CT and MR imaging of focal calvarial lesions

Orbital Intradiploic Epidermoid Cyst: A Case Report of a Rare Entity

Cranial epidermoid cysts are relatively rare. More frequently reported in middle-aged men with a wide variety of signs and symptoms such as headache, seizures, cerebellar and cranial nerve deficits/visual disturbance. The approach for surgical removal of the cyst depends on its size and location. In addition, a multidisciplinary team must be involved due to the common occurrence of misdiagnosis. We present the unusual age of presentation for intradiploic epidermoid cysts. A 14-year-old boy is complaining of a 2-month history of painless progressive swelling of the right eyebrow. Magnetic resonance imaging revealed an intradiploic cystic mass within the right frontal bone. The cystic mass was removed, and histological examination confirmed the diagnosis of an epidermoid cyst. This case illustrated the potential of developing intradiploic epidermoid cysts in pediatrics.

A Report of Two Simultaneous Different Skull Vault Boney Pathologies: An Extremely Rare Clinical Scenario

Primary calvarial boney tumors are generally rare in clinical practice. Multiple primary skull neoplasms are less frequent, typically associated with genetic disorders or familial syndromes. Sporadic cases of multiple skull tumors are exceptionally rare. We present a unique scenario of a 32-year-old female patient who had two right-sided skull vault lesions, one located over the right parietal area and the other in the right retro-auricular region. The lesions exhibited different behaviors over several years. The workup revealed that the two skull lesions were of two pathologies. The standard academic approach for clinical analysis attributes the symptoms often to one pathological process until proven otherwise. This case highlights the significance of expanding the differential diagnoses and incites clinicians to consider multiple pathologies in specific clinical settings.

Comparison of computed tomography and magnetic resonance imaging in evaluation of skull lesions

Background

Computed tomography (CT) and magnetic resonance imaging (MRI) have been incorporated into the basic imaging tools for evaluation of skull lesions. Despite the known advantages and disadvantages of CT and MRI in various aspects of evaluating skull lesions, it is not always feasible to perform both CT and MRI in evaluation of the same patient. The purpose of this study is to compare CT and MRI in evaluation of various skull lesions and to determine which imaging modality out of the two is more appropriate in evaluation of skull lesions and their characterization.

Results

There was no statistically significant difference between CT and MRI for detection of number of lesions, distribution of lesions, margins of the lesions, nature of the lesions, zone of transition, cortical breach, intralesional calcification, intralesional hemorrhage, associated soft tissue, and invasion into brain parenchyma (p value > 0.05 in all these parameters). Dural involvement was picked up better on MRI as compared to CT (p value 0.031). Another advantage of MRI over CT was better characterization of lesions by diffusion weighted imaging.

Conclusion

CT and MRI are equally efficient in providing adequate diagnostic information in various skull lesions and each of them can be used independent of the other to characterize and diagnose the lesions of skull. The slight advantage of MRI over CT is detection of dural involvement.

Headache Attributed to Disorder of the Cranium and Base of the Skull

The article describes the approach to imaging that clinicians should adopt in cases of headaches suspected to be secondary to cranial vault or skull-base disorder. As a rule, computed tomography (CT) is superior to MRI for most of the osseous lesions, and lesions of the middle and external ear. MRI provides a complimentary role to CT and is the modality of choice in a few conditions such as extraosseous neoplasms of the skull base.

Giant Intradiploic Epidermoid Cyst in the Occipital Bone: A Case Report

Epidermoid cysts are uncommon intracranial tumors. As one of the extradural types of epidermoid cysts, intradiploic epidermoid cysts are even rarer tumors and occur in any part of the skull. We herein report a rare case of a giant intradiploic epidermoid cyst of the occipital bone. A 57-year-old woman presented with a 1-year history of localized headache in the occipital area. CT and MRI showed an extradural mass measuring 50×70 mm in the occipital bone with bony destruction. The patient underwent surgical resection. The tumor was completely removed with its capsule. There was no extension to the intradural space. The pathological report confirmed that the tumor was an epidermoid cyst. Follow-up MRI 24 months after the operation showed no recurrence. The headache was well controlled without any medications. We report a rare case of intradiploic epidermoid cyst with clinical and radiologic features and surgical treatment. It is important to consider this diagnosis for a patient with persistent regional headache with or without a growing scalp mass.

The lucent (CT) and enhancing (MR) rim, a sign of Paget's disease of the skull: case report

Osteoporosis circumscripta is sometimes observed at the skull vault and corresponds to the initial stage of Paget's disease of the bone. Differentiating osteoporosis circumscripta from other reasons for osteolytic images of the vault may be difficult. We report a case of osteoporosis circumscripta of the frontal bone. A lucent rim seen on CT scan, which was enhanced on gadolinium-enhanced MRI, delineated the abnormal bone. The patient was a 50-year-old woman who had CT scans of the skull for chronic sinusitis. Pathology examination showed typical bone changes of Paget's disease. The lucent and enhancing rim sign may help in differentiating Paget's disease from other conditions.

Radiological review of skull lesions

Abstract

Calvarial lesions are often asymptomatic and are usually discovered incidentally during computed tomography or magnetic resonance imaging of the brain. Calvarial lesions can be benign or malignant. Although the majority of skull lesions are benign, it is important to be familiar with their imaging characteristics and to recognise those with malignant features where more aggressive management is needed. Clinical information such as the age of the patient, as well as the patient’s history is fundamental in making the correct diagnosis. In this article, we will review the imaging features of both common and uncommon calvarial lesions, as well as mimics of these lesions found in clinical practice.

Teaching Points

• Skull lesions are usually discovered incidentally; they can be benign or malignant.

• Metastases are the most frequent cause of skull lesions.

• Metastatic lesions are most commonly due to breast cancer in adults and neuroblastoma in children.

• Multiple myeloma presents as the classic “punched out” lytic lesions on radiographs.

• Eosinophilic granuloma is an osteolytic lesion with bevelled edges.

Spectrum of lytic lesions of the skull: a pictorial essay

Abstract

Lytic lesions of the skull include a wide range of diseases, ranging from benign conditions such as arachnoid granulations or vascular lacunae, to aggressive malignant lesions such as lymphomas or metastases. An early and correct characterisation of the nature of the lesion is, therefore, crucial, in order to achieve a fast and appropriate treatment option. In this review, we present the radiological appearance of the most frequent lytic lesions of the skull, describing findings from different imaging modalities (plain X-rays, CT and MRI), with particular attention to diagnostic clues and differential diagnoses.

Teaching Points

• Osteolytic skull lesions may be challenging to diagnose.

• Association of different imaging techniques may aid image interpretation.

• Clinical information and extensive knowledge of possible differential diagnoses is essential.

• Some osteolytic tumours, although benign, may present as locally aggressive lesions.

• Malignant lesions require accurate staging, followed by variable treatment approaches.

Cranial Focal Nodular Haematopoietic Hyperplasia: A case report and literature review

Focal Nodular Haematopoietic Hyperplasia (FNHH) is an uncommon, benign, osteolytic lesion and so far, has not been reported cranially. Here, we report the first cranial case of a patient with right frontal bone FNHH and describe the clinical history, management and follow up with review of the literature of this rare pathology.

Intradiploic Pterional Epidermoid Tumor: A Case Report and Review of literature

Intradiploic epidermoid cyst is an uncommonly occurring neoplasm, and only about 200 cases are reported in the form of isolated case report. It is presumed to occur due to ectodermal cells in inclusion in the bone tissue during embryonic life neural tube closure. It commonly remains asymptomatic or rarely presents as a bony lump in the skull bone. Authors report present an interesting case, which presented with swelling, and underwent successful surgical resection. Pertinent literature along with diagnosis and management is briefly reviewed. These lesions can erode the bone and involve the brain parenchyma due to their proximity to the brain. Radiological imaging is very helpful in accurate diagnosis of these lesions and in differentiating intradural from intradiploic varieties of epidermoid. We present an unusual case of this pathology.

Imaging of focal calvarial lesions

Focal calvarial lesions may present as a visible, palpable, or symptomatic lump; however, with increasing use of cross-sectional imaging they are often encountered as an incidental finding. Knowledge of the possible disease entities along with a structured approach to imaging is required to suggest an appropriate diagnosis and assist in management planning. Abnormalities range from common neoplastic lesions to rarer congenital conditions, benign pathologies, and calvarial defects that can mimic lesions. The aim of this article is to demonstrate the salient imaging features that may help to limit the differential diagnosis of a focal calvarial lesion.

Multiple occipital, parietal, temporal, and frontal foramina: a variant of enlarged parietal foramina in an infant

BACKGROUND

Calvarial lesions are often detected incidentally in routine radiology. Most lytic lesions of the skull are benign. Enlarged parietal foramina are benign lesions caused by deficient intramembranous ossification.

CASE REPORT

An 11 month-old female patient was admitted with a mass on the right of the back of the head. Physical examination showed a soft 5 cm mass area with no palpable bone in the right occipital. The family history revealed a similar mass in a maternal cousin that resolved over time. Craniography showed lytic lesions, and there were no other pathologies on a complete skeletal X-ray. Computed tomography (CT) showed regular-shaped defects in the bilateral temporal bones, right parietal bone, bilateral frontal bones in the upper-medial orbital wall, and particularly in the occipital bone. The well-defined contours, absence of a soft tissue component, and normal structure and density of the adjacent calvarial bones all pointed to a congenital defect. No change in the lesions was observed during a three-year ultrasound follow-up period.

CONCLUSION

To the best of our knowledge, this is the first described case of multiple occipital, parietal, temporal, and frontal foramina in the cranium. A diagnosis of enlarged parietal foramina variant should be considered after ruling out the differential diagnosis in patients with multiple calvarial lesions. CT may provide valuable findings for the differential diagnosis, and sonography may be used for follow-up.

Diabetes insipidus associated with a thickened pituitary stalk in a case of Langerhans Cell Histiocytosis

Diabetes insipidus (DI) associated with a thickened pituitary stalk is a diagnostic challenge in the pediatric population. Langerhans Cell Histiocytosis (LCH) is a rare cause of this entity. A 4-year-old male child presented with central DI of 1-year duration, associated with a thickened pituitary stalk. The etiology for the same remained elusive as the patient had no other manifestation to suggest LCH. A year later, the patient developed a left frontal scalp swelling. Neuroradiology demonstrated multiple punched out osteolytic lesions in both the frontal bones. The infundibulum was thickened and showed post-contrast enhancement. Histology and immunohistochemistry (IHC) of the biopsy specimen confirmed LCH. The child was administered chemotherapy according to LCH protocol, which resulted in 33% reduction in the size of the skull lesions. The DI was controlled with medical management. The present case highlights the need for serial follow-up and magnetic resonance (MR) imaging that led to a diagnosis of LCH. The clinical presentation and management of central DI and a thickened pituitary stalk is presented and the relevant literature is discussed.

Imaging pattern of calvarial lesions in adults

Calvarial lesions often present themselves as clinically silent findings on skull radiographs or as palpable masses that may cause localized pain or soreness. This review aims to explore the radiographic, computed tomography (CT), and magnetic resonance imaging (MRI) characteristics of calvarial neoplastic, inflammatory, and congenital lesions that are common in adults in order to facilitate a structured approach to their diagnosis and limit the differential diagnosis. In addition to reviewing the literature, we reviewed the records of 141 patients of the Montreal Neurological Institute and Hospital with radiologically documented calvarial lesions between 2001 and June 2009. CT is ideal for detecting bony lesions and is helpful in precisely localizing a lesion pre-surgically. MRI is best at identifying intradiploic lesions before they affect the cortical tables and is able to establish extraosseous involvement, especially when paramagnetic contrast is employed.

Surgical resection of osteolytic calvarial lesions: clinicopathological features

OBJECTIVE

Osteolytic calvarial lesions are infrequent findings. Some cases are found incidentally during cancer staging or subsequent to unspecific symptoms. There are no standardized algorithms for the treatment of such lesions. Thus, the aim of this study was to describe the clinicopathological features and surgical outcome in various osteolytic calvarial lesions.

MATERIAL AND METHODS

The clinical presentation, radiological imaging findings, surgical treatment and histopathological findings of 36 patients who underwent surgery for an osteolytic calvarial lesion at our institution between 1998 and 2008 were reviewed.

RESULTS

Thirty-six osteolytic calvarial lesions were identified in 20 men and 16 women. Mean age at diagnosis was 37 years. Ten patients were children younger than 15 years. Five lesions were detected during cancer staging. Complete removal of the calvarial lesions was achieved in all patients without complications. The most common histopathological diagnosis was metastasis (n=9), Langerhans-cell histiocytosis (n=9), and intraosseous hemangioma (n=5). In two asymptomatic patients, histopathological findings revealed metastases of a previously unknown tumor. In two other patients known to suffer from cancer, histopathological findings indicated intraosseous hemangioma and intraosseous meningioma, respectively. Reconstruction of the calvarial defect was performed in 24 cases with poly-methyl-methacrylate and with titanium mesh in 1 case.

CONCLUSIONS

Osteolytic calvarial lesions can be found in any age group. The histopathological examination reveals various entities, and in some instances it was not concurrent with a primary malignancy. Because surgical morbidity is low, we recommend complete resection of osteolytic calvarial lesions with reconstruction when feasible.

The lucent rim: a radiographic and computed tomography sign of Paget's disease of the skull

In seven of eight patients with osteoporosis circumscripta of the cranial vault, the pagetic bone lacunae were separated from the normal bone by a lucent rim visible on conventional radiographs and computed tomography scans. The contour of the rim was sharp on the side of the healthy surrounding bone and hazy on the side of the defect. To our knowledge, this sign has been reported in one single previous article dealing with two pagetic patients with the bisphosphonate escape phenomenon.

[Solitary hypermetabolic bone focus in the initial extension study of a prostate carcinoma]

56 year old male who was diagnosed of Prostatic Neoplasm by transrectal biopsy after elevated PSA level was found by chance in a routine control. The initial extension study with abdominal and pelvic CT did not show significant radiological abnormalities. This was followed by a whole body bone scintigraphy with 99mTc-MDP that showed a solitary hypermetabolic lesion within skull. A SPECT study placed this lesion at the left occipital region. An MRI and a CT head scan were carried out to characterize the isotopic lesion, finding no bone abnormalities to justify the mentioned uptake. Given the absence of a radiological benign diagnosis, a further FDG-PET scan was carried out which did not show either increased glycolytic activity at the left occipital region, or in the prostatic gland. In order to guide the biopsy, a CT head scan was repeated which showed what appeared to be an incipient blastic lesion in the scale of the left occipital bone, establishing the differential diagnosis between a metastasis and a benign process. The anatomopathologic analysis of the bone tissue describes a necrotic process without inflammatory reaction (osteonecrosis).

Méningiome intra-osseux de la voûte du crâne : confrontation anatomo-radiologique

Intraosseous meningiomas are rare ectopic meningiomas. The authors report the case of a hyperostotic intraosseous meningioma of the parietal bone without dural extension. The preoperative imaging findings, as well as imaging features of the surgical specimen and pathologic findings are discussed.

Dural enhancement with primary calvarial lesions

The purpose of this study was to relate the pathological and imaging features of dural enhancement and meningeal sign ("dural tail") on contrast-enhanced T1-weighted magnetic resonance (MR) images from patients with primary calvarial lesions as well to assess the accuracy of MR imaging in predicting dural invasion. Thirty-two calvarial tumors studied with contrast-enhanced MR imaging and histopathological examination of the dural specimens were reviewed. Sixteen patients presented dural enhancement, eight with tumor invasion. Tumoral invasion of the dura was observed in one case without enhancement. Malignant lesions showed enhanced dura more commonly than benign lesions (P=0.02). Nodular and discontinuous dural enhancement was statistically associated with dural invasion (P=0.05). Dural tail did not show a specific pathological association. Meningeal enhancement is a nonspecific reaction to calvarial lesions unless nodular and discontinuous. False-negative and -positive cases of dural invasion imply some limitation of contrast-enhanced MR imaging in predicting dural invasion by calvarial neoplasms.

Calvarial masses of infants and children. A radiological approach

Children frequently present with asymptomatic head lumps that have been discovered by their parents or by their hairdressers. Other children present with painful lumps or symptoms of intra-cranial masses with calvarial involvement. Imaging plays an important role in the diagnosis of such masses and in subsequent surgical planning. We present a review of the types of lesion that may present in these ways.

Diagnóstico de las lesiones de la calota. Selección de variables por redes neuronales y regresión logística

OBJECTIVES

To establish the minimun set of features needed in the diagnosis of calvarial lesions using computed tomography (CT) and to assess the accuracy of logistic regression (LR) and artificial neural networks (NN) for their diagnosis.

MATERIAL AND METHODS

167 patients with calvarial lesions as the only known disease were enrolled. The clinical and CT data were used for LR and NN models. Both models were tested with the jacknife method. The final results of each model were compared using the area under ROC curves (A 2 ).

RESULTS

The lesions were 73.1 % benign and 26.9% malignant. There was no statistically significant difference between LR and NN in differentiating malignancy. In characterizing the histologic diagnoses, NN was statistically superior to LR. Important NN features needed for malignancy classification were age and edge definition, and for the histologic diagnoses matrix, marginal sclerosis and age.

CONCLUSIONS

A minimum four features is needed to diagnose these lesions, not being important patients' symptoms. NNs offer wide possibilities over statistics for the calvarial lesions study besides a superior diagnostic performance.