tnical R_adiologY (1980)31, 313-315 ~ 1980 Royal ~:ouege oi rtadiologists

ftlberculosis of the Skull Vault T. S. BROWN, P. P. FRANKLYN and M. S. K. MARIKKAR

Bradford Royal Infirmary and St Luke's Hospital, Bradford

Tuberculosis o f the skull vault is very rare and recently has only been reported from Africa. Two cases have preselated in the city of Bradford during the past 10 years, both in young Asians. The radiology is discussed.

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Skeletal tuberculosis is rare, occurring in about 1% of all patients with tuberculosis (Davidson and Horowitz, 1970). Tuberculosis of the skull is very rare, occurring in only one of 176 cases of bone and joint tuberculosis reported by Nicholson (1974); Tirona (1954) reported an incidence o f 0.4%. 1)anziger et al. (1976) however encountered nine cases over seven years and found involvement of the skull second only to that o f the vertebrae.

The incidence o f tuberculosis in the indigenous population of developing countries is falling; patterns of tuberculous disease in the developing world persist when residents from these countries migrate to developed countries (British Thoracic Association 1978). Recent case reports (Barton, 1961; Prinsloo and Kirsten, 1977) describe tuberculosis of the vault of the skull in the local African population. Bradford has a large Asian population, and consequently many less common manifestations o f tuberculous disease are observed.

We have not found any previous case reports o f tuberculosis o f the skull arising in the United Kingdom. We therefore report two cases observed in this city in the past 10 years.

CASE REPORTS

Case 1. An Asian, R.Z., aged six years, presented with fever of one months duration, cough for one week and one episode of haemoptysis. He had associated loss of appetite. On examination, a fluctuant swelling was present on the left side of the scalp and enlarged lymph nodes in several fields. Mycobacterium tuberculosis was found in pus aspirated from the scalp swelling. Chest X-ray examination showed a right- sided pleural effusion with consolidation of the medial segment of the middle lobe. A skull X-ray showed a punched- out destructive lesion in the left frontal bone with a second, tess well-defined destructive lesion in the same bone (Fig. 1).

Case 2. R.P., an Asian boy aged 16 years, presented with a PaLnless swelling over the left frontal bone, following minor head injury. On examination the swelling was fluctuant. A second lesion was present over the left parietal bone and another non-tender fluctuant swelling was found overlying the sternum.

Chest X-ray showed massive mediastinal adenopathy (Fig. 2) and a skull X-ray (Fig. 3) demonstrated a destructive

Fig. 1 - Case 1. Skull film showing a clearly punched-out lesion in the left frontal bone, and a much smaller, less well- defined lesions is seen just lateral to the sagittal suture in the left frontal bone.

lesion in the left frontal bone abutting on, but not crossing, the coronal suture. The lateral xerogram (Fig. 4) clearly shows the soft tissue swelling (Pott's puffy tumour) overlying the frontal bone and evidence of periosteal reaction. No destructive bone lesion is observed.

DISCUSSION

The ages o f our patients conform to the previously reported series; 75 -80% of cases occur under the age o f 20 years (Strauss 1933; Meng and Wu, 1942). Trauma has been suggested as a cause in several cases,

314 C L I N I C A L R A D I O L O G Y

Fig. 2 - Case 2. Lateral chest X-ray showing a large mass of glands in the anterior mediastinum.

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Fig. 4 - Lateral xerogram showing a large soft tissue swelling overlying the frontal bone (Pott's puffy turnout) with an associated periosteal reaction.

Fig. 3 - Case 2. A well-defined, punched-out destructive lesion is shown in the left frontal bone, adjacent to the coronal suture.

and certainly drew attention to the soft tissue swel. ling in our second ease. Meng and Wu (1942) challenged the significance of trauma and this view was reinforced by Barton (1961), none of whose cases had a history o f preceding injury.

A primary tuberculosus lesion o f the skull is rare, as other foci can usually be demonstrated most frequently, as in our cases, in the chest. Meng and Wu (1942) reported the bones and joints as the most frequent sites of secondary tuberculous lesions. Goldblatt and Cremin (1978) reported skull involve- ment in two patients with multiple bone lesions, but pointed out that isolated involvement of the skull may occur.

Radiologically, the earliest lesion of bone is an area o f iU-defmed rarefaction, as in the smaller lesion o f our first case. As the lesion matures it assumes a more clearly defined punched-out appearance; tan- gential views at this time may reveal a break in the cortex. Lesions may be multiple, coalesce and cross suture lines (Danziger et aL, 1976). The frontal and parietal bones are involved more frequently than other areas of the skull (Brailsford, 1944). Perfora- tions o f the outer cortex usually causes a fluctuant soft tissue swelling (Port's puffy tumour). Inward

TUBERCULOSIS OF THE SKULL VAULT 315

c^,ation rarely results in meningitis or cerebral eflo l

-ess (Straus, 1933; Meng and Wu, 1942). abs~ Our second case is o f great interest, in that perio- steal reaction was associated with the soft tissue

-"hag and this does not seem to have been reported ore, though Meng and Wu (1942) reported two of

their cases as starting from the periosteum. Seque- stration may be seen within the destructive lesions, a~d has been referred to as bone sand. The diagnosis is confirmed by the demonstration of tubercle bacilli and if negative, serological examination should exclude syphilis and yaws (Barton, 1961). The response to specific anti-tuberculous therapy is good and may confirm the underlying cause (Barton,

1961). A wide differential diagnosis must be considered in

the absence of lesions elsewhere. Radiologically this would include histiocytosis-x, and post-traumatic lepto-meningeal cyst. An intradiploic dermoid is sequestered by suture lines (Danziger et al., 1976). To this list might be added primary or secondary turnours. The appearance o f osteoporosis circum- sedpta is unlikely to cause much confusion, as skull vault tuberculosis is extremely rare in older age groups.

Clinical confusion might arise with such conditions as sebaceous cysts, cephalhaematoma, or possibly a lipoma of the scalp. Very rarely non-specific or fungal 0steomyelitis of the skull may cause confusion.

REFERENCES

Barton, C. J. (1961). Tuberculosis of the vault of the skull. British Journal of Radiology, 34, 286-290.

Brailsford, J. F. (1944). The Radiology of Bones and Joints, 3rd edn. J. & A. Churchill London.

British Thoracic Association (1978). Tuberculosis among immigrants in Britain. Memorandum from the Joint Tuberculosis Committee. British Medical Journal, 1, 1038-1040.

Danziger, J., Bloch, S., Cremin, B. J. & Goldblatt, M. (1976). Cranial and intra-cranial tuberculosis. South African Medical Journal, 50, 1403-1405.

Davidson, P. T. & Horowitz, I. (1970). Skeletal tuberculosis. A review with patient presentation and discussion. American Journal of Medicine, 48, 77-84.

Goldblatt, M. & Cremin, B. J. (1978). Osteo-articular tuber- culosis: its presentation in coloured races. Clinical Radiology, 29, 669-677.

Meng, C. M. & Wu, Y. K. (1942). Tuberculosis of the fiat bones of the vault of the skull. A study of forty cases. Journal of Bone and Join t Surgery, 24, 341 - 353.

Nicholson, R. A. (1974). Twenty years of bone and joint tuberculosis in Bradford. A comparison of the disease in the indigenous and Asian populations. Journal of Bone and Joint Surgery, 56B, 760-765.

Prinsloo, J. G. & Kksten, G. F. (1977). Tuberculosis of the skull vault. A case report. South African Medical Journal, 51,248-250.

Straus, D. C. (1933). Tuberculosis of the flat bones of the vault of the skull. Surgery, Gynaecology and Obstetrics, 57, 384-398.

Tirona, J. P. (1954). The roentgenological and pathological aspects of tuberculosis of the skull. American Journal of Roentgenology, 72, 762-768.