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

Orthopedic manifestations of Li-Fraumeni syndrome: Prevention and treatment of a polymorphic spectrum of malignancies

Li-Fraumeni syndrome (LFS) is a rare hereditary cancer predisposition syndrome characterized by a heightened risk of developing various malignancies at an early age. Emerging evidence suggests a correlation between LFS and orthopedic manifestations, underscoring the importance of orthopedic screening in individuals with this syndrome. Pediatric cancer is rare. It is estimated that more than 10%-15% of tumors are secondary to a pathogenic variant in a cancer predisposition gene. More than 100 cancer predisposition genes and their association with syndromes or isolated tumors have been identified. LFS is one of those who have been most widely described. Patients with this syndrome present a high risk of developing one or more tumors. Its knowledge enables the establishment of a follow-up protocol for the patient and affected family members, facilitating early detection of new tumors and reducing tumor and treatment-related morbidity and mortality. The primary objective of this invited editorial article is to provide a thorough review of the existing knowledge of LFS and its polymorphic spectrum of related malignancies, with a focus on aspects directly linked to orthopedic manifestations. Another objective is to offer an update on the most modern prevention, treatment and follow up guidelines that could be useful for the physicians dealing with this cohort of patients.

Imaging of the Sinonasal Cavities

This article describes the various abnormalities that affect the sinonasal cavities and discusses inflammations, tumors, and tumor-like conditions. Specific imaging evaluations that focus on the sinonasal cavities are described in more detail.

Evaluation of clinical and imaging features for differentiating rhabdomyosarcoma from neuroblastoma in pediatric soft tissue

Background

In this study, we developed a nomogram predictive model based on clinical, CT, and MRI parameters to differentiate soft tissue rhabdomyosarcoma (RMS) from neuroblastoma (NB) in children preoperatively.

Materials and methods

A total of 103 children with RMS (n=37) and NB (n=66) were enrolled in the study from December 2012 to July 2023. The clinical and imaging data (assessed by two experienced radiologists) were analyzed using univariate analysis, and significant factors were further analyzed by multivariable logistic regression using the forward LR method to develop the clinical model, radiological model, and integrated nomogram model, respectively. The diagnostic performances, goodness of fit, and clinical utility of the integrated nomogram model were assessed using the area under the curve (AUC) of the receiver operator characteristics curve (ROC) with a 95% confidence interval (95% CI), calibration curve, and decision curve analysis (DCA) curves, respectively. Diagnostic efficacy between the model and radiologists' interpretations was examined.

Results

The median age at diagnosis in the RMS group was significantly older than the NB group (36.0 months vs. 14.5 months; P=0.003); the fever rates in RMS patients were significantly lower than in patients with NB (0.0% vs.16.7%; P=0.022), and the incidence of palpable mass was higher in patients with RMS compared with the NB patients (89.2% vs. 34.8%; P<0.001). Compare NB on image features: RMS occurred more frequently in the head and neck and displayed homogeneous density on non-enhanced CT than NB (48.6% vs. 9.1%; 35.3% vs. 13.8%, respectively; all P<0.05), and the occurrence of characteristics such as calcification, encasing vessels, and intraspinal tumor extension was significantly less frequent in RMS children compared to children with NB (18.9% vs. 84.8%; 13.5% vs. 34.8%; 2.7% vs. 50.0%, respectively; all P <0.05). Two, three, and four features were identified as independent parameters by multivariate logistic regression analysis to develop the clinical, radiological, and integrated nomogram models, respectively. The AUC value (0.962), calibration curve, and DCA showed that the integrated nomogram model may provide better diagnostic performance, good agreement, and greater clinical net benefits than the clinical model, radiological model, and radiologists' subjective diagnosis.

Conclusion

The clinical and imaging features-based nomogram has potential for helping radiologists distinguish between pediatric soft tissue RMS and NB patients preoperatively, and reduce unnecessary interventions.

Synovial sarcoma in the prevertebral space can mimic malignant neurogenic neoplasm: Case report and literature review

Synovial sarcoma, a rare malignant neoplasm with a poor prognosis, accounts for approximately 5%-10% of all primary soft-tissue malignancies worldwide. Typically affecting adolescents and young adults, it primarily manifests near the joints of the lower extremities. This study aimed to demonstrate that this tumor can also affect the prevertebral space. A 32-year-old male patient presented at our outpatient clinic with a 2-month history of upper limb numbness and a 1-month complaint of palpable neck mass. Imaging studies revealed a bulky, lobulated, and heterogeneous mass exhibiting heterogeneous enhancement. Furthermore, the mass caused expansion of the neuroforamen in the neck, initially suggesting a diagnosis of malignant schwannoma. However, a histopathologic examination suggested synovial sarcoma. The article provided a comprehensive review of the clinical, pathological, and radiological features of this condition. Additionally, it explored current treatment options and prognoses by referencing relevant literature.

The magnetic resonance characteristics of sinonasal rhabdomyosarcoma in adults: analysis of 27 cases and comparison with pathological subtypes

BACKGROUND

Sinonasal rhabdomyosarcoma (RMS) in adults is extremely rare, and early diagnosis and treatment are crucial to improve the patient's prognosis. The purpose of this study was to evaluate the magnetic resonance imaging (MRI) findings of sinonasal RMS in adults and analyze the correlations between the imaging features and pathological subtypes.

METHODS

We reviewed 27 patients with pathologically proven RMS of the nasal cavity and paranasal sinuses, including embryonal RMS (ERMS) in 14 patients, alveolar RMS (ARMS) in seven patients, and mixed-type RMS in six patients. Conventional MRI was performed in all 27 patients, and high-resolution diffusion-weighted imaging was conducted in 25 patients. The tumor location, size, morphological features, signal intensity, texture, contrast enhancement characteristics, lymph node metastases, apparent diffusion coefficients (ADCs), and involvement of local soft tissues were independently assessed by two authors.

RESULTS

On MR imaging, sinonasal RMS appeared isointense on T1-weighted imaging in 21 cases (77.8%) and heterogeneously hyperintense on T2-weighted imaging in 18 patients (66.7%). After enhancement, the tumors were heterogeneously enhanced in 24 cases (88.9%). Botryoid enhancement with multiple small rings resembling bunches of grapes was found in 15 cases (55.6%). Mucosal invasion of the maxillary sinus was identified in 51.9% patients. Skull and orbit involvement were found in 55.6% and 81.5% patients, respectively. Lymph node metastasis was seen in 18 cases (66.7%). There were significant differences in botryoid enhancement (P = 0.044) and skull involvement (P = 0.044) among different histological subtypes. The mean ADC value of RMS was 0.73 ± 0.082 × 10^-3 mm²/s, and there was no significant difference among different histological subtypes.

CONCLUSIONS

Some characteristic MRI findings such as botryoid enhancement in the ethmoid sinus, involvement of the orbit and skull, and a lower ADC value can provide important clues for preoperative diagnosis of sinonasal RMS in adults. Further, botryoid enhancement was more common in ERMS, while skull involvement was more common in ARMS.

Alveolar Rhabdomyosarcoma of the Nasal Dorsum of a Pediatric Patient: A Case Report

Alveolar rhabdomyosarcoma is a rare pediatric malignant tumor with a poor prognosis, and it is exceedingly rare for this tumor to manifest on the skin of the nasal dorsum. Therefore, timely and accurate treatment can improve the survival rate of patients. We reported a case of a 4 year-old child with acinar rhabdomyosarcoma of the nasal dorsum, and the patient was cured by surgery and postoperative chemotherapy without recurrence. This case report contributes to the understanding of this rare tumor.

Sphenoid sinus anatomical variants and pathologies: pictorial essay

The sphenoid sinus (SS) is one of the four paired paranasal sinuses (PNSs) within the sphenoid bone body. Isolated pathologies of sphenoid sinus are uncommon. The patient may have various presentations like headache, nasal discharge, post nasal drip, or non-specific symptoms. Although rare, potential complications of sphenoidal sinusitis can range from mucocele to skull base or cavernous sinus involvement, or cranial neuropathy. Primary tumors are rare and adjoining tumors secondarily invading the sphenoid sinus is seen. Multidetector computed tomography (CT) scan and magnetic resonance imaging (MRI) are the primary imaging modalities used to diagnose various forms of sphenoid sinus lesions and complications. We have compiled anatomic variants and various pathologies affecting sphenoid sinus lesions in this article.

Multimodality imaging evaluation of nasal sinus alveolar rhabdomyosarcoma: Two case reports

BACKGROUND

Rhabdomyosarcoma (RMS) is a common pleomorphic malignant soft tissue sarcoma in children and adolescents that originates from rhabdomyoblasts or mesenchymal precursor cells. Alveolar rhabdomyosarcoma (ARMS) mostly occurs in adolescents aged 10-15 years and is characterized by more aggressive behaviors and worse prognosis than other sarcomas, prone to lymphatic and hematogenous metastasis in the early stage as well as metastasizing to breast, testis, pancreas, and other parts. ARMS often occurs in the limbs and genitourinary system, however, head and neck ARMS are relatively rare when involving the nasal cavity or sinuses. The role of MRI and 18F-FDG positron emission tomography combined with computed tomography (PET/CT) remains to be established in ARMS.

CASE REPORT

Case 1: An 18-year-old male was found with a left submandibular mass of approximately 1 cm in diameter 2 months ago, which gradually increased in size. CT showed multiple soft tissue masses in maxillofacial and neck regions and the lesions invaded the frontal lobe and the inner wall of the left orbital lobe. MRI showed the masses with hypointensity on T1WI, hyperintensity on T2WI, and diffusion-weighted imaging (DWI) with significant enhancement. 18F-FDG PET/CT showed multiple hypermetabolic lesions located in the maxillofacial, neck region, 3rd lumbar vertebra, and the right sacrum. A nasal endoscopic tumor biopsy and molecular testing finally helped to diagnose the ARMS. Case 2: A 14-year-old male presented with left maxillary pain with nasal congestion and left ocular swelling 15 days ago. CT demonstrated a soft tissue mass in the nasal cavity and sinuses with local protrusion into the left orbit. MRI showed the masses with a slightly low signal on T1WI, a high signal on T2WI, and DWI with significant heterogenous enhancement. 18F-FDG PET/CT showed hypermetabolic lesions in the left maxillofacial and neck regions. ARMS was finally diagnosed by a nasal endoscopic tumor biopsy and molecular testing. The patient had a recurrence of the lesion after chemotherapy and surgical resection and is currently undergoing radiation therapy.

CONCLUSION

Nasal sinus ARMS is highly malignant with a poor prognosis. Accurate diagnosis relies not only on histopathology and immunohistochemistry examination but also on genetic detection of characteristic chromosomal translocations and fusion genes. Imaging methods, such as MRI and PET/CT can accurately assess the extent of the lesions and metastases, assist in the diagnosis of the disease and the selection of treatment regimens, provide precise localization for surgery, and help with treatment monitoring and follow-up.

Point-of-Care Ultrasound Assessment of Orbital Rhabdomyosarcoma in a Pediatric Patient

ABSTRACT

Rhabdomyosarcoma is the most common soft tissue tumor in children and orbital lesions account for 10% of these diagnoses. This case describes a young boy who presented with eyelid swelling that was initially concerning for an expanding hematoma given a history of recent trauma to the eye. Point-of-care ultrasound identified 2 distinct lesions surrounding the globe, which prompted further investigation, including ophthalmology consult and computed tomography. The case presented highlights the initial misdiagnosis on both point-of-care ultrasound and computed tomography and the importance of using color Doppler on ultrasound to distinguish an orbital rhabdomyosarcoma from a posttraumatic hematoma.

Non-orbital Sclerosing Rhabdomyosarcoma Presented With Optic Neuropathy

Sclerosing rhabdomyosarcoma presentations are widely variable and non-specific initial features. We report a rare case of non-orbital sclerosing rhabdomyosarcoma presented with optic neuropathy. A 15-year-old female patient initially presented with upper gum swelling and pain for 3 months. It was associated with loosening of teeth. Subsequently, the patient developed recurrent epistaxis follow by left facial swelling and blurring of vision. Examination showed marked left facial swelling with mild proptosis. Visual acuity in the left eye was no perception of light with the presence of relative afferent pupillary defect. Fundoscopy showed left optic atrophy. Neuroimaging showed large aggressive soft tissue mass on the left infratemporal, masticator, and parapharyngeal space with a local extension to the sphenoid sinus. There was also an intracranial extension to the left temporal lobe with the base of skull bone destruction. Transnasal endoscopic biopsy revealed sclerosing rhabdomyosarcoma. Management was with chemotherapy. Sclerosing rhabdomyosarcoma may present with optic nerve involvement that may carry a guarded prognosis to the eyes.

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.

MRI of Sinonasal Malignancies

ABSTRACT

Sinonasal cavity is an important subsite in head and neck tumors. There are a myriad of malignancies that present within this area. Adequate staging for treatment planning requires multimodality evaluation. Magnetic resonance imaging (MRI) forms an important component in the evaluation of sinonasal tumors. We sought to review the most common sinonasal tumors, including sinonasal anatomy, clinical features, and common imaging features. A literature review was performed to evaluate common sinonasal tumors. Owing to the different tissue types within the sinonasal cavity, there are multiple different tumor pathologies within the sinonasal compartment. Most present in adults although some present in the young. Many of these tumor types have imaging overlaps, although some have a characteristic appearance. MRI can aid in soft tissue delineation, evaluation of multicompartmental extension, intracranial spread, and perineural spread. Sinonasal tumors are a heterogeneous group for which soft tissue delineation via MRI forms an important role in ensuring adequate treatment planning to improve outcomes, decreasing morbidity, and improve functional outcomes.

MRI features of different types of sinonasan rhabdomyosarcomas: a series of eleven cases

OBJECTIVE

To retrospectively analyze magnetic resonance imaging (MRI) features of various pathological subtypes of sinonasal rhabdomyosarcoma (RMS) and explore correlations between imaging features and pathological subtypes.

METHODS

In total, 11 cases with embryonal, alveolar or pleomorphic sinonasal RMSs, confirmed by surgical pathology, were selected. Their characteristics and distinctive imaging features were analysed, and the correlation between pathology and imaging features was explored.

RESULTS

Bone destruction was observed in all 11 cases with RMS. Expansive growth was predominant in three alveolar and three embryonal RMS cases, and creeping growth was predominant in two alveolar, two embryonal and one pleomorphic RMS cases. Signs of residual mucosa were observed in all 11 cases, and 10 cases showed involvement of multiple sinus cavities and orbital cavities. All cases exhibited mild-to-intermediate enhancement.

CONCLUSION

Sinonasal RMSs have the following characteristic MRI features: ethmoid sinuses and middle nasal conchae are the prevalent sites; lesions are mainly of mild enhancement; tumours exhibit signs of residual mucosa, mild-to-intermediate enhancement and frequent orbital involvement; bone invasion and bone destruction are frequently observed; and haematogenous metastasis is not as common as lymphatic metastasis. RMSs of various pathological subtypes were not significantly distinct by imaging.

Li-Fraumeni Syndrome and Whole-Body MRI Screening: Screening Guidelines, Imaging Features, and Impact on Patient Management

OBJECTIVE

Li-Fraumeni syndrome (LFS) is a rare autosomal-dominant inherited syndrome containing a germline mutation in the TP53 gene, which predisposes to oncogenesis. Leukemia and tumors of the brain, soft tissues, breasts, adrenal glands, and bone are the most common cancers associated with this syndrome. Patients with LFS are very susceptible to radiation, therefore the use of whole-body MRI is recommended for regular cancer screening. It is important to recognize the common tumors associated with LFS on MRI, and it is also important to be aware of the high rate of false-positive lesions.

CONCLUSION

Whole-body MRI is useful for the detection of cancer in patients who come for regular screening; however, it is associated with pitfalls about which the radiologist must remain aware.

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.

Significance of MRI in the diagnosis and differentiation of clear cell sarcoma of tendon and aponeurosis (CCSTA): A case report

RATIONALE

Clear cell sarcoma of tendon and aponeurosis (CCSTA) or soft parts is a rare malignant melanin producing tumor entity that is derived from the neural crest cells originating from soft tissues displaying melanocytic differentiation. Diagnosis of CCSTA is difficult as it is dependent on age, size, location, necrosis, calcifications, cystic degeneration, and local to distant metastatic deposits. These tumors have very poor prognosis with a survival rate of 5-10 years because of local recurrence, early to late metastasis to lymph nodes, lungs, bones, and liver.

PATIENT CONCERNS

A 30-year-old Asian male has presented with a painful mass in the posterior aspect of the right ankle. He recalled of noticing an increase in the size of the lump after a traumatic insult 3 months ago. Physical examination revealed a mass of size 9x4 cm in the posterior ankle with no cutaneous ulcerative lesions. There is no history of any longstanding illness or malignancy.

DIAGNOSES

Clear cell Sarcoma of Tendon and Aponeurosis (CCSTA) or CCS of Soft parts.

INTERVENTIONS

Conventional radiography demonstrated merely a soft tissue mass in the posterior compartment of the right ankle and significant calcaneal bone erosion with the sparse trabecular pattern. Plain conventional tomography showed a well-defined soft tissue heterogeneous mass with a hypoattenuating osteo-destructive focal lesion in the calcaneus. Magnetic resonance imaging (MRI) - T1 weighted imaging (T1WI) revealed an iso-intense signal relative to adjacent muscle; heterogeneous high-signal intensity on fat saturated T2 weighted imaging (T2WI). On contrast examination, lesion on T1WI, showed a heterogeneous high signal intensity, central low signal intensity with peripheral and septal enhancement. The immune-histochemistry analysis was positive for HMB-45, S-100, myoD1 and Ki67 (30%). Correlating with imaging and immune-histochemistry, a confirmatory diagnosis of CCSTA was made.

OUTCOMES

CCSTA is typically a slowly growing painless mass in the deep soft tissues of ear, pancreas, kidney, penis, abdomen, especially in the lower extremities- Achilles tendon and aponeurosis of the ankle or in foot of young adults. As, these tumors are highly malignant, difficult to diagnose, early recognition by imaging and surgical excision are the mainstay of management.

LESSONS

Our case emphasizes the importance of recognizing radiological characteristics of CCSTA, and its differentiation from other soft tissue tumors, when presenting atypically. MRI plays a significant role in the diagnosis supported by histopathology and immune-histochemistry. So, radiologists should be familiar about this presentation that could guide other personnel for early detection of soft tissue tumors while including CCSTA into differential diagnosis for evaluation.

Prosthetic rehabilitation for a patient treated for embryonal rhabdomyosarcoma

A female patient, now aged 17 years, was diagnosed with rhabdomyosarcoma (RMS) in the right pterygopalatine fossa when she was 3 years old. The RMS was successfully treated by excision, but the subsequent radiation and polychemotherapy resulted in the complete anesthesia of the distribution area of the right trigeminal nerve and loss of vision in the right eye. The patient also experienced pain in the mandibular joints and masticatory muscles. Panoramic radiographs displayed a multiple agenesia of the permanent teeth and underdeveloped apices. Treatment involved the fabrication of a complete maxillary denture. A removable device was fabricated to evaluate her response to an occlusal vertical dimension increase of 6 mm and provide a stable intercuspal position. After wearing the prosthesis for 6 months, the patient reported that she was completely free of symptoms.

Imaging Characteristics of Malignant Sinonasal Tumors

Malignancies of the nasal cavity and paranasal sinuses account for 1% of all malignancies and 3% of malignancies of the upper aerodigestive tract. In the sinonasal tract, nearly half of all malignancies arise in the nasal cavity, whereas most of the remaining malignancies arise in the maxillary or ethmoid sinus. Squamous cell carcinoma is the most common histological subtype of malignant tumors occurring in this area, followed by other epithelial carcinomas, lymphomas, and malignant soft tissue tumors. Although many of these tumors present with nonspecific symptoms, each tumor exhibits characteristic imaging features. Although complex anatomy and various normal variants of the sinonasal tract cause difficulty in identifying the origin and extension of large sinonasal tumors, the invasion of vital structures such as the brain, optic nerves, and internal carotid artery affects patients’ prognosis. Thus, diagnostic imaging plays a key role in predicting the histological subtype and in evaluating a tumor extension into adjacent structures. This article describes the computed tomography and magnetic resonance imaging findings for malignant sinonasal tumors.

Head and neck rhabdomyosarcoma in children: a 20-year retrospective study at a tertiary referral center

OBJECTIVE

The purpose of this study was to assess rhabdomyosarcomas (RMS) of the head and neck in pediatric patients with regard to clinical presentation, treatment, and survival.

METHODS

Data were retrospectively obtained from patient charts with regard to RMS of the head and neck diagnosed between 1996 and 2016 at a tertiary referral center. Clinical course, treatment modalities, and side effects were analyzed. Survival analysis was carried out using the Kaplan-Meier method.

RESULTS

Twenty-eight patients (17 male, 11 female) with a mean age at diagnosis of 6.8 ± 5.0 years have been included. Fourteen patients (50%) presented with painless swelling in the head and neck region and nine patients (32.1%) presented with cranial nerve deficit at initial diagnosis. The location of the majority of rhabdomyosarcomas was orbital (N = 9; 32.1%), followed by parapharyngeal (n = 4; 14.2%) and sinonasal (n = 3; 10.7%). All patients (n = 28; 100%) received polychemotherapy, additional adjuvant radiation therapy was carried out in 24 patients (85.7%), and surgery was performed in 12 cases (42.9%). The 5-year overall survival was 91.3%, and median progression-free survival was 46 ± 67.4 months. Common side effects resulting from chemotherapy and radiation therapy included neutropenia, mucositis, nausea and vomiting, and radiodermatitis, long-term side effects included microsomia and facial mutilation.

CONCLUSION

Multimodality treatment of rhabdomyosarcomas of the head and neck in pediatric patients may lead to a 5-year overall survival of up to 91.3%.

Multiparametric MRI findings of sinonasal rhabdomyosarcoma in adults with comparison to carcinoma

PURPOSE

To identify magnetic resonance imaging (MRI) features of sinonasal rhabdomyosarcoma in adults, including diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI features as compared with carcinomas.

MATERIALS AND METHODS

Sixty-four patients were included in this study, including 12 sinonasal rhabdomyosarcomas and 52 sinonasal carcinomas. MRI was completed in all 64 patients with a 3T MR scanner. Conventional MR (nonenhanced and static contrast-enhanced) imaging features, DCE-MRI parameters, and the apparent diffusion coefficients (ADCs) were analyzed by two authors independently (X.Y.W. and Y.Z.W.).

RESULTS

Compared with gray matter, sinonasal rhabdomyosarcomas appeared isointense on T₁ -weighted images in 11 cases (91.7%, 11 of 12), and hyperintense on T₂ -weighted images in 9 patients (75%, 9 of 12). After contrast, sinonasal rhabdomyosarcomas showed inhomogeneous enhancement in 10 cases (83.3%, 10 of 12). Skull involvement was found in eight patients (66.7%) with rhabdomyosarcomas. On T₂ -weighted images, sinonasal carcinomas demonstrated isointense in 31 cases (59.6%, 31/52), hyperintense in 14 (26.9%, 14/52), and hypointense in 7 (13.5%, 7/52). Skull involvement was detected in 14 cases (14/52, 26.9%). There were significant differences in T₂ signal intensity (P = 0.005) and skull involvement (P = 0.016) between sinonasal rhabdomyosarcoma and carcinomas. There was a marginal difference in time to peak enhancement (P = 0.061), while no difference in time to maximum enhancement (P = 0.403), maximum contrast index (P = 0.368), and time-intensity curve types (P = 0.138) between rhabdomyosarcoma and carcinomas. The ADCs of sinonasal rhabdomyosarcoma were significantly lower than those of sinonasal carcinomas (P < 0.001).

CONCLUSION

A multiparametric approach using conventional MRI with added ADCs had the potential to improve the diagnostic accuracy of sinonasal rhabdomyosarcoma in adults. Evidence level: 4 J. Magn. Reson. Imaging 2017;45:998-1004.

Head and neck rhabdomyosarcoma: follow-up results of four cases and review of the literature

Head and neck rhabdomyosarcoma (HNRMS) is exceedingly rare and poorly documented. The difficult diagnosis often causes a poor prognosis and high mortality. Hence, we report 4 cases of HNRMS and their follow-up outcomes, and review the clinicopathological features of this rare tumor. The 4 patients ranged in age from 5 to 29 years. Among them, 3 patients had a good prognosis after combination of radiotherapy and chemotherapy or surgery alone. Another patient survived for only 3 months after diagnosis without therapy. Deeply insight into HNRMS might improve the ability of diagnosis and treatment for this disease.