Pictorial essay

Skull radiographs as a guide for diagnosing systemic disorders (Pictorial Atlas) Subbarao Kakarla1,*

1

KIMS Foundation and Research Centre, Minister Road, Secunderabad - 500003, Telangana, India

*Corresponding author: Prof. Kakarla Subbarao, MS, D.Sc. (HON), is to deal with osseous portions of the calvarium and FRCR, FACR, FICP, FSASMA, FCCP, FICR, FCGP, Chairman, KIMS to study the abnormalities which may contribute to

[email protected] Foundation and Research Centre, Minister Road, Secunderabad - developmental abnormalities are included in the Received500003, Telangana,16 September India. Email: 2015; Revised 20 November 2015; Tablethe final 1 and diagnosis. 2. Systemic disorders, congenital/ Accepted 1 December 2015; Published 11 December 2015 Table 1: Systemic disorders. Citation: Kakarla S. Skull radiographs as a guide for diagnosing

l Congenital/ Developmental 50. 012 systemic disorders (Pictorial Atlas). J Med Sci Res. 2016; 4(1):41- l Copyright:DOI: http://dx.doi.org/10.17727/JMSR.2016/4- © 2016 Kakarla S. Published by KIMS Foundation and l InflammatoryInfections/ Infestations the terms of the Creative Commons Attribution License, which l Hemopoietic permitsResearch unrestricted Center. This use,is an distribution,open-access andarticle reproduction distributed inunder any medium, provided the original author and source are credited. l Metabolic and endocrinal

l

Introduction l NeoplasticToxic – Metastasis and myeloma As compared with the past, the current medical l Miscellaneous practice ignores the usefulness of taking skull radiographs. Radiographs of the skull may not Table 2: Congenital/ Developmental abnormalities. contribute to the diagnosis of brain injury, bleeding l or other space occupying lesions in the brain. l Pycnodysostosis disorders, but this paper does not include all brain l Camurati engelmann dysplasia lesions.Intracranial Conventional calcifications radiographs may give of athe clue skull to play brain a l

l Craniocleidodysostosis systemic disorders. Antero posterior and lateral Craniometaphyseal dysplasia – Pyle’s l viewsmajor role are in taken arriving routinely. at the Advancedfinal diagnosis imaging of many like Fibrous dysplasia computed tomography (CT) and magnetic resonance l Osteogensis imperfecta imaging (MRI) may not be always necessary. l Phacomatosis However, clinical history and radiographs of the l Mucopolysaccharidosis other skeletal areas are very important in arriving l Craniostenosis at a final diagnosis. The main objective of this paper Vol. 4 | Issue 1 | January - March 2016 41 Osteopetrosis (Marble ) is also called Common radiological findings The calvarium is dense and thick (more at the base) defective . Radiologically, bones are with narrowing of neural foramina. The paranasal Albers-schonberg disease which results from sclerotic and thick, but weak and brittle. Two sinuses are under developed (Figure 1a,b,c). separate sub types exists. One, infantile autosomal recessive osteopetrosis and two, benign adult autosomal dominant osteopetrosis.

(a) (b) (c)

Figure 1: a, b.

Osteopetrosis – AP and lateral views of pediatric skull, c. Adult skull. Pycnodysostosis are also sclerotic (Figure 3a). However, from the It is a rare autosomal recessive bone dysplasia radiographs of the skull one cannot diagnose this characterized by and short stature entity and radiographs of long bones are necessary (Figure 3b). essentialand is also for known normal as Toulouse-Lautrec function. syndrome. It is due to genetic deficiency in , which is Common radiological findings The features include frontal bossing, Wormian bones, mid line defects and obtuse angle of the mandible (Figure 2a,b).

(a) (b)

Figure 3: bones, a. Lateral skull, b. Long bones. Camurati engelmann dysplasia – Dense sclerotic

sclerosis of calvarial bones (Table 3) may be of help. At this juncture, a differential diagnosis of diffuse Figure 2a: Figure 2b: Craniometaphyseal dysplasia Open fontanelle, mandible with obtuse WormianPycnodysostosis bones. – angle.Pycnodysostosis – Dense long bones (Figure 4a,b). Basic cranium with flaring of metaphyseal ends of Camurati engelmann dysplasia Craniocleidodysostosis (CCD) It is a progressive diaphyseal dysplasia with sclerotic It is a developmental dysplasia. The radiological dense diaphyses of long bones. The skull bones characteristics of the skull include open fontanel,

42 Journal of Medical and Scientific Research Table 3: bones. Differential diagnosis of diffuse sclerosis of calvarial Developmental

l Osteopetrosis

l Pycnodystosis

l dysplasia Camurati engelmann – Progressive diaphyseal (a) (b) l Figure 5a,b: l Pyle’sVan buchem’s disease disease- Craniometaphyseal dysplasia Wormian bones. CCD – Brachicephaly, midline defects and l Idiopathic hypercalcemia

l Fibrous dysplasia

l Hyperphosphatemia

l Cyanotic heart disease

l Hemopoietic Other causes

l Hemolytic anaemia

l Mastocytosis Figure 5c:

l CCD - Note the dysplastic clavicles. monostotic, polyostotic or a part of Albright l MyelofibrosisHyper/ Hypoparathyroidism with secondary l syndrome. Radiological findings of craniofacial hyperparathyroidism appearancesfibrous dysplasia have include been expanded described. outer One table is purely with l Dilantin therapy lytic,little effect the second on inner purely table. scleroticThree types and of the radiological third is l Fluorosis mixed sclerotic and lytic changes. Sclerotic changes are mainly in the basicranium and face. A lytic area l Paget’s disease surrounded by dense sclerosis is the skull bones, is

Intypical the valut, of a “blister” the outer appearance. table is expanded with a lytic

(Figure 6a,b,c,d). When the skull and facial bones are extensivelylesion in the involved centre. with This sclerosis, is called it a is “bone described blister” as Leontiasis ossea (Figure 6e). (a) (b)

Figure 4: Craniometaphyseal dysplasia, a. skull, b. Metaphyseal

flaring of femora (Erlenmeyer flask appearance). midline defects and Wormian bones. Radiological as there is dysplasia of calvicles (Figure 5a,b,c). examination of the clavicles confirms the diagnosis Fibrous dysplasia (FD) replacement of the normal bone. It may be Figure 6a: It is developmental aberration with fibrous FD frontal bone – Sclerotic. Vol. 4 | Issue 1 | January - March 2016 43 Figure 7:

OI - Wormian bones. Figure 6b: FD involving basicranium. Table 4:

l OsteogenesisDifferential imperfectadiagnosis of Wormian bones.

l

l Pycnodysostosis

l Cretinism

l Rickets

l

Hajdu–Cheney syndrome (Figure 8) (c) (d)

Figure 6c,d: FD of skull, lytic area with dense sclerotic border (Bone blister).

Figure 8: Wormian bones and wide sutures. Hajdu-Cheney syndrome with scaphocephaly – Phacomatoses

neurocutaneous disorders. These are multisystem Figure 6e: Leontiasis ossea. disordersThese are that neuro-oculo-cutaneous have characteristic centralsyndromes nervous and system, ocular and cutaneous lesions of variable Osteogenesis imperfecta (OI) congenita & severity. The osseous system may also be involved in tarda (eight types of congenital forms) some of these (Table 5).

Table 5: Some of the disorders.

There are four major types, which are I - Mild, Blue l Tuberous sclerosis sclera; II - Perinatal, Lethal; III – Uncommon, Severe; l RadiologicalIV – Uncommon, features Resembles include 1. a variable spectrum. l NeurofibromatosisCystic angiomatosis Intrauterine recognition by ultrasound is known. l Sturgeweber syndrome Radiological features include fractures, lucent bones, l Turcot syndrome

4 (Figure 7). Basilar impression is often noted. l Gardener syndrome unossified skull bones with Wormian bones in Table 44 Journal of Medical and Scientific Research Tuberous sclerosis (Epiloia) The clinical triad includes sebaceous cysts over the Neurofibromatosis: Comparison between NF-1 and TableNF-2 (Table6: 6). Skull radiographs often overlap the intracranial face, seizures and mental deficiency of the brain. NF - 1 Comparison between NF-1NF – and2 NF-2. 1. Von Recklinghausen’s 1. Bilateral acoustic calcifications due to gliosis (Figure 9). disease schwannomas 2. 1/4000 (represents 90% 2. 1/150,000 (<10% of NF Figure 9: of NF cases) cases) Tuberous sclerosis 3. Chromosome 17 3. Chromosome 22

in bone resemble 4. Prominent skin 4. Minimal skin changes – Sclerotic islands manifestations

- Periventricular calcifications. In NF2, bilateral acoustic schwannomas are common (Figure 11).

Neurofibromatosis (NF) This is one of the neurocutaneous syndromes and these, NF1 and NF2 are important. Figure 11: eight different types have been described. Out of acoustic schwannomas.NF2- Bilateral macrocranium, asymmetrical skull, empty orbit Radiological findings of the skull in NF1 include mainly due to mesenchymal dysplasia rather than and lambdoidal sutural defect etc. The findings are neurofibromata (Figure 10a,b,c,d). Cystic angiomatosis In this entity, endothelial lined spaces representing lytic areas are seen throughout the skeleton. These may be vascular, lymphatic or both. Multilocular cystic lesions are noted predominantly in the axial skeleton. In the skull, multiple lucent areas are seen. With the suspicion radiographs of other bones are

Figure 10a: Figure 10b: NF involving left orbit taken to confirm the diagnosis (Figure 12a,b). and frontal bone. suture on the left. NF – Oval defect in the lambdoid

Figure 12a: Figure 12b: Cystic

Multiple lucencies in the Multiple angiomas Figure 10c: Plexiform Figure 10d: skull.Cystic angiomatosis – inangiomatosis the pelvic bones - including proximal sign on left. femora. neurofibromatosis with NF – Empty orbit spheno-orbital dysplasia. Vol. 4 | Issue 1 | January - March 2016 45 changes in the skull. Other entities of Phacomatosis do not have significant granulomainfants; 2. Hand-Schuller-Christianencountered at any age. (HSC) Radiographic disease Mucopolysaccharidosis (MPS) seen in children and young adults; 3. Eosinophilic This is a group of lysosomal disorders with absence as geographical skull are noted in HSC disease (Figurefindings in 14a,b). the skull In include eosinophilic large lytic granuloma areas described which can be encountered at any age solitary or multiple of specific enzymes in each entity. A specific diagnosis lytic areas are noted. Often it shows a bevelled edge featurebased on along the skull with findings frontal may bossing be difficult. scaphocephaly However, due to unequal involvement of the outer and inner andin Hurler calvarial syndrome thickening a “J” (Figure shaped 13).sella Hand is a prominent and spine cortices of the skull (Figure 14c). radiographs confirm the diagnosis.

Figure 13:

shaped sella and (a) (b) scaphocephaly.Hurler’s – “J”

Figure 14a,b: Langerhan’s cell histiocystosis (Large lytic areas described as geographic skull).

“J” Shaped sella Figure 14c: prominent sulcus chiasmaticus. nonsclerotic borders J shaped sella-flattened tuberculum sellae with a andEG of bevelled skull with edge. Causes of J-shaped sella: Normal variant in 5% of normal is markedly depressed (w or omega shaped sella), children; Optic chiasm glioma-if chiasmatic sulcus Sarcoidosis due to downward pressure of an enlarged third tumour may be bilateral; Chronic hydrocephalus- Involvement of the skull bones is rare in sarcoidosis. dysplasia.ventricle; Mucopolysaccharidosis - Hurler syndrome; noted. Achondroplasia-Neurofibromatosis-sphenoid However, multiple non-specific lytic lesions are Craniostenosis are primary (Due to premature Infections closure of the sutures) and secondary (causes), Systemic infections involving the skull are quite rare. Pyogenic bacterial , unifocal or Rickets, hyperthyroidism, ; ii. multifocal may manifest as lytic lesions. Clinical secondary craniostenosis are listed i. Metabolic- is staphylococcus (Figure 15a). Inborn errors of metabolism-MPS syndromes; iii. findings clinch the diagnosis. The common organism Hematalogical-sickle cell anaemia,thalassemia, Tuberculous osteomyelitis of the skull is also rare. shuntedspherocytosis; hydrocephalus. iv. Malformations of brain- It generally involves frontal and parietal bones. A microcephaly, holoprosencephaly; v. Iatrogenic- draining sinus may often be noted. Radiologically, Inflammatory lesions

there are no specific characteristics (Figure 15b). Langerhan’s cell Histiocystosis and sarcoidosis. Fungal infections of the skull generally produce Langerhan’sInflammatory cell lesions histiocytosis involving consistthe skull of include three groups, which are 1. Letterer Siwe’s disease seen in (Figure 15c). diffuse osteosclerosis with very little lytic changes 46 Journal of Medical and Scientific Research Figure 15a: Multifocal osteomyelitis Figure 15b: Tuberculous staphylococcal osteomyelitis. osteomyelitis. – Multiple small lucent areas in

Figure 17: parietal bones. Craniotabes – Rickets - Softening of frontal &

Hypophosphatasia It is a heritable autosomal recessive disorders of bone metabolism. In the infantile form, radiograph of

Figure 15c: Later in childhood, craniostenosis may be noted. mycoses. the skull shows deficient mineralization (Figure 18). Fungal osteomyelitis - Actino and Madura Parasitic infestations

Figure 18: Infantile skull are quite rare. However, if correlated with hypophosphatasia Echinococcus (hydatid) infestations involving the mineralization of the the diagnosis is possible. Radiologically, a sharply – Note poor the findings noted in the liver, lung and kidneys, skull bones. defined, expanding and lytic area is often a common finding (Figure 16a,b).

Hereditary hyperphosphatasia - autosomal recessive This is due to failure to replace immature woven bone with mature lamellar bone. Mabry syndrome

Although the entire skeleton may be involved the (a) (b) skull- Mental radiographs retardation are characteristic with hyperphosphatasia. with thickening Figure 16: and spherecial areas of bone sclerosis resembling bone. Paget disease (Figure 19). Hydatid cyst of skull – a. Parietal bone, b. Frontal

Metabolic disorders Common metabolic disorders that may involve the skull include nutritional rickets, hypophosphatasia Figure 19: and hyperphosphatasia. Hyperphosphatasia

woolly appearance simulating– Thick skullPaget’s. with encountered in certain areas. Although, growing ends Rickets due to vitamin “D” deficiency is still rickets, mainly in the frontal bone (Figure 17). of bones are affected, skull also may show features of Vol. 4 | Issue 1 | January - March 2016 47 Endocrinal influences on skull radiographs Hyperparathyroidism: This may be benign adenoma or carcinoma of the parathyroids resulting in hyperparathyroidism. Clinically and radiologically characteristic features are noted. In the skull, with pepper and salt appearance is a common feature (Figure 20a). Occasionally, lytic (a) (b) areas of varying size may be noted (Figure 20b). Figure 21a: Figure 21b: Acromegaly

due to pituitary gland tumor. calvarium, prognathia. Acromegaly – Enlarged sella – enlarged sella, thick Enlarged sella Figure 20a: syndrome; Intracranial hypertension; Pituitary Pepper and salt appearnace in tumours; Craniopharyngioma.– differential diagnosis: Empty sella hyperparathy roidism. Small sella may be normal but below mentioned - disorders may show small sella: Normal variant; (a) Hypopituitarism; Microcephaly; Myotonic

Cockayne syndrome; Dystrophia myotonica. dystrophy; Prader-willi-lambert syndrome; Sturge-Weber syndrome Figure 20b: Osteoporosis This is due to leptomeningeal venous malformations and multiple brown be ipsilateral to facial nevus or bilateral. The hemi tumors. with gyriform subpial tramline calcifications. It may

(b) classicalcranium of on this the entity affected (Figure side 22a,b). may be a little small in size. However, the intracranial calcifications are

Renal osteodystrophy as the name denotes is the radiological changes, which are osteoporosis, due to chronic renal insufficiency resulting in and secondary hyperparathyroidism. , osteosclerosis, soft tissue calcifications, Radiologically, the skull may show areas of osteosclerosis with brown tumors (Figure 20c). (a) (b)

Figure 22a,b:

Gyriform tramline calcifications. Figure 20c: Hemolytic anaemias Renal osteodystrophy These are majorly of two types. One is thalassemia with multiple lytic and sclerotic areas. (Table 7) and the second sickle cell anemia.

Table 7: mentioned. Thalassemia skull – Radiological findings are l Widening of dipole (Figure 23)

Next end l Thinning of outer table skull is hyperpituitarism, resulting in features of l Obliteration of outer table acromegaly.ocrinal Radiologically, disorder that the sellacommonly is often affects enlarged. the l Hypermedullosis The calvarium bones are thick with prognathism l l Obliteration of air sinuses (Figure 21a,b). “Hair on end” or “brush border”

48 Journal of Medical and Scientific Research Figure 27:

Figure 23: area with a button sequesterumLymphoma – Lytic Diploic thickening. Thalassemia –

Metastases à calvaria Sickle cell disease à 10% of all metastatic lesions affect the Thickening of the diploe of skull bones is noted. But, à Blastic lesions < 10% à 90% -- lytic lesions (Figure 28) the paranasal sinuses are not affected (Figure 24). à à Lytic- Tyroid and breast (Figure 29) Mixed – breast and GI malignancies Figure 24: à Neuroblastoma - Mixed lesions (Figure 30) Thickening of parietal Blastic- Prostate and carcinoid (Figure 31) boneSickle with cell anemiahair on -end appearance. Figure 28: Metastases from carcinoma breast.

Calvarial lesions – Neoplastic malignant Multiple myeloma (Figure 25a,b). Variable pattern of including punched out areas are noted.

Figure 29: Metastases from Leukaemia (Figure 26) – Osteoporosis with Moth- carcinoma thyroid. Eaten appearance is noted. sclerotic lesions are noted. Lymphoma (Figure 27) – Rare mixed osteolytic and

Figure 30: Metastasis from neuroblastoma (a) (b) with splitting of the sutures. Figure 25: a. Multiple myeloma, b. Multiple punched out lucencies with rain drop appearance.

Figure 26: Figure 31: Sclerotic Metastasis from carcinoma Leukemia – Moth- the parietal bone. prostate. Eaten appearance in

Vol. 4 | Issue 1 | January - March 2016 49 Toxic Radiological findings – Lytic, sclerotic and à Fluorosis mixed à Lead poisoning à Active (osteolytic) osteoporosis circumscripta à Hypervitaminosis D 33a). à Osteolyticin skull (large and well sclerotic defined phase. lytic lesion) (Figure most common cause is endemic water intake which à Osteosclerotic phase with cotton wool Fluorosis – 1932 caused by the following factors. The appearance of skull and diploic widening (Figure 33b). containsIngestion exceeding amounts of fluorine. à Water à Food à Tonic Figure 33a: à Wine Paget’s lytic phase (Osteoporosis à Therapy circumscripta).

Inhalation à à à Industrial - Cryolite, Al, Glass, Enamel Fertilizer - Superphosphate Figure 33b:

Addiction - Methoxyfluorane phase with basilar impression.Paget’s – Sclerotic (FigureRadiological 32a,b). findings include dense bones with calcification of ligaments and muscular attachments

Conclusion Conventional radiographs of the skull are rarely Figure 32a: taken at the present time, since CT and MRI play bones and occipital a major role in neuroradiology. However, several tuberosityFluorosis – simulating Dense systemic disorders and traumatic situations demand . skull radiographs. The container is also important in studying the contents. A variety of disorders

with various radiological features. reflecting on the skull radiographs are described Acknowledgements

Figure 32b: Hyderabad. Departments of radiology, NIMS & KREST Museum, petroclinoidFluorosis –ligament. Dense bones and calcified Conflicts of interest

RAuthoreferences declares no conflicts of interest. Miscellaneous – Paget’s 1. Subbarao Kakarla, Radiology of the Skull, Paras medical à deformans 2. www.radcharts.org/Skull/Skull.html. à Chronic bone disorder with excessive abnormal publishers, Hyderabad, India – 2006. bone remodelling à Pelvis (often asymmetric) à Skull

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