guidelines-Part 2

Soft-tissue sarcomas are a diverse group of rare mesenchymal malignancies accounting for only 1% of all solid adult malignancies. These have been categorized in 12 broad groups by the World Health Organization (WHO) with their recent update in 2013. Majority of them lack specific imaging features serving as imaging conundrums for a radiologist. These are often large masses at presentation as they are asymptomatic or cause vague clinical symptoms. These tumors are challenging for surgeons as well as they find it difficult to achieve complete resection because of complex intra-abdominal anatomy and their close relationship with critical structures. Often, a multidisciplinary approach is required to decide on the most appropriate management for these complex cases so as to provide optimal patient care. Knowledge of the WHO classification, pathologic features, and treatment options available helps the radiologist make a meaningful contribution in multidisciplinary discussions of such cases and overall patient care. Liposarcoma (well-differentiated and dedifferentiated liposarcomas), leiomyosarcoma, and gastrointestinal stromal tumor are the 3 most common primary intra-abdominal sarcomas. In part 1 of this article, general features of soft-tissue sarcomas and some of the common tumors from WHO category 1-4 found in abdomen and pelvis are discussed. Part 2 will focus on common tumors from remainder of the WHO categories.

Soft Tissue Special Issue: Imaging of Bone and Soft Tissue Sarcomas in the Head and Neck

Bone and soft tissue sarcomas of the head and neck are a heterogenous group of tumors with overlapping features. Distinguishing between the various subtypes is challenging but necessary for appropriate diagnosis and management. The purpose of this article is to discuss the role of imaging in evaluating head and neck tumors, provide a general radiographic approach in differentiating between benign versus malignant lesions and give examples of selected subtypes of bone and soft tissue sarcomas in the head and neck with classic or pathognomonic imaging findings.

Embryonal rhabdomyosarcoma within abdomen and pelvis in an adult

Rhabdomyosarcoma arising in abdomen and pelvis is an uncommon but important type of soft tissue sarcoma, posing a great challenge for clinicians. Sporadic cases of intra-abdominal rhabdomyosarcoma were reported, but mostly in pediatrics. We demonstrated a rare case of primary abdominopelvic rhabdomyosarcoma in an elderly woman who presented with a notable increase in abdominal circumference and constipation. Abdominal magnetic resonance imaging showed a huge mass throughout the abdomen and pelvis. Cytoreductive surgery was performed by gynecologists due to the suspicious diagnosis of disseminated leiomyosarcoma. However, the final pathological analysis revealed embryonal rhabdomyosarcoma. Although adjuvant chemotherapy was administered, localized recurrence was identified 6 months after the initial operation. Gynecologists and radiologists should be aware of it so it can be listed in the differential diagnosis of masses that primarily arise in the abdomen and pelvis.

Imaging in Soft Tissue Sarcomas: Current Updates

Soft tissue sarcomas (STS) are heterogeneous malignant tumors that have nonspecific imaging features. A combination of clinical, demographic, and imaging characteristics can aid in the diagnosis. Imaging provides important information regarding the tumor extent, pretreatment planning, and surveillance of patients with STS. In this article, we illustrate the pertinent imaging characteristics of the commonly occurring STS and some uncommon sarcomas with unique imaging characteristics.

MR Imaging of Atraumatic Muscle Disorders

Atraumatic disorders of skeletal muscles include congenital variants; inherited myopathies; acquired inflammatory, infectious, or ischemic disorders; neoplastic diseases; and conditions leading to muscle atrophy. These have overlapping appearances at magnetic resonance (MR) imaging and are challenging for the radiologist to differentiate. The authors organize muscle disorders into four MR imaging patterns: (a) abnormal anatomy with normal signal intensity, (b) edema/inflammation, (c) mass, and (d) atrophy, highlighting each of their key clinical and imaging findings. Anatomic muscle variants, while common, do not produce signal intensity alterations and therefore are easily overlooked. Muscle edema is the most common pattern but is nonspecific, with a broad differential diagnosis. Autoimmune, paraneoplastic, and drug-induced myositis tend to be symmetric, whereas infection, radiation-induced injury, and myonecrosis are focal asymmetric processes. Architectural distortion in the setting of muscle edema suggests one of these latter processes. Intramuscular masses include primary neoplasms, metastases, and several benign masslike lesions that simulate malignancy. Some lesions, such as lipomas, low-flow vascular malformations, fibromatoses, and subacute hematomas, are distinctive, but many intramuscular masses ultimately require a biopsy for definitive diagnosis. Atrophy is the irreversible end result of any muscle disease of sufficient severity and is the dominant finding in disorders such as the muscular dystrophies, denervation myopathy, and sarcopenia. This imaging-based classification, in correlation with clinical and laboratory data, will aid the radiologist in interpreting MR imaging findings in patients with atraumatic muscle disorders. ^©RSNA, 2018.

[Imaging characteristics of malignant and benign lesions of skeletal muscle]

There are many different tumors and tumor-like lesions with variable biological behavior that may affect the skeletal musculature. The aim of this study was to review the different intramuscular lesions and to provide a classification based on their radiological patterns. Intramuscular lesions can present as solid, liquid, semiliquid or fat equivalent manifestations and also as diffuse muscle enlargement and muscle calcification. Additionally, lesions with mixed patterns of the aforementioned alterations can also occur. Benign and malignant muscle lesions can often manifest with identical radiological patterns, which is why a certain differentiation is often difficult. A systematic radiological description and when possible assignment with respect to etiology and dignity depending on the patient history is necessary in order to recommend a subsequent histological confirmation or to avoid unnecessary confirmation.

Soft-Tissue Sarcomas of the Abdomen and Pelvis: Radiologic-Pathologic Features, Part 2-Uncommon Sarcomas

Soft-tissue sarcomas occurring in the abdomen and pelvis are an uncommon but important group of malignancies. Recent changes to the World Health Organization classification of soft-tissue tumors include the movement of gastrointestinal stromal tumors (GISTs) into the soft-tissue tumor classification. GIST is the most common intraperitoneal sarcoma. Liposarcoma is the most common retroperitoneal sarcoma, and leiomyosarcoma is the second most common. GIST, liposarcoma, and leiomyosarcoma account for the majority of sarcomas encountered in the abdomen and pelvis and are discussed in part 1 of this article. Undifferentiated pleomorphic sarcoma (previously called malignant fibrous histiocytoma), dermatofibrosarcoma protuberans, solitary fibrous tumor, malignant peripheral nerve sheath tumor, rhabdomyosarcoma, extraskeletal chondro-osseous sarcomas, vascular sarcomas, and sarcomas of uncertain differentiation uncommonly arise in the abdomen and pelvis and the abdominal wall. Although these lesions are rare sarcomas and their imaging features overlap, familiarity with the locations where they occur and their imaging features is important so they can be diagnosed accurately. The anatomic location and clinical history are important factors in the differential diagnosis of these lesions because metastasis, more-common sarcomas, borderline fibroblastic proliferations (such as desmoid tumors), and endometriosis have imaging findings that overlap with those of these uncommon sarcomas. In this article, the clinical, pathologic, and imaging findings of uncommon soft-tissue sarcomas of the abdomen and pelvis and the abdominal wall are reviewed, with an emphasis on their differential diagnosis.

Spindle cell/sclerosing rhabdomyosarcoma with intracranial invasion without destroying the bone of the skull base: a case report and literature review

Spindle cell/sclerosing rhabdomyosarcoma (ssRMS) is a new subtype of rhabdomyosarcoma included in the World Health Organization soft tissue and bone tumor classification in 2013. Despite the increasing number of reported cases of ssRMS, the imaging characteristics of ssRMS are not established. Herein, we present the case of an elderly Japanese woman with ssRMS of the masticator space with intracranial invasion without destruction of the adjacent bone. Attention should be paid to the presence of intracranial infiltration that may indicate a worse prognosis. Tumor growth without bone destruction could be a key finding to differentiate ssRMSs from conventional subtypes of rhabdomyosarcoma.

A Rare Case of Adult Rhabdomyosarcoma

Background

Rhabdomyosarcoma is a rare, soft tissue malignancy, diagnosed particularly in adults. It commonly metastasizes to the bone marrow. We present a rare case of an adult rhabdomyosarcoma which illustrates the importance of magnetic resonance imaging in identifying early changes in the internal bone structure.

Case Report

A 50-year-old male presented with acute urinary retention. The patient initially had a CT scan of the lumbar spine which only revealed a protrusion of the L5–S1 intervertebral disc and no apparent cause for the patient’s symptoms. One week later, an MRI was performed which showed extensive bone marrow metastases throughout the lumbar spine and a soft tissue mass in the lower sacral region. The bony metastases were not evident on the CT scan and the soft tissue mass was out of the coverage area of the CT. Subsequent biopsy of the soft tissue mass was performed and histopathology concluded the tissue to be a rhabdomyosarcoma. Unfortunately, the patient died one week after diagnosis.

Conclusions

Although adult rhabdomyosarcomas are very rare, this case highlights the advantage of MRI over CT in identifying early changes in the internal bone structure. Therefore, CT should not be relied upon to exclude bony metastases, particularly in the setting of primary cancer with a known tendency to metastasize to the bone marrow.

Primary Pleomorphic Rhabdomyosarcoma of Thyroid Gland in an Adult Patient: A Case Report

Thyroid sarcoma is a very rare entity, accounting for less than 1% of all malignant thyroid tumours. Rhabdomyosarcoma (RMS) is a sarcoma subtype, which is more common in children and adolescents. In this case, a 68-year old man, presented with hoarseness and diagnosed with pleomorphic RMS, was explored. No study of primary thyroid pure RMS has been reported in the literature, with the exception of the case reports of differentiated RMS.

Sinonasal Neoplasia - Clinicopathological Profile And Importance of Computed Tomography

BACKGROUND

Nasal cavity and Paranasal sinus malignancies are very rare, in which maxillary sinus is the commonest, followed by ethmoid, frontal and sphenoid sinus. Computed Tomography (CT) & Magnetic Resonance Imaging (MRI) play a key role in diagnosis, staging and management of paranasal sinuses and nasal pathologies. Multiplanar imaging in CT helps better imaging of critical anatomical areas. Aim of our study was to study the incidence, clinical features, CT features and its importance in the management of sinonasal neoplasms.

MATERIALS AND METHODS

This prospective study was carried out in a tertiary care hospital of MP, India. Consecutive 40 histologically proven cases of sinonasal neoplasia who visited the Department of Otorhinolaryngology and Radiotherapy are included in our study. Demography and clinical features were recorded. Cases of nasal and paranasal sinus masses diagnosed on CT attending ENT and Radiotherapy OPD or admitted in the Radiotherapy ward forms the material of this study. This included patients of both sexes and all ages. Histopathological examination was asked to confirm the diagnosis made on CT.

RESULTS

There were total 40 cases of sinonasal neoplasia among which 24 were benign. Almost all the benign cases were seen in the age group <40 y with mean age of 20 y and most of the malignant cases were seen in the age group above 40 y with mean age of 55 y. In our study we found male preponderance with male female ratio of 4:1 in both benign and malignant conditions. The commonest presenting symptoms of the patients with sinonasal masses in our study was nasal obstruction (75%) and nasal discharge (67.5%) followed by nasal mass (65%), epistaxis (62.5%) and headache (60%). Angiofibroma and papilloma were the commonest benign lesions. Commonest malignant lesion was squamous cell carcinoma. Of the malignant Sinonasal tumours studied in our series, maxillary sinus was involved in 13, ethmoid sinuses and nasal cavity in 10 cases each, and frontal sinuses in 2 cases.

CONCLUSION

Contrast enhanced computed tomography with multiplanar reconstruction is an excellent modality for imaging sinonasal masses. CT can define the character of the sinonasal mass, thus differentiating benign from malignant. CT helps better imaging of critical anatomical areas and helpful in planning treatment procedures such as surgery and radiotherapy.

Malignant and benign lesions of the skeletal musculature

There are several tumors and tumorlike conditions with variable biological behavior that may involve the skeletal musculature. The aim of this work was to review different intramuscular lesions and to provide a classification of muscle lesions based on their radiological patterns as well as to provide as a pictorial essay the imaging characteristics of typical muscle lesions. Radiologically, intramuscular lesions can manifest as solid masses, liquid or semiliquid masses, fat-containing lesions, diffuse muscle enlargement, and muscle calcifications. Additionally, lesions with mixed patterns can also occur. It is noteworthy that different malignant or benign muscle lesions can manifest with identical radiological patterns.

Computed tomography and magnetic resonance imaging observations of rhabdomyosarcoma in the head and neck

Head and neck (HN) rhabdomyosarcoma (RMS) is an aggressive malignancy, which is rarely encountered and is commonly misdiagnosed as another type of tumor. The aim of the present study was to investigate the computed tomography (CT) and magnetic resonance imaging (MRI) features of HNRMS and analyze the correlations between the imaging observations and the pathological subtypes. A total of 10 HNRMS patients (three males and seven females; median age, 16 years) were reviewed retrospectively by only CT (n=1), only MRI (n=2), as well as CT and MRI (n=7). In addition, the clinical data, imaging observations and pathological results were recorded and analyzed. The origins of the 10 HNRMSs (eight embryonal and two alveolar subtypes) included the ethmoid sinus (n=4), maxillary sinus (n=1), orbit (n=3), nasopharynx (n=1) and frontotemporal subcutaneous area (n=1). On the CT and MRI images, the soft-tissue masses exhibited ill-defined borders (n=9), bony destruction (n=10), multi-cavity growth (n=7) and cervical lymph node metastasis (n=2), whereas calcification and hemorrhaging were not identified. On CT, eight of the HNRMSs appeared slightly hypodense (2/8) or isodense (6/8) with homogeneous enhancement (4/4). On T1-weighted images (WI), nine tumors exhibited isointensity (9/9) and on T2WI, six tumors demonstrated homogeneous hyperintensity with homogeneous enhancement on contrast-enhanced (CE)-T1WI. In addition, three embryonal RMSs, which originated from the ethmoid sinus, exhibited heterogeneous hyperintensity on T2WI and nodule-shaped enhancement patterns on CE-T1WI. The results of the present study indicated that MRI may accurately demonstrate the location and extent of HNRMS and that the imaging features of HNRMS may be similar to those of other tumors. However, a tumor exhibiting heterogeneous hyperintensity on T2WI and a nodule-shaped enhancement pattern on CE-T1WI in the ethmoid sinus may present specific MRI features, which clearly indicates the botryoid subtype of embryonal RMS.

Pelvic alveolar rhabdomyosarcoma in a young adult

Rhabdomyosarcomas are soft-tissue tumors, rare in adults. Accounting for nearly 5% of childhood cancers, they represent less than 0.03% of adult malignancies (1, 2). Three different subtypes of rhabdomyosarcoma have been described (embryonal, alveolar and pleomorphic), making up approximately 50%, 30%, and 20% of the cases, respectively (3). Although the definitive diagnosis is made pathologically, some distinguishing features among these subtypes, and between rhabdomyosarcomas and other soft-tissue tumors, can be suggested on MRI and CT. We present an interesting case of a 20-year-old female with a locally aggressive pelvic alveolar rhabdomyosarcoma. While the prognosis has improved with newer treatment techniques, overall survival rates remain poor. Our case study presents typical features of a rare disease, which can often present a diagnostic dilemma for clinicians.

Tail-end troubles: imaging of soft-tissue buttock tumours

Primary soft-tissue buttock tumours are relatively common entities, although they are infrequently reported in the literature. The buttock can be a difficult anatomical site to treat soft-tissue tumours due to the proximity of the sciatic nerve and the propensity of tumours at this site to extend into the pelvis and perineum. Therefore, the radiologist plays an important role in the multidisciplinary assessment of these lesions. Cross-sectional imaging, principally magnetic resonance imaging, is used to determine the exact location and extension of the tumour. Furthermore, certain tumours have characteristic imaging appearances that can help to establish a suitably ordered differential diagnosis. From our prospectively maintained database at The Royal Marsden Hospital, including 225 cases that were treated at the Sarcoma Unit over a 30 year period, we present examples of benign and malignant primary soft-tissue buttock tumours and describe the pertinent imaging characteristics, with emphasis on computed tomography and magnetic resonance imaging findings.

Imaging features of primary and secondary adult rhabdomyosarcoma

OBJECTIVE

Rhabdomyosarcomas are rare and aggressive soft-tissue sarcomas in adults. The purpose of this article is to describe the imaging features of primary and secondary adult rhabdomyosarcomas utilizing MRI, CT, and (18)F-FDG PET/CT.

CONCLUSION

MRI is the imaging technique of choice for the evaluation of primary rhabdomyosarcoma involving most body sites (extremity, pelvis, head, and neck), with the added advantages of diffusion-weighted imaging and whole-body MRI for staging. CT and FDG PET/CT play major roles in the evaluation of metastatic disease. Because the imaging features of adult rhabdomyosarcoma are nonspecific, other parameters, such as clinical findings, age, site, lymphadenopathy, and metastatic disease, should be combined to narrow the differential diagnosis.

Embryonal rhabdomyosarcoma of the auricle in a child

We describe the diagnosis and management of a child with embryonal rhabdomyosarcoma of the auricle and emphasize both clinical and radiological findings of this rare condition. A nine-year-old boy presented for evaluation of a slowly enlarging left auricle mass. The mass was nodular, violaceous, semi-translucent, and hyperpigmented with an overlying pseudo-vesicular plaque. The mass appeared to involve the left cavum concha, root of the helix, superior aspect of the external auditory canal, the tragus and extend to a deep preauricular component. MR imaging documented a lobulated soft tissue mass surrounding the external auditory canal with superficial involvement of the pinna. Incisional biopsy of the mass suggested embryonal rhabdomyosarcoma. The tumor was completely removed by total auriculectomy and lateral temporal bone resection. The final diagnosis was embryonal rhabdomyosarcoma. Although rare, otolaryngologists, pediatricians, and radiologists need to consider rhabdomyosarcoma in the differential diagnosis of auricle mass in children.

Pediatric rhabdomyosarcoma at presentation: can cross-sectional imaging findings predict pathologic tumor subtype?

OBJECTIVE

The purpose of the study is to determine whether there are cross-sectional imaging features of pediatric rhabdomyosarcoma that are specific to the different pathologic subtypes of the tumor.

MATERIALS AND METHODS

Medical records of 14 pediatric patients who were diagnosed with rhabdomyosarcoma were reviewed retrospectively. Patient demographics, including age and sex, as well as final pathologic report were obtained. The initial CT, MRI, or both obtained at presentation, prior to the diagnosis being established, were reviewed by two radiologists. We recorded tumor features including site, size, margins, local extension, and presence of metastases. Presence of calcification, hemorrhage, or necrosis as well as attenuation and heterogeneity of the tumor were also recorded.

RESULTS

Ten of our fourteen patients were formally diagnosed with the embryonal subtype of rhabdomyosarcoma, while three were found to have the alveolar subtype, and one subtype was poorly differentiated. There was no significant difference in the attenuation and in the heterogeneity of the tumor between the embryonal and the alveolar subtype on CT.

CONCLUSION

Imaging features at presentation, such as attenuation and heterogeneity, could not correlate to the pathologic subtype of pediatric rhabdomyosarcoma.

[Muscular metastasis]

INTRODUCTION

Neoplasia is quite rare in myology. For unknown reasons, muscular metastasis are rarely described in cancer.

METHOD

Our work was a retrospective study with analysis of the medical literature and the presentation of one case of muscular metastasis revealed by a limitation of mouth opening in a 58-year-old Caucasian man (metastatic infiltration of the right pterygoid muscle secondary to a poorly differentiated adenocarcinoma of the lower third of the esophagus).

RESULTS

In addition to our case, we found 174 cases of cancer with muscular metastasis. Most of cases were observed in males (male/female ratio=2/1). The mean age at onset was 58.5 years (range: 13-89 years). The muscular metastasis were rarely found before the diagnosis of cancer (only in 37%), and usually appeared during disease progression, with other (extramuscular) metastases in 60% of cases. Prognosis was poor with less than 2.5% survival beyond 72 months. In most cases, muscular metastasis presented as a unique (78%), painful (61%) and palpable (63%) muscular mass, even if other asymptomatic muscular metastasis could be present. The mean localization of muscular metastasis was the lower limbs (46%), particularly in the proximal part (38% of all the muscular metastasis). The most frequent cancers were localized in lung, urinary tract, digestive tract and genital tract. When the muscular biopsy showed an "adenocarcinoma", in men the primitive cancers were localized in the digestive tract (35%), kidney (20%), and lung (18%) and in women, the genital tract and breast (23.5%). When the muscular biopsy showed a "squamous-cell carcinoma", in men the primitive cancers were localized in the lung (81%) and in women the cervix (64%).

CONCLUSION

These results highlight the importance of searching for muscular metastasis in patients with a focal, painful and palpable muscular mass. The muscular biopsy and immunohistochemical data can be helpful in identifying the primary cancer.

Imaging findings in noncraniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood. This paper is focuses on imaging for diagnosis, staging, and follow-up of noncraniofacial RMS.