PERINEURAL TUMOUR SPREAD: AN UNUSUAL CAUSE OF CARPAL TUNNEL SYNDROME

I. R. MACKAY and J. M. BARUA

From the Department of Plastic Surgery, Dundee Royal Infirmary

We describe the development of the carpal tunnel syndrome in a 5%year-old man, from perineural spread of a previously-excised cutaneous malignancy. Journal ofHand Surgery (British Volume, 1990) 15B: 104-105

Carpal tunnel syndrome is common and has been associated with systemic conditions such as rheumatoid disease, hypothyroidism and diabetes mellitus (Le Quesne, 1978) as well as localised conditions such as osteochondroma (Nather, 1986; Tompkins, 1967). Evers- mann (1982) has summarised the indication for operative treatment as failure of conservative therapy with recur- rence of symptoms after a four to eight week period in a dorso-ulnar gutter splint. We report a case in which perineural spread from a previously-excised squamous carcinoma in an index finger presented three years later as a case of carpal tunnel syndrome. The patient subsequently underwent above-elbow amputation, biop- sies having shown perineural involvement to within 5 cm of the elbow. The implications of this case are discussed.

Case report

A 58-year-old unemployed coal-carrier was seen in February 1982 with a large fungating tumour on the radial side of the proximal phalanx of his right index finger (Fig. 1). Prior to being seen, he had failed to attend nine times over the preceding 14 months. The patient’s right index finger was amputated under general anaes- thetic and two lesions were excised from the dorsum of his right hand. Histologically, the lesion of the index finger was a well-differentiated squamous cell carci-

Fig. 1 Fungating tumour on the index finger when the patient is first seen.

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noma and the lesions from the dorsum of his hand were both areas of Bowen’s disease (intra-epidermal squamous cell carcinoma).

He failed to attend for review but, three years after his amputation, he was referred again complaining of altered sensation in his right thumb and thenar eminence of three months’ duration. He had wasting of the thenar eminence and weakness of thumb opposition. A clinical diagnosis of carpal tunnel syndrome was made and confirmed by nerve conduction studies which demon- strated a prolonged distal latency in keeping with median nerve compression in the carpal tunnel.

The patient was subsequently admitted for release of his right carpal tunnel. At operation the median nerve was found to be hard and fibrosed in appearance. The fibrosis did not appear to extend into the forearm. Biopsies of the perineural tissue were taken and later reported as showing mature fibrous tissue extensively infiltrated with moderately differentiated squamous cell carcinoma.

The patient failed to keep his post-operative review appointments and, when he eventually attended two months later, his hand was painful and tender with fibrosis of the palmar skin and contracture of the middle and ring fingers. He had no regional lymphadenopathy. He was admitted for distal forearm amputation. Frozen sections showed squamous cell carcinoma extending along the median nerve to within 5 cm of the elbow, necessitating an above-elbow amputation.

At present, the patient remains apparently free of disease, although he does suffer severe phantom limb pain.

Discussion

Perineural spread of tumour is well recognised (Willis, 1973). We have, however, been unable to find any previous reports of carpal tunnel syndrome being caused by perineural spread of cutaneous squamous cell carci- noma. Early operative treatment is more likely to lead to a complete recovery in carpal tunnel syndrome (Semple, 1969). Trial splintage may delay treatment, as may the length of waiting lists. In our case, the patient’s failure to attend was the problem. Perhaps earlier operation would have permitted a lower level of amputation. We recom- mend urgent operative exploration of patients with a

THE JOURNAL OF HAND SURGERY

PERINEURAL TUMOUR SPREAD CAUSING CARPAL TUNNEL SYNDROME

past history of cutaneous malignancy who develop carpal tunnel syndrome.

Acknowledgement We express our sincere thanks to Mr .I. H. Stevenson for his advice and encouragement in the reporting of this case and also to Mr _I. Kirk, his predecessor, who initially managed the patient.

References EVERSMANN, W. W. Entrapment and Compression Neuropathies. In: Green,

D. P. (ed.) Operatiae Hand Surgery. New York, Churchill Livingstone Inc., 1982: 957.

Le QUESNE, P. M. (1978). The Carpal Tunnel Syndrome. British Journal of Hospitai Medicine, 20: 155-164.

NATHER, A. and CHONG, P. Y. (1986). A Rare Case of Carpal Tunnel Syndrome due to Tenosynovial Osteochondroma. Journal of Hand Surgery, 118:3:47&480.

TOMPKINS, D. G. (1967). Median Neuropathy in the Carpa! Tunnel Caused by Tumour-like Conditions. Journalof Bone and Joint Surgery, 49A: 4: 737- 740.

WILLIS, R. A. The relationship Between Tumours and Nerves. In: Willis, R. A. The Spread of Turnours in the Human body; (3rd edn). London, Butterworths, 1973: 121-125.

SEMPLE, J. C. and CARGILL, A. 0. (1969). Carpal-Tunnel Syndrome. Results of Surgical Decompression. Lancet, I: 918-919.

Accepted: 4th May 1989 Mr. I. R. Mackay, Department of Plastic Surgery, Dundee Royal Infirmary, Barrack Road, Dundee, DDI 9ND.

0 1990 The British Society for Surgery of the Hand

02667681/90/0015-0104i$10.00

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