Orbital rhabdomyosarcoma--the radiological characteristics

Receptor tyrosine kinase gene expression profiling of orbital rhabdomyosarcoma unveils MET as a potential biomarker and therapeutic target

Receptor tyrosine kinases (RTKs) serve as molecular targets for the development of novel personalized therapies in many malignancies. In the present study, expression pattern of receptor tyrosine kinases and its clinical significance in orbital RMS has been explored. Eighteen patients with histopathologically confirmed orbital RMS formed part of this study. Comprehensive q-PCR gene expression profiles of 19 RTKs were generated in the cases and controls. The patients were followed up for 59.53 ± 20.93 years. Clustering and statistical analysis tools were applied to identify the significant combination of RTKs associated with orbital rhabdomyosarcoma patients. mRNA overexpression of RTKs which included MET, AXL, EGFR was seen in 60-80% of cases; EGFR3, IGFR2, FGFR1, RET, PDGFR1, VEGFR2, PDGFR2 in 30-60% of cases; and EGFR4, FGFR3,VEGFR3 and ROS,IGFR1, EGFR1, FGFR2, VEGFR1 in 10-30% of cases. Immunoexpression of MET was seen in 89% of cases. A significant association was seen between MET mRNA and its protein expression. In all the cases MET gene expression was associated with worst overall survival (P = 0.03).There was a significant correlation of MET mRNA expression with RET, ROS, AXL, FGFR1, FGFR3, PDGFR1, IGFR1, VEGFR2, and EGFR3 genes. Association between MET gene and collective expression of RTKs was further evaluated by semi-supervised gene cluster analysis and Principal component analysis, which showed well-separated tumor clusters. MET gene overexpression could be a useful biomarker for identifying high risk orbital rhabdomyosarcoma patients. Well-separated tumor clusters confirmed the association between MET gene and collective expression of RTK genes. Therefore, the therapeutic potential of multi-kinase inhibitors targeting MET and the 9 other significant RTKs needs to be explored.

Orbital rhabdomyosarcoma in children

Purpose. To analyze the results of treatment and active monitoring the children with orbital rhabdomyosarcoma (RMS) with an emphasis on vital prognosis. Material and methods. We examined 32 children with RMS (18 boys, 14 girls) aged 2 months to 12 years, whose case history ranged from 1 week to 16 weeks (median, 5 weeks). The median follow-up was 60 months. The tumor was localized in the upper (n = 13), upper internal (n = 9), lower (n = 4), internal (n = 3), and external (n = 3) quadrants. The patients underwent primary surgical treatment: orbitotomy using transcutaneous (n = 26), transconjunctival (n = 2) and subperiosteal access (n = 4) followed by cytological, histological and immunohistochemical tissue verification in all cases. Results. The highest number of RMS cases was noted in in the 2- to 7-year-old group (66 % of patients). All patients were treated in in-patient settings. Complete macroscopic removal of tumor was performed in 17 cases, partial removal in 9 cases, and biopsy sampling in 6 cases. The embryonic type of RMS accounted for 87 % (n = 28), and the alveolar type, for 13 % (n = 6). In the postoperative period all children received combined therapy (systemic polychemotherapy and distant radiation therapy) in in-patient facilities of special oncological and radiological clinics. The survival rate of the whole group was 100%. In the long-term follow-up period (after 3 to 5 years), reconstructive surgeries were performed to correct ptosis and strabismus, and/or spectacle or prismatic correction of complex or mixed astigmatism. In cases of “dry” eye syndrome, conservative local therapy was offered. After orbital exenteration, ectoprosthesis procedures was applied. Conclusion. The analysis of our observations of 32 children with orbital rhabdomyosarcoma showed a 100 % survival rate, which testifies to the importance of timely diagnosis and combined treatment of the tumor.

Rare neonatal malignant primary orbital tumors: Three case reports

BACKGROUND

Aggressive malignant primary orbital tumors are extremely rare in newborns. The current cases further clarify the clinical features of malignant primary orbital tumors in neonates.

CASE SUMMARY

At the time of presentation at the Seventh Center of People’s Liberation Army General (PLAG) Hospital, the children were 1-, 2- and 5-mo-old, respectively, and included 2 boys and 1 girl. All three cases had unilateral proptosis at birth, and underwent mass excision and histopathologic examination. A peripheral primary neuroectodermal tumor, an aggressive infantile fibromatosis and an embryonic rhabdomyosarcoma were diagnosed, respectively. The first case underwent routine chemotherapy following surgery but died within three months due to worsening condition as the tumor spread throughout the body. The other two children were treated by surgery, and at the follow-up visits 6 mo and 1 year after surgery, respectively, the wound was completed healed, and they had normal growth and development without radiotherapy or chemotherapy. A review of highly uncommon orbital tumors in newborns is also provided.

CONCLUSION

Malignant primary tumors should be considered in the presence of unilateral proptosis in newborns.

Adult rhabdomyosarcoma originating in the temporal muscle, invading the skull and meninges: A case report

BACKGROUND

Rhabdomyosarcoma (RMS) is a rare malignant tumor of mesenchymal origin that mainly affects children. Spindle cell/sclerosing RMS (SSRMS) is even rarer. It is a new subtype that was added to the World Health Organization disease classification in 2013. To the best of our knowledge, this is the first reported case of adult SSRMS disease classification originating in the temporal muscle.

CASE SUMMARY

SSRMS originating in the temporal muscle of a male adult enlarged rapidly, destroyed the skull, and invaded the meninges. The tumor was completely removed, and the postoperative pathological diagnosis was SSRMS. Postoperative recovery was good and chemotherapy and radiotherapy were given after the operation. Followed up for 3 mo, no tumor recurred.

CONCLUSION

RMS is one of the differential diagnoses for head soft tissue tumors with short-term enlargement and skull infiltration. Preoperative computed tomography or magnetic resonance imaging is necessary for early detection of tumor invasion of the skull and brain tissue.

Etiologies of Proptosis: A review

Proptosis, the protrusion of the eyeball from the orbit, results from a wide variety of pathologies that can be vision- or life-threatening. Clinical history, associated physical exam findings, and imaging features are all crucial in establishing the underlying etiology. The differential diagnosis is broad, and includes infectious, inflammatory, vascular, and neoplastic entities that range from benign and indolent, to malignant and aggressive. While treatment varies significantly based on the disease process, all are aimed at preserving vision, salvaging the globe, preventing disfigurement, and reducing mortality. Both internists and general ophthalmologists should be familiar with the causes of proptosis in order to initiate the work-up for, and appropriately triage, affected patients.

Genetic profiling of rhabdomyosarcoma with clinicopathological and radiological correlation

OBJECTIVE

Orbital Rhabdomyosarcoma is a highly malignant tumor predominantly affecting children. Our study adds more understanding of this tumor to ophthalmologists from the clinicopathological, radiological and genetic aspects.

DESIGN

A retrospective clinicopathological and radiological study of ocular rhabdomyosarcoma with genetic profiling.

PARTICIPANTS

All the cases with confirmed tissue diagnosis of orbital rhabdomyosarcoma presenting at a tertiary eye hospital in Riyadh, Saudi Arabia during the period 1985-2015.

METHODS

Charts and histological slides of 26 patients were reviewed. DNA was extracted from paraffin-embedded biopsies and genotyping was performed to detect chromosomal abnormalities and Copy-number variations regions.

RESULTS

18 males and 8 females were included with a mean age at presentation of 6.9 years (SD of 4.4). Proptosis and globe displacement were the commonest clinical presentations. Embryonal histopathological type was the commonest (73.1%) with superior orbital involvement (p = 0.024). Using magnetic resonance imaging, the embryonal type showed higher Apparent diffusion coefficient (ADC) value compared to the alveolar type (p = 0.98). Genetic profiling showed Copy-number gain in regions spanning PAX3, DDIT3, Gli, Wnt6 genes. DICER1 gene implication was found in 9 sporadic cases.

CONCLUSION

Rhabdomyosarcoma is rare and occurs with a mean age of 7 years, predominantly among males. The commonest embryonal type is significantly correlated with superior orbital involvement. Radiologically, it shows an ADC of 0.67-0.09 × 10^-3mm²/s. (p = 0.98). The gain in PAX3, DDIT3, Gli1, Wnt6 genes is a new finding while the DICER1 gene implication in the absence of familial hereditary carcinoma is another interesting finding.

Imaging of orbital disorders

Diseases of the orbit can be categorized in many ways, but in this chapter we shall group them according to etiology. Inflammatory diseases of the orbits may be infectious or noninfectious. Of the infections, orbital cellulitis is the most common and typically arises as a complication of acute sinusitis. Of the noninfectious, inflammatory conditions, thyroid orbitopathy is the most common and results in enlargement of the extraocular muscles and proliferation of the orbital fat. Idiopathic orbital inflammatory syndrome is another cause of inflammation in the orbit, which may mimic thyroid orbitopathy or even neoplasm, but typically presents with pain. Masses in the orbit may be benign or malignant and the differential diagnosis primarily depends on the location of the mass lesion, and on the age of the patient. Lacrimal gland tumors may be lymphomas or epithelial lesions of salivary origin. Extraocular muscle tumors may represent lymphoma or metastases. Tumors of the intraconal fat are often benign, typically hemangiomas or schwannomas. Finally, globe tumors may be retinoblastomas (in children), or choroidal melanomas or metastases in adults.

Clinical Management of Orbital Rhabdomyosarcoma in a Referral Center in Spain

PURPOSE

To review the systemic and ocular outcomes and long-term status of ocular rhabdomyosarcoma in pediatric patients in a tertiary center in Spain.

METHODS

All patients younger than 18 years who were diagnosed as having ocular rhabdomyosarcoma and treated between 1982 and 2011 at La Paz University Hospital, Madrid, Spain, were included. Clinical presentation, management, complications, and ocular and systemic outcomes were reviewed.

RESULTS

The mean age at presentation was 8 years (range: 3 months to 12.5 years). In all cases, the rhabdomyosarcoma was located primarily in the orbit. Treatment included surgical debulking and various regimens of chemotherapy and radiotherapy. All of the patients underwent surgical biopsy for diagnosis confirmation. Orbital exenteration was performed in 4 cases (28%). Twelve patients received radiotherapy. The long-term visual outcomes of the 10 patients who maintained their globe was as follows: best corrected visual acuity 20/20 to 20/40 in 6 patients (60%), 20/50 to 20/100 in 2 patients (20%), and 20/200 to no light perception in 2 patients (20%). Intraocular complications (primarily cataracts: 50%) were present in 7 patients (70%), ocular surface lesions occurred in 6 patients (60%), and orbital sequelae were found in 8 patients (80%). Local tumor recurrence was detected in 5 patients (35%) and distant metastasis occurred in 2 patients (14%). Tumor-related death occurred in 1 patient (7%).

CONCLUSIONS

Orbital rhabdomyosarcoma has an excellent prognosis; nevertheless, local complications are common, including surgery-related complications. To minimize them, initial surgical planning based on individual patient characteristics and an accurate diagnosis of relapses is mandatory. The clinical presentation, management, and long-term ocular and systemic outcomes are comparable with other series published to date.

Destruction of the craniofacial skeleton in the child caused by an orbital tumor

PURPOSE

The aims of this paper are to describe the morphological alterations within an infant craniofacial skeleton caused by an orbital tumor and present how the bone reacts in contact with a spreading tumor mass.

METHODS

A study was performed on the dry skull of a child at the age of approximately 2 years. Morphological alterations of the craniofacial skeleton were analysed by visual inspection, and the intracranial cavity was examined with the aid of a digital camera. Subsequently, the skull was examined using computed tomography.

RESULTS

The skull was identified as having unilateral symptoms of orbital destruction caused by a malignant tumor, probably retinoblastoma or rhabdomyosarcoma. The left orbit and surrounding bones showed extensive malformation caused by the invading tumor. Profound deformities were also observed in the nasal cavity, which was partially occluded by the collapsed medial wall of the left orbit. The tumor extended to the wall of the orbit, spread out of the orbit, penetrated to the anterior cranial fossa, and probably invaded the brain.

CONCLUSIONS

Extensive pathological cranial destruction and possible metastases to inner organs suggest that the orbital tumor was the cause of death. Anatomical alterations observed in the craniofacial skeleton indicate a highly aggressive character of the orbital tumor.

Orbital rhabdomyosarcomas: A review

Rhabdomyosarcoma (RMS) is a highly malignant tumor and is one of the few life-threatening diseases that present first to the ophthalmologist. It is the most common soft-tissue sarcoma of the head and neck in childhood with 10% of all cases occurring in the orbit. RMS has been reported from birth to the seventh decade, with the majority of cases presenting in early childhood. Survival has changed drastically over the years, from 30% in the 1960's to 90% presently, with the advent of new diagnostic and therapeutic modalities. The purpose of this review is to provide a general overview of primary orbital RMS derived from a literature search of material published over the last 10 years, as well as to present two representative cases of patients that have been managed at our institute.

Orbital masses: CT and MRI of common vascular lesions, benign tumors, and malignancies

A wide variety of space occupying lesions may be encountered in the orbit. CT and MR imaging frequently help confirm the presence of a mass and define its extent. Characteristic imaging features may help distinguish among lesions that have overlapping clinical presentations. This review focuses on some of the common orbital masses. Common vascular lesions that are reviewed include: capillary (infantile) hemangioma, cavernous hemangioma (solitary encapsulated venous-lymphatic malformation), and lymphangioma (venous-lymphatic malformation). Benign tumors that are reviewed include: optic nerve sheath meningioma, schwannoma, and neurofibroma. Malignancies that are reviewed include: lymphoma, metastasis, rhabdomyosarcoma, and optic glioma. Key imaging features that guide radiological diagnosis are discussed and illustrated.

Undifferentiated sarcoma of the sellar region

Malignancies lacking specific features of cellular maturation are termed "undifferentiated" and represent 5-10% of all human tumors. They are encountered at a variety of sites but do not, as a rule, arise in the sellar region. A 39-year-old male with a history of testicular seminoma and an unsuccessful biopsy of a third ventricular neoplasm, presented with visual disturbances and memory loss. Light microscopically, the tumor consisted entirely of undifferentiated spindle cells. No germ cell component was noted. An exhaustive immunohistochemical study found immunoreactivity for vimentin and desmin, but for no other myoid markers. Polymerase chain reaction showed no X;18 translocation. Based upon these studies, a diagnosis of "undifferentiated sarcoma" was made. Our case, being highly unusual among reported sellar neoplasms, underscores the difficulties inherent in the differential diagnosis of undifferentiated neoplasms.

Neuroimaging in neuro-ophthalmology

The modern imaging era has introduced a variety of techniques that aid in the evaluation of complex neurologic problems. To optimize the yield of neuroimaging the clinician must, first and foremost, determine the nature of the neuro-ophthalmic disorder; and then localize the lesion. Once the localization of the neuro-ophthalmic problem is understood, the optimal imaging modality can be directed toward the anatomic region of interest. In this article the approach to neuroimaging is discussed, with emphasis on the anatomic localization of lesions affecting afferent and efferent visual function.

Imaging findings in craniofacial childhood rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the commonest paediatric soft-tissue sarcoma constituting 3-5% of all malignancies in childhood. RMS has a predilection for the head and neck area and tumours in this location account for 40% of all childhood RMS cases. In this review we address the clinical and imaging presentations of craniofacial RMS, discuss the most appropriate imaging techniques, present characteristic imaging features and offer an overview of differential diagnostic considerations. Post-treatment changes will be briefly addressed.

Extraconal orbital tumors in children--a spectrum

Orbital masses in children are uncommon but extremely challenging problems for clinicians and pathologists due to their critical location and availability of limited diagnostic material. We analyzed 47 specimens comprising biopsies, excision specimens, and FNAC of extraconal pediatric orbital masses (excluding retinoblastoma) accessioned in the pathology department over 5 years in a tertiary referral cancer center. Immunohistochemistry (IHC-74%) and molecular methods (one case) were done where necessary. The chief presenting symptom was proptosis in 55.3% patients and radiologically 53.8% malignant tumors showed extraorbital extension. A diagnostic algorithm was formulated to assess which cases needed pathology evaluation. Malignant round cell tumors (76.6%), chiefly embryonal rhabdomyosarcoma (51%), benign spindle cell neoplasms, and infectious lesions (tuberculosis, fungal infections), were seen. Of the malignant tumors, those confined to the orbit achieved good treatment response and had an event-free follow-up while those with extraorbital spread had poor outcome. Pediatric orbital masses range from completely treatable infectious lesions, surgically resectable benign neoplasms to aggressive malignancies requiring chemotherapy and radiotherapy. Pathologists play a key role in distinguishing these on small biopsy material and expediating accurate treatment thus saving the vision or life of a patient.

The role of radiology in paediatric soft tissue sarcomas

Paediatric soft tissue sarcomas (STS) are a group of malignant tumours that originate from primitive mesenchymal tissue and account for 7% of all childhood tumours. Rhabdomyosarcomas (RMS) and undifferentiated sarcomas account for approximately 50% of soft tissue sarcomas in children and non-rhabdomyomatous soft tissue sarcomas (NRSTS) the remainder. The prognosis and biology of STS tumours vary greatly depending on the age of the patient, the primary site, tumour size, tumour invasiveness, histologic grade, depth of invasion, and extent of disease at diagnosis. Over recent years, there has been a marked improvement in survival rates in children and adolescents with soft tissue sarcoma and ongoing international studies continue to aim to improve these survival rates whilst attempting to reduce the morbidity associated with treatment. Radiology plays a crucial role in the initial diagnosis and staging of STS, in the long term follow-up and in the assessment of many treatment related complications. We review the epidemiology, histology, clinical presentation, staging and prognosis of soft tissue sarcomas and discuss the role of radiology in their management.

An intrasellar rhabdomyosarcoma misdiagnosed as pituitary adenoma

BACKGROUND

Rhabdomyosarcoma is a malignant tumor of the skeletal muscle cells. Those tumors mainly affect children and arise in primitive fetal mesenchyme even at sites that do not contain skeletal muscle. However, very few intracranial rhabdomyosarcomas have been reported. No previous case of primary intrasellar rhabdomyosarcoma except for 1 case has been reported in the literature.

CASE DESCRIPTION

A 44-year-old woman presented with fatigue and diplopia associated with amenorrhea and galactorrhea. Visual field evaluation revealed a superior temporal deficit in both eyes. A right afferent pupillary defect was present. Magnetic resonance imaging revealed an intrasellar tumor with suprasellar extension. The tumor involved the sella turcica and right cavernous sinus. The patient was preoperatively diagnosed as pituitary adenoma, which was confirmed pathologically as rhabdomyosarcoma after the operation.

CONCLUSIONS

Our findings suggest that rhabdomyosarcoma should be considered in the differential diagnosis of a primary intrasellar neoplasm.

Orbital rhabdomyosarcoma

BACKGROUND

Although rhabdomyosarcoma (RMS) is a rare tumor among the entire group of mesenchymal malignancies, it is a relatively common lesion and significant challenge for the ocular oncologist in terms of its diagnosis and management.

METHODS

A comprehensive literature search of articles published over the past 30 years in PubMed was conducted.

RESULTS

Orbital RMS usually presents as a space-occupying lesion in the orbit during the first decade and may mimic other neoplastic or inflammatory masses. The tumor has predilection for the superior nasal quadrant of the orbit. The clinical manifestations depend on the location of the tumor within the orbit and its rate of growth. The common histopathologic types are embryonal and alveolar varieties. CT and MR imaging are important in the evaluation of this tumor. Particular attention should be placed on the bone invasion and extension of the tumor into the intracranial cavity and paranasal sinuses. Treatment usually consists of a combination of chemotherapy and radiation therapy following excisional biopsy.

CONCLUSIONS

Survival of orbital RMS has improved due to advances in chemotherapy and radiotherapy. Posttreatment complications, including side effects of radiotherapy and secondary orbital malignancies, as well as visual dysfunction, occur more often and present new challenges due to improved long-term survival.

Use of 2-deoxy-2-[F-18]-fluoro-D-glucose positron emission tomography to monitor therapeutic response by rhabdomyosarcoma in children: report of a retrospective case study

PURPOSE

The purpose of this study was to study the use of 2-deoxy-2-[F-18]-fluoro-D-glucose positron emission tomography (F-18 FDG PET) for monitoring therapeutic response by rhabdomyosarcoma (RMSA) in children.

PATIENTS AND METHODS

A retrospective case study was performed by searching a computer database for the patients with RMSA in whom F-18 FDG PET studies were performed pre- and posttreatment. The data of the PET studies from these patients were analyzed in conjunction with clinical treatment and other imaging studies to determine whether interval changes of F-18 FDG uptake by the RMSA reflect response of RMSA to treatment.

RESULTS

Four patients with RMSA who received both pretreatment and posttreatment F-18 FDG PET studies were identified from the database and included in this study. A dramatic decrease of F-18 FDG uptake by the tumor was evident in the patients who had a favorable response to the therapy and prolonged remission of the disease. In contrast, persistent abnormal FDG uptake in one patient was associated with early relapse of the RMSA.

CONCLUSIONS

F-18 FDG PET may be useful for monitoring therapeutic response by RMSA in children, which needs to be verified with a prospective study in a larger patient population.

Imaging of the Lacrimal Gland

The lacrimal gland is situated superolateral to the eye and produces tears that moisten, lubricate, and protect the delicate corneal and conjunctival epithelium. Anatomically related to the orbit but embryologically and functionally more closely related to the salivary glands, radiological imaging has proven invaluable in delineation and differentiation of the unique range of pathological processes affecting the lacrimal gland. This article details traditional and new imaging techniques used in investigating such pathology and discusses the imaging findings and patterns of spread characteristic of various neoplastic, inflammatory, and structural processes ranging from benign adenomas, adenocarcinomas, and lymphomas to sarcoidosis, Mickulicz's syndrome, histiocytosis, and benign dacrocysts.

A case of alveolar rhabdomyosarcoma of the ethmoid sinus invading the orbit in an adult

Purpose

A case study and literature review of alveolar rhabdomyosarcoma (RMS) in an adult.

Methods

A 48-year-old male patient presented at our clinic complaining of proptosis that had persisted for 2 weeks in his left eye. A computed tomography (CT) scan revealed a destructive soft-tissue mass in the left ethmoid sinus with invasion of the left orbit and compression of the medial rectus muscle. Endoscopic intranasal biopsy revealed alveolar RMS. Conservative debulking and orbital wall decompression were performed.

Results

Immunohistochemical testing was positive for desmin, S-100, and smooth muscle actin (SMA), supporting the diagnosis of RMS. Since ipsilateral cervical and spinal metastasis was detected, systemic treatment was administered simultaneously.

Conclusions

Although rarely found in adults, RMS should be considered in the differential diagnosis of orbital tumors. Immunohistochemical analysis plays an important role in the definitive diagnosis of RMS.

Effectiveness of chemotherapy in rhabdomyosarcoma: example of orbital primary

The survival of patients with rhabdomyosarcoma has been progressively improved with successive protocols due to the development of multidisciplinary management and the data accumulated by international groups. Orbital rhabdomyosarcoma represents 10% of all cases and affects young children (median age: 6.8 years). It is a chemosensitive and radiosensitive tumour. Chemotherapy is designed to decrease the indications for local therapy (mainly radiotherapy) responsible for a high rate of sequelae (cosmetic, functional or secondary cancer). According to the International Society of Paediatric Oncology guidelines, local therapy is not indicated as first-line treatment in case of complete remission after chemotherapy. The 10-year survival of children with non-parameningeal orbital rhabdomyosarcoma is currently 87% and identical survivals are reported by the various collaborative groups despite the use of different treatments. Despite clinical trials demonstrating the efficacy of many types of chemotherapy (cisplatin, etoposide, doxorubicin, dacarbazine), the value of adding these drugs to combination chemotherapy comprising of an alkylating agent (cyclophosphamide or ifosfamide), vincristine and dactinomycin has not been formally demonstrated in terms of survival benefit for children with rhabdomyosarcoma. The authors review these various results and compare the current guidelines for the management of orbital rhabdomyosarcoma recommended by North American and European groups.

Orbital Rhabdomyosarcoma and Simulating Lesions

The appropriate diagnosis and treatment of orbital rhabdomyosarcoma requires close cooperation and communication between the radiologist, the ophthalmologist, and the medical and radiation oncologists. The clinical presentation, imaging characteristics, and staging of orbital rhabdomyosarcoma are discussed. A discussion of several important simulating lesions and their distinguishing characteristics follows.

Intraorbital and periorbital tumors in children--value of ultrasound and color Doppler imaging in the differential diagnosis

PURPOSE

To evaluate the role of ultrasonography (US) and color Doppler imaging (CDI) in the diagnosis of orbital tumors in children.

DESIGN

Retrospective nonrandomized interventional case series.

METHODS

This study included 42 children with intraorbital and periorbital tumors who were evaluated in our clinic. All children underwent a complete clinical evaluation as well as orbital US and CDI. The children then underwent operation or were followed up, based on the clinical diagnosis and the findings on the imaging modalities.

RESULTS

The mean age of the patients at diagnosis was 22.5 months (range 2 weeks-14 years old). Eighteen patients (12 female and 6 male) were diagnosed with hemangioma based on the findings in US and CDI; 16 patients (9 female and 7 male) were diagnosed with dermoid, 5 patients (4 female and 1 male) with lymphangioma, 2 patients with rhabdomyosarcoma, and 1 patient with a subperiostal abscess. Twenty-two patients underwent operation, and the diagnosis was confirmed on pathology. Twenty patients did not undergo operation and continued to be followed up in the clinic (mean follow-up period 38.2 months). The disease course in all patients who did not undergo operation was consistent with the working diagnosis.

CONCLUSION

Both US and CDI are useful modalities in the diagnosis of intraorbital and periorbital tumors in the pediatric age group.

Imaging of orbital disorders in pediatric patients

The spectrum of orbital lesions occurring in childhood is wide, including a variety of both benign and malignant disorders. Although physical examination and fundoscopy may aid in establishing the diagnosis of retro-ocular lesions, imaging remains a critical step in the evaluation of the pediatric orbit. Ultrasonography, CT, and MR imaging are the primary modalities for the evaluation of the diseased orbit, and careful observation of the characteristic radiological features usually leads to correct diagnosis; however, some of the lesions look very similar and are difficult to differentiate from each other. The purpose of this article is to review the common and unusual entities that may involve the pediatric orbit, to describe the radiological features, and to evaluate the efficacy of US, CT, and MRI in the diagnosis and management of these conditions.

Rhabdomyosarcoma: review for the ophthalmologist

Rhabdomyosarcoma is a malignant neoplasm that is composed of cells with histopathologic features of striated muscle in various stages of embryogenesis. It can occur in several sites in the body, including the ocular region. Ocular rhabdomyosarcoma is defined as the occurrence of this tumor in the area of the eye. Most ocular rhabdomyosarcomas arise in the soft tissues of the orbit but they can rarely occur in the other ocular adnexal structures and even within the eye. The purpose of this review is to provide a brief overview of rhabdomyosarcoma and a more detailed review of orbital rhabdomyosarcoma, with emphasis on changing concepts in the diagnosis and management of this ophthalmic neoplasm.

Localized paediatric orbital rhabdomyosarcoma: influence of imaging on treatment

AIM

Orbital rhabdomyosarcoma is the most common primary malignant orbital tumour in children and has a good prognosis. The purpose of this paper was to review the imaging and consequent treatment of patients with localized orbital rhabdomyosarcoma from around the U.K.

MATERIALS AND METHODS

Patients were identified through the U.K. Children's Cancer Study Group (UKCCSG) database. Investigations and therapy were dictated by the Malignant Mesenchymal Tumour '89 (MMT89) protocol. Imaging and radiological reports of 16 patients from 12 centres were reviewed. The number of patients receiving radiotherapy, timing of radiotherapy, and adherence to treatment protocols were assessed.

RESULTS

Local radiologists' reports and imaging techniques varied between sequential examinations and centres. The imaging was adequate for management. No reports quoted measurements of the tumours. Treatment protocols were not always followed rigidly with regard to a residual mass at day 80 post-diagnosis. However, the protocol was not explicit for all outcomes. Fifteen out of 16 patients eventually received radiotherapy.

CONCLUSION

There is no standardization of imaging between centres. The presence or absence of a post-therapeutic residue should be stated in the radiology report. Further investigation is needed to differentiate between fibrosis and recurrent tumour. Radiotherapy for residual mass at day 80 is probably more important than standardizing radiological technique.

Orbital rhabdomyosarcoma presenting as an apparent orbital subperiosteal abscess

We present a patient with acute sinusitis whose CT scan showed a ring-enhancing lesion within the orbit typical of an orbital subperiosteal abscess. On exploration of the orbit, there was no pus present but a tumour was found, which on histological examination was found to be a rhabdomyosarcoma. The clinical signs and CT characteristics of orbital subperiosteal abscesses and rhabdomyosarcomas are discussed. A ring-enhancing lesion within the orbit on CT scan should not be regarded as being pathognomonic for a subperiosteal abscess and the possibility of other diagnoses should be considered.