case 1 trilateral...

CASE 1 Trilateral retinoblastoma

Andreas Rauschecker and Heike E. Daldrup-Link

Imaging descriptionA two-year-old boy presented with leukocoria (¼ white pupil).Ophthalmoscopy demonstrated large masses in both globes.A CT scan showed extensive calcifications of both lesions(Fig. 1.1a). An MR scan better delineated the contrast-enhancing masses in the bilateral globes, both of which dem-onstrated extraocular extension (Fig. 1.1b).

An axial contrast-enhanced MR scan of the brain in adifferent patient with retinoblastoma shows an additional,inhomogeneously enhancing mass in the pineal gland(Fig. 1.2).

ImportanceRetinoblastoma is the most common intraocular tumor ofchildhood, occurring in one in 15000 to 20000 live births.Approximately 200 new cases a year are diagnosed in theUSA. The disease presents in infancy or early childhood,with the majority of cases diagnosed before the age of4 years.

A second primary malignancy, most commonly a midlineintracranial tumor, is found in 5–7% of patients with bilat-eral retinoblastoma. Often, these other brain tumors occurweeks or months after the diagnosis of the retinoblastoma,with a median interval of 21 months. Trilateral retinoblas-toma has traditionally been nearly universally fatal, althougha recent study suggests that intensive chemotherapy mayimprove survival. Early detection is likely an importantfactor in survival.

Typical clinical scenarioThe most frequent presenting sign of retinoblastoma is leuko-coria, a white papillary reflex. Other clinical presentationsinclude strabismus, decreased vision, orbital and/or periorbitalinflammation, glaucoma, hypopyon (tumor cells anterior tothe iris), or ocular pain. The genetic evolution of retinoblas-toma follows the Knudson’s two-hit hypothesis: patients whohave unilateral unifocal disease have mutations at the retino-blastoma locus in both alleles within a single retinal cell. Thisis an unlikely event; therefore, these tumors are usually uni-focal and unilateral, and are rarely associated with othertumors. By contrast, patients with multifocal and bilateralretinoblastomas harbor an underlying germ-line mutation thatresults in a mutant RB gene in every cell of their bodies. Loss ofheterozygosity and loss of the normal allele leads to the devel-opment of multiple retinoblastomas in one or both eyes. Thesepatients with germ-line mutations are predisposed to develop-ment of additional midline brain tumors and other non-oculartumors.

A trilateral retinoblastoma is the association of a midlineintracranial tumor with familial bilateral retinoblastoma,and has been reported in 6% of children with bilateral retino-blastoma and 10% of those with a family history of retino-blastoma. Classically, the intracranial tumor is located inthe pineal region and the most common tumor type is apinealoblastoma.

On CT scans, a retinoblastoma is recognized as a hyperat-tenuating intraocular mass, which contains punctate ornodular calcifications in over 90% of cases. The tumor maylead to retinal detachment, subretinal effusion, and/or vitrealhemorrhage.

On MR scans, retinoblastomas are hyperintense to vit-reous on T1-weighted and proton density-weightedimages, and show marked enhancement after contrastmedia injection. On T2-weighted MR images, retinoblas-tomas appear hypointense to adjacent vitreous. Possibleextension of the tumor beyond the sclera and along theoptic nerve is prognostically important, and needs to bereported.

Pineal gland tumors are delineated as inhomogeneous,contrast-enhancing soft tissue masses in the pineal region.Careful attention has to be paid to possible leptomeningealmetastases and spinal lesions. Of note, the normal pineal glanddoes not have a blood–brain barrier. Therefore, the presenceof contrast enhancement alone should not be confused with apineal gland mass.

Differential diagnosisStrongly T2-weighted images (long TE, 120ms) may beuseful for differentiating retinoblastoma from Coats’ dis-ease (retinal telangiectasis) or a persistent hyperplasticprimary vitreous, which are both hyperintense on thesescans (Figs. 1.3, 1.4).

Coats’ disease represents a congenital, non-hereditary, usu-ally unilateral vascular malformation of the retina, which mayeventually lead to retinal detachment. The pathophysiology isbreakdown of the blood–retina barrier resulting in a subretinallipoproteinaceous exudate, which typically does not containcalcifications and does not enhance on imaging studiesafter contrast media injection (Fig. 1.3). Peak prevalence islater than the typical retinoblastoma population, around six toeight years of age, although it can be seen as early as thefirst year of life. The typical clinical presentation is progressivevision loss. Local therapies include photocoagulation andcryogenic and laser ablation.

Persistent hyperplastic primary vitreous (PHPV): The pri-mary vitreous represents primitive mesenchymal tissue that

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occupies the posterior eye chamber during embryonic stagesof life. This tissue is gradually replaced by mature vitreous,persisting only at the small central canal between the retinaand the posterior aspect of the lens (Cloquet canal).A proliferation of this primary vitreous leads to hyperplasticfibrovascular tissue posterior to the lens and along the Cloquetcanal. PHPV is congenital and usually noted at birth or withina few weeks of life with leukocoria and microphthalmos. It isunilateral in 90–98% of cases. Untreated PHPV frequentlyprogresses to pthisis bulbi, due to recurrent intraocularhemorrhage.

Retinal astrocytic hamartomas represent masses in theglobe, which may have calcifications as well but are predomin-antly seen in patients with tuberous sclerosis. They are alsoseen rarely in patients with neurofibromatosis or in isolation.The majority of cases are asymptomatic and come to attentiondue to other clinical manifestations. In patients with tuberoussclerosis, the lesions are frequently congenital, usually mul-tiple, bilateral in 25% of cases, and may calcify. The majorityare non-progressive and do not require treatment. Imaging isprimarily performed to evaluate and follow other manifest-ations of tuberous sclerosis.

Teaching pointStaging and follow-up MR exams of patients with retino-blastoma requires imaging not only of the orbit, but also acontrast-enhanced MRI of the whole brain in order toevaluate for possible additional brain tumors. The risk of“trilateral” tumors is particularly high in patients with mul-tifocal and bilateral retinoblastomas.

references1. Blach LE, McCormick B, Abramson DH, Ellsworth RM. Trilateral

retinoblastoma – incidence and outcome: a decade of experience. Int

J Radiat Oncol Biol Phys 1994;29(4):729–33.

2. Dunkel IJ, Jubran RF, Gururangan S, et al. Trilateral retinoblastoma:

potentially curable with intensive chemotherapy. Pediatr Blood Cancer

2010;54(3):384–7.

3. Finger PT, Harbour JW, Karicioglu ZA. Risk factors for metastasis in

retinoblastoma. Surv Opthalmol 2002;47(1):1–16.

4. Kivelä T. Trilateral retinoblastoma: a meta-analysis of hereditary

retinoblastoma associated with primary ectopic intracranial

retinoblastoma. J Clin Oncol 1999;17(6):1829–37.


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Figure 1.2. Axial T1-weighted MR scan after injection of Gd-DTPAdemonstrates a large, inhomogeneously enhancing mass in thepineal gland in a different patient.

(a) (b)

Figure 1.1. (a) An axial CT scan through the orbits shows calcifications in both globes. (b) An axial T1-weighted MR scan after injection ofGd-DTPA demonstrates large, contrast-enhancing tumors in the globes bilaterally, with extraocular extension. The tumor in the right globeshows extrascleral extension and the tumor in the left globe shows extension into the optic nerve with associated contrast enhancement of theproximal optic nerve (arrow).

Trilateral retinoblastoma CASE 1

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(a) (b)

(c) (d)

Figure 1.3. Coats’ disease. Congenital, non-hereditary, vascular malformation of the retina, which produces a lipoproteinaceous exudate inthe subretinal space. Non-contrast and contrast-enhanced CT images of the right orbit (a, b) show an intraocular high-density lesion, whichrepresents the lipoproteinaceous exudate. No calcification and no enhancement after contrast media administration are noted. AxialT1-weighted non-contrast (c) and T1 postcontrast (d) fat-saturated images showing homogeneous intermediate signal of the intraocularlesion without contrast enhancement.


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(a) (b)

Figure 1.4. Persistent primary hypertrophied vitreous. Axial CT image through the right orbit (a) showing uniform high attenuation of thevitreous. T2-weighted image (b) shows the Cloquet canal (arrow), very characteristic of this condition.

Trilateral retinoblastoma CASE 1

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(c) Figure 1.4. (cont.) A postcontrast T1-weighted image (c) showsenhancement of the retrolental primary vitreous (arrow)


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CASE 2 Fibromatosis colli

Siobhan M. Flanagan, Kristen W. Yeom, Patrick D. Barnes, and Beverley Newman

Imaging descriptionA one-month-old male presented with a palpable right neckmass, which had been noticed 10 days previously. The masswas not perceived to be painful or bothersome to the patient.There was no reported fever or weight loss. He was feedingnormally and there was ipsilateral mild torticollis. He wasborn at 37 weeks by cesarean section due to cardiac deceler-ations during labor. Imaging evaluation with ultrasound (US)(Fig. 2.1a) demonstrated heterogeneous, mass-like enlarge-ment involving the right inferior sternocleidomastoid muscle(SCM). The mass tapered gently toward the SCM and wassurrounded by normal appearing SCM. The fascial planessurrounding the muscle were preserved. There were morpho-logically normal appearing prominent ipsilateral cervical chainlymph nodes. The lesion did demonstrate moderate internalvascularity on Doppler ultrasound (Fig. 2.1b).

An MRI was also performed in spite of the fact that the USappearance was strongly suggestive of fibromatosis colli. Thisdemonstrated enlargement of the inferior right SCM, withintact surrounding fascial planes. The process was confinedto the inferior SCM. There was increased T2 signal and het-erogeneous enhancement of the involved muscle (Fig. 2.1c,d, e). There were no calcifications present in the lesion. TheMRI findings also supported the diagnosis of fibromatosiscolli.

Clinically, the lesion decreased in size over time confirmedby follow-up ultrasound.

ImportanceFibromatosis colli is a form of infantile fibromatosis which israre and occurs solely in the SCM. Most cases present at two tofour weeks of age as a palpable neck mass. They typically occurin the inferior third of the SCM and can occur in either thesternal or clavicular head. Cases are usually unilateral, occurmore often on the right, and males are affected slightly moreoften than females. Torticollis toward the affected side is seenin about 20% of cases and is thought to be due to shortening orcontraction of the affected SCM. The precise mechanism isunclear. Suggested etiologies have included birth trauma or anin utero compartment syndrome related to fetal crowding andabnormal head position causing venous obstruction andmuscle injury followed by necrosis and fibrosis. Initially, themass may grow rapidly. Growth, however, slows and eventu-ally ceases. In two-thirds of cases, lesions completely regress bythe age of one year.

US is the preferred imaging modality for diagnosis since itis low cost, lacks ionizing radiation, and can well assesssuperficial lesions. The US appearance, although variable, is

usually diagnostic. US can demonstrate heterogeneousenlargement of the SCM, with at times the appearance of afocal mass with variable echogenicity. Extended field of viewimaging to show the entire length of the SCM can be useful.Color Doppler imaging may show hyperemia during theacute phase and decreased vascularity during the fibroticphase. Key findings include confinement within the SCMin the inferior one-third of the muscle and a characteristicspindle-shaped transition to normal muscle. It can beuseful to image the contralateral SCM for the purpose ofcomparison.

MR is not required to make the diagnosis of fibromatosiscolli, but is at times obtained during the initial workup of thecondition. MRI demonstrates fusiform enlargement of theaffected SCM, with variable T2 signal hyperintensity. Signalintensity decreases as the fibrotic stage ensues. There can behemorrhage in the affected muscle and the lesion can appearvery heterogeneous. However, it is not the appearance of theprimary lesion that should raise concern for an aggressiveneoplastic process such as neuroblastoma or rhabdomyosar-coma, but rather location or extension outside of the SCM andinfiltration into surrounding soft tissues. The presence ofcalcifications in fibromatosis colli is very rare, and should raiseconcern for neuroblastoma.

Radiographs may be requested by the clinician in cases oftorticollis, which will help exclude spinal fusion abnormalities.Rarely, there can be lytic change in the clavicle at the site ofattachment of the affected SCM in fibromatosis colli.

Typical clinical scenarioFibromatosis colli typically presents within the first 8 weeks oflife, most often in the first two to four weeks. The affectedSCM can continue to enlarge for two to three months. Even-tually, the fibrotic phase ensues, after which the size typicallydecreases over time.

Once confirmed by a combination of clinical assessmentand imaging, treatment of fibromatosis colli is conservative,and involves clinical observation and muscle stretchingexercises. Most cases resolve by the age of one year. Surgicalintervention is necessary in 10–15% of cases, where there issevere refractory disease after 1 year of age. The purpose ofsurgery is to prevent permanent contracture and plagioce-phaly. Surgical treatment consists of proximal or distalrelease of the SCM. Excision of the fibrous lesion is rarelyindicated. More recently, use of Botulinum toxin type A hasbeen used for treatment of refractory cases and may furtherprevent the need for surgical intervention.

Fibromatosis colli has been associated with hip dysplasia,perhaps also related to intrauterine crowding. More recent

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series have suggested that the association is less importantthan previously thought. US screening of the hips for disloca-tion or instability may be useful in the presence of fibroma-tosis colli and vice versa.

Differential diagnosisThe differential diagnosis for a neck mass in an infant ofthis age includes cervical lymphadenopathy, congenital neuro-blastoma (consider if calcifications are present andinvolves the paraspinal soft tissues medial to the SCM), andcervical extension of mediastinal thymus (common onthe left side, medial and posterior relative to the SCM).Rhabdomyosarcoma and cervical teratoma (consider if fatand calcifications are present) are very uncommon neoplasmsin this age group and location.

The presence of torticollis in an infant without a softtissue mass raises additional diagnostic possibilities. Spinalfusion anomalies are osseous causes that can usually beexcluded with cervical spine radiographs. Neurologic causesof torticollis include posterior fossa and cervical spinetumors as well as the Arnold Chiari malformation andsyringomyelia. Other miscellaneous causes include oculardeficiency, hearing deficits, and Grisel (C1/C2 subluxationassociated with inflammatory conditions such as retrophar-yngeal cellulitis) and Sandifer (torticollis or unusualneck movement associated with gastroesophageal reflux)syndromes.

Teaching pointFibromatosis colli is the most common cause of a cervical“mass” during infancy. It presents typically within the first 8weeks of life. The process is usually confined to the inferiorSCM and surrounding fascial planes should be intact. Thebest imaging modality for diagnosis is US, and that isusually all that is necessary. The appearance can be hetero-geneous and variable. If the mass is centered outside of theSCM or there is extension beyond the affected SCM or ifthere are internal calcifications, consider a neoplastic pro-cess such as neuroblastoma.

references1. Do TT. Congenital muscular torticollis: current concepts and review of

treatment. Curr Opin Pediatr 2006;18(1):26–9.

2. Lowry KC, Estroff JA, Rahbar R. The presentation and management of

fibromatosis colli. Ear Nose Throat J 2010;89(9):E4–8.

3. Meuwly JY, Lepori D, Theumann N, et al. Multimodality imaging of

the pediatric neck: techniques and spectrum of findings. Radiographics

2005;25(4):931–48.

4. Murphey MD, Ruble CM, Tyszko SM, et al. From the archives of

AFIP: musculoskeletal fibromatoses: radiologic-pathologic correlation.

Radiographics 2009;29(7):2143–73.

5. Robbin MR, Murphey MD, Temple HT, et. al. Imaging of

musculoskeletal fibromatosis. Radiographics 2001;21(3):585–600.

Figure 2.1. Fibromatosis colli, 1-month-old male. (a) Longitudinal gray-scale ultrasound image demonstrates a heterogeneous superficial lesionthat is contained in the sternocleidomastoid muscle (SCM), with smooth tapering to normal appearing SCM (arrows). Surrounding fascial planesare intact. (b) Sagittal color Doppler imaging demonstrates moderate internal vascularity to the lesion.

CASE 2 Fibromatosis colli

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Figure 2.1. (cont.) (c and d) Coronal T2-weighted imagesdemonstrate enlargement of the right SCM with heterogeneousincreased T2 signal. The process is confined to the inferior SCM.(e) Axial, fat-saturated, postcontrast T1-weighted image demonstratesheterogeneous enhancement of the involved SCM.

Fibromatosis colli CASE 2

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CASE 3 Craniopharyngioma

Camilla Mosci and Andrei Iagaru

Imaging descriptionA five-year-old girl presented to the emergency room withnew onset of nausea, vomiting, and headaches. MRIshowed a 36 × 26 × 30 mm multicystic suprasellar massextending superior to the third ventricle (Fig. 3.1a, b) withareas of calcification and ventriculomegaly. An Ommayadevice was placed in the right frontal lobe for cyst drain-age. Pathology was consistent with craniopharyngioma.She was followed with serial MRI and CT scans. Theimaging studies were stable for one and a half years whenan MRI scan demonstrated further increase in the cysticand solid components of the suprasellar mass withincreased ventriculomegaly. The patient underwent a rightfrontal endoscopic fenestration and partial resection of thesuprasellar mass, with removal of the blocked Ommayareservoir and placement of an external ventricular drainagesystem. Follow-up MRI showed increased size of the cysticmass and ventricles stable in size. However, there wasevidence of mass compression of the optic chiasm. Thepatient underwent MRI-guided placement of a new rightfrontal Ommaya reservoir into the cystic portion of hertumor. Therapy with 32P (β emitter) colloid chromic phos-phate was recommended by the treating physician.A diagnostic 99mTc sulphur colloid scan of the cystic tumorwas performed to evaluate the distribution of the injectedmaterial on the inner surface of the tumor and to excludethe presence of a leak from the craniopharyngioma to thecerebrospinal fluid (CSF) space. The 99mTc sulphur colloidscan showed radiotracer migration from the Ommaya res-ervoir and coating of the suprasellar mass. However,uptake was also seen into the ventricular system, due to aleak (Fig. 3.1c, d). Due to this leak to the CSF space, the32P chromic phosphate treatment was aborted in order toavoid excess radiation of normal central nervous system(CNS) structures.

ImportanceCraniopharyngioma is a benign tumor that arises alongthe path of the craniopharyngeal duct. It accounts for2–5% of all intracranial tumors and 5.6–13% of pediatricintracranial tumors and is classified into cystic, solid, andmixed. Despite its benign histologic appearance, prognosismay often be unfavorable due to mass effect on adjacentstructures and the optimal therapeutic approach remainscontroversial. Total resection is the treatment of choice,but when the tumor localization is unfavorable (proximity

and adherence to hypothalamus, pituitary stalk, visualapparatus, circle of Willis, floor of the third ventricle)limited resection followed by local irradiation is recom-mended. The rate of tumor recurrence is about 10–30%even after total resection. The utilization of radiotherapycan decrease the rate of tumor recurrence in patientswho undergo limited resection. However, it also maycause endocrine dysfunction, visual deterioration,radiation-related tumors, and cognitive impairment. Incystic tumors, radionuclide therapy with 32P chromicphosphate colloid is indicated. 32P is a β emitter thathas been shown to ablate the epithelial lining of the cyst,effectively reducing the rate of cystic fluid reaccumulationand reducing the cyst size. Compared to conventionalexternal beam radiotherapy, radionuclide therapy deliversa higher dose of radiation directly into the inner surfaceof the cyst, while reducing the radiation dose to tissuesadjacent to the tumor. It is important not only to obtainlong-term tumor control but also to preserve thepatient’s quality of life and stereotactic instillation of32P chromic phosphate colloid causes minimal risk andis effective as either primary or adjuvant treatment ofcraniopharyngiomas (Fig. 3.2).

Typical clinical scenarioClinical presentation is dependent on the size and site ofthe lesion and can vary from non-specific manifestationsof increased intracranial pressure to more specific symptomsas a result of pituitary hormone deficiencies or excess. Symp-toms include headache, nausea, vomiting, visual disturbance,seizures, and endocrine dysfunction (diabetes insipidus, amen-orrhea, sexual inadequacy, growth retardation).

Differential diagnosisCraniopharyngioma can be misdiagnosed as a pituitarytumor, metastasis, meningioma, epidermoid or dermoidtumors, hypothalamic-optic pathway glioma, hypothalamichamartoma, and teratoma. Other differential diagnosesthat should be considered include congenital anomalies(arachnoid cyst and Rathke’s cleft cyst), infectious/inflammatory processes (eosinophilic granuloma, lympho-cytic hypophysitis, sarcoidosis, syphilis, and tuberculosis),and vascular malformations (aneurysm of the internalcarotid or anterior communicating artery, arteriovenousmalformation).

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