Female: 9 years and 4 months.
Right parietal tumefaction,
for about 15 days.
No trauma in anamnesis.
MRI without contrast already performed MR in another hospital.
Neoplasm with an inhomogeneously high signal in all sequences (FLAIR axial images,
coronal image T2w,
prominent in the inracranial soft tissues and in the intracranial side.
There is no signal alterations in the adjacent nervous tissue,
nor perilesional edema.
Imaging recommendation: CT to evaluate bone involvement.
Osteolytic lesion often characterized by internal and external cortical involvement (biconvex aspect). Soft tissue in the center of the osteolytic lesion
CT feature: osteolytic lesion associated with the presence of pathological tissue with soft tissue density.
Histological examination: Langherans Cell Histiocytosis (LCH).
Imaging recommendation: Stadiation includes the study of the hypophysis to exclude multiple localization.
LCH can be single or multiple and this information is relevant for the subsequent clinical management.
Fig. 3: MR study of the sellar region. T1-w images before (a) and after contrast administration (b) exclude localization of pathology in this patient.
T1-w images before (c) and after contrast administration show pathologic localization in the hupophysary peduncle, which appears pathologically enlarged (arrows).
Patient with Langherans Cell Histiocytosis: unifocal form.
Another patient with multiple Langherans Cell Histiocytosis localizations. MR study (a-f),
and scintigraphy (i).
There is an osteodural lesion localized in the left fronto-orbitary region,
characterised by “geographic” osteolysis with extensive involvement of the skull.
There is no associated periostal reaction.
The lesion presents dishomogeneous signal before and after contrast material administration and is associated to thickening of the adjacent dura.
The periphery of the lesion shows increased uptake at scintigraphy.
Patient with Langherans Cell Histiocytosis: multiple lesions.
Fig. 6: Axial CT: well defined osteolytic lesion (right orbit) with soft tissue.
Multiple well defined osteolytic lesions.
A 12-year-old boy arrives in our Emergency Department with stiff neck unresponsive to therapy.
CT and MR examination shows osseous rarefaction associated with soft tissue bone expansion. Fig. 8
Fig. 8: MR and CT study of another patient with histiocytosis. Axial T2-w images (a) and T1-w images before (b) and after contrast administration show an extensive signal alteration of the bones of the cranial base (occipital bones and atlas) associated with dishomogeneous contrast enhancement.Te signal alteration shows extraosseous extension to the soft tissues of the rinopharynx. CT scan shows rarefaction of the involved bones. A diagnosis of histiocytosis was made.
Imaging recommendation: MR and CT features showed no univocal diagnosis
Histological examination needed: Langherans Cell Histiocytosis
In this location MRI in helpfull also to evaluate paraspinal and epidural space extention.
In the atlantoaxial LCH is necessary to be aware for dislocation and spine cord suppression.
an early and accurate diagnosis of atlantoaxial LCH is of important clinical significance.
- to evaluate location,
and pathological bone fracture.
- to define the features of lytic lesion: osteolytic destruction is the main radiographic manifestation.
MRI: to characterize soft tissue in case of LCH.
Differential Diagnosis at this location:
- Ewing's sarcoma
All of them are characterize with infiltrative and penetrating bone destruction accompanied by periosteum reaction.
To achieve a usefull diagnostic hypothesis is necessary to consider radiological findings,
epidemiology and remember "rare" locations!
Patient with Atlantoaxial Langherans Cell Histiocytosis: unifocal form.
Male 1 years and 6 months old: at Emergency Room for squint convergent to the left eye,
during last week.
Performs CT without contrast medium.
Fig. 9: Lytic lesion of the temporal bone petrous apex. CT scan. Axial image (a, bone reconstruction algorithm) shows an osteolytic lesion at the temporal bone petrous apex (arrow), with associated pathological tissue (b, axial - c, coronal, arrows).
Well defined osteolytic lesion at the temporal bone petrous apex associated with the presence of pathological tissue with soft tissue density.
CT features: osteolysis with "geographic map" characteristics,
in the absence of sclerosis or periosteal reaction.
Evaluate the extension to the surrounding bone structures (eg.
internal auditory canal,
ossicular chain). Needed a MRI study.
Age-related differential diagnoses (benign and malignant):
- Langherans Cell Histiocytosis (LCH)
- Apical Petrositis
- Rabdomioarcoma (RMS)
Imaging recommendation: contrast-enhanced MRI
Fig. 10: MRI. The lytic area corresponding to an inhomogeneously hyperintense tissue on T2w images (a, axial T2w) and with inhomogeneous strong contrast enhancement (c, axial GdT1w) with a necrosis/central colliquation area. The values of ADC (d, ADC map) are inhomogeneous, elevated in the central portions of the lesion. No intracranial extension is showed. Ipsilateral mastoiditis.
MRI has its role in the characterization of the pathological tissue associated with lytic lesion and in the evaluation of a possible brain parenchymal involvement.
These information address the type of clinical treatment.
- Skeletal survey to exclude the presence of further skeletal localizations.
- The role of scintigraphy is important because in some cases the radiographic evaluation can be negative.
The skeletal survey can provide information for further skeletal localizations,
located where it is necessary an immediate surgery to avoid complications.
RMS and LCH are both rare but potentially fatal neoplasms in children.
The temporal bone is a less common location with only 8%–10% of cases of RMS of the head and neck3 and 19%–25% of LCH cases.
Langherans Cell Histiocytosis (LCH)
- LCH is a heterogeneous illness characterized by the proliferation of monoclonal Langherans cell histiocytes that form granulomas within any organ system.
- The new trend is divided into three groups on the basis of the number of LCH lesions and systems involved and include unifocal form,
and multifocal multisystem [Zaveri J et al.].
- Presentation (location-related):
- Calvarial: pain,
- Mastoid: pain,
chronic otitis externa,
retroauricular subscalp mass
- Retroorbital: exophtalmos,
- Hypophysis/pituitary infundibulum: central DI,
- Natural history is variable depending on age of onset and extent of involvement.
In multifocal/systemic LCH mortality may approach 18%. The main manifestation of LCH in the atlas and axis is the neck pain.
- LCH may appear at any age. The peak age are from 1 to 3 years or 5–10 years; mean age is 12.9-year-old,
the median age was 8-year-old and patients under 15 years accounting for 75.6%.
- In 75%–80% case of LCH manifested as bone destruction, especially in flat bone and spine.
TAKE HOME MESSAGE:
Lesions may be single or multiple: an investigation extension is required to exclude other extracranial bone locations (example: hepatosplenomegaly,
because this is a necessary information to plan tratments.
A pituitary-peduncle evaluation is always required. The involvement of the dural breasts makes the type of treatment change.
In this scenario,
imaging play an important role in clinical decision-making: an early and accurate diagnosis of atlantoaxial LCH is of important clinical significance to avoid sequele.
Lytic lesions at the temporal bone could be aware for different diagnosis.
16-year-old male with recurrent headaches and progressive bilateral loss of visual acuity.
History: progressive monolateral neurosensorial hearing loss diagnosed when he was 5-years old. Ophthalmologic evaluation: retinic hemangioblastomas.
Fig. 13: MR study. Axial T2-w (a) axial T1-w (b) post-contrast T1-w axial and sagittal images (c,d) show two separate tumors one localized in left the cerebello-pontine angle (cause of the hearing loss) and one localized in the left cerebellar hemisphere, characterized by an ample cystic component and by a parietal nodule which shows CE.
The left cerebellar lesion is consistent with an hemangioblastoma.
Localization and signal characteristics of theleft cerebello-pontine lesion are consistent with an endolymphatic sac tumour.
These findings were suspect for Von-Hippel Lindau (VHL) syndrome,
which was genetically confirmed.
Imaging has an important role at diagnosis and follow-up of patients with VHL syndrome,
also to exclude body localizations (such as the pancreas) and malignant transformation in such sites.
9-year-old female referred to Pediatrician for rhinolalia and snoring.
Fig. 15: Heterogeneous lesion with strong contrast-enancement within the clival region.
Girl 9-year-old and 4-month-old girl: at Emergency Room for maxillary sinusitis for about 1 month (antibiotics with improvement),
headache treated without benefit for about 15 days.
CT examination performed.
Fig. 16: Spheno-ethmoid neopalsm with osteolysis, also extended to the ethmoidal planum.
Imaging recommendation: Needed MRI examination to better evalutate CNS.
Total body CT revealed no other localizations.
Histological diagnosis of Ewing's Sarcoma.
•Round cell bone sarcoma presenting in vertebral body/sacrum of adolescent/young adult
•Pathology: Grayish white tumour with poorly demarcated margins.
Mesenchymal cells with slight differentiation toward neuroectodermal cells.
Small round cells with round nuclei and high mitotic rate.
•Presentation: localized pain; fever,
associated neurological symptoms.
Distant metastases are frequent
•Treatment: neoadjuvant chemotherapy given prior to surgery or radiotherapy
•Surgery: wide margins if possible
•Radiotherapy:surgically inaccessible lesions,
stage 3 disease,
poor response to chemotherapy
TAKE HOME MESSAGE:
Imaging goal: to define the extent of the lesion and the relationships with the adjacent structures (CNS structures) for biopsy and for management.
CT and MRI has a complementary role.
Male 14 yo referred to Emergency Department for left exotropia.
Fig. 18: Non-contrast-enhanced computerized tomography (CT), axial: Expansile boney lesion located in the left sphenoid. Irregular sclerotic bone edges.
Fig. 19: MRI in the axial plane. Heterogeneous hyperintense in T2- weighted image (left) with strong post-contrast enhancement in T1- weighted image (right).
Imaging features: CT MRI findings were suggestive of a highly vascular lesion.
Strongly suggested to perform angiography.
Histological examination: aggressive giant cell granuloma.
The giant cell reparative granuloma (GCRG) is a rare non- neoplastic lesion most commonly associated with mandibular and maxillary regions.
Few cases of giant cell reparative granulomas have been reported in the cranial vault.
- Osteoblastoma: sclerotic components.