Plastic Surgeon, the United Oxford Hospitals ; lately Senior Registrar, Department of Plastic Surgery, St Thomas's Hospital

Transcription

1 PRETIBIAL MYX(EDEMA With Report of a Case of Recurrence after Excision and Grafting By T. J. S. PATTERSON, F.R.C.S. Plastic Surgeon, the United Oxford Hospitals ; lately Senior Registrar, Department of Plastic Surgery, St Thomas's Hospital PRETIBIAL myxoedema, stated by Dunhill (I935) to be " interesting rather than serious, although it is annoying to the patient," occurs in 3 per cent. of patients with thyrotoxicosis (Trotter and Eden, I942). It is a disorder with which many surgeons are not familiar; most of the published cases have been described by dermatologists. The purpose of this paper is to report two further cases in one of which surgical treatment was undertaken. Most writers state that the first description of this condition was given by Watson-Williams (I895). He describes in detail a case of thyrotoxicosis with localised swelling of the legs, but refers to a previous case report by Hektoen. Ludwig Hektoen (I895) of Chicago wrote a paper on " Hyperplastic Persistent Thymus in Exophthalmic Goitre." In this he describes a case of thyrotoxicosis in which " the tissue over the anterior aspect of the lower third of each leg is swollen, elastic, like myxoedema, and a little tender on pressure." At necropsy " the subcutaneous tissue appears of a light yellow colour, and is infiltrated with a homogeneous, semi-solid, mucoid material." This is clearly a case of pretibial myxoedema and, if this is the one to which Watson-Williams refers, the credit for the first description should go to Hektoen. 2Etiology.--Pretibial myxoedema is due to the deposit of mucin in the skin of the legs. The mechanism is unknown. It has been thought that it may have a common cause with exophthalmos in hypersecretion of the thyroid-stimulating hormone of the anterior pituitary (Chandler and Hartfall, I952), although there is little evidence for this. Gilliland and Strudwick (I956) found that there is no direct correlation between the level of circulating thyroid-stimulating hormone and the presence of exophthalmos. They conclude that thyroid-stimulating hormone alone is not the cause of exophthalmos but that some other factor which may also be of pituitary origin is involved (Gilliland, I956). Pretibial myxoedema and exophthalmos do, however, run a similar course ; they often develop together and may both get worse after thyroidectomy (White, I956). Trotter and Eden (I942) state that pretibial myxeedema is always associated with past or present thyrotoxicosis ; half the cases appear before and half after treatment of the thyrotoxicosis. Inch and Rolland (I953) report one case where both pretibial myxoedema and exophthalmos developed in a patient under treatment for generalised myxoedema. Pretibial myxoedema occurs in 3 per cent. of patients with thyrotoxicosis, usually with toxic diffuse goitre. The average age of patients is 45 and the male-female ratio is I to 1.8 (Trotter and Eden, I942). 3 c x97

2 198 BRITISH JOURNAL OF PLASTIC SURGERY Clinical Features.--The deposit of mucin occurs in the skin of the anterolateral aspect of the lower half of the leg, causing a swelling which does not pit on pressure. It is usually bilateral from the first and always becomes so. Later the swelling extends round the limb, up to the knee and on to the dorsum of the foot. The skin is dusky, pink, or faintly brown, and there may be marked growth of coarse hairs. The dilated dimpled hair follicles produce an appearance resembling pigskin (Spence, 1953) (see Fig. 2). Histology (see Fig. 4).--The histological picture is similar to but more pronounced than that of generalised myx~edema. In the corium the collagen bundles show separation and partial degeneration owing to excessive deposits of mucin (White, 1956). Cases vary in severity (see Figs. 2 and 5) and there is also variation in individual cases from time to time. Willcox (1956) described a severe case in which considerable fluctuations of body weight were largely due to changes in the pretibial myxoedema. Symptoms are slight in most cases. There is some aching if the swelling is gross. The main complaint is of appearance and, where the feet are involved, of difficulty in fitting shoes. The course of the disease is variable but Trotter and Eden (1942) conclude that most cases run a fluctuating course unaffected by treatment and tending to disappear over several years. Treatment.--The majority of cases do not respond to any form of treatment, although improvement may occur spontaneously or, occasionally, following thyroidectomy (White, 1956). Dunhill (I937) described seven cases, in six of which the swelling disappeared after thyroidectomy ; in the seventh, an old man, the condition was improved. It is very much more common, however, for the swelling to occur first, or to become worse, after thyroidectomy. Inch and Rolland (1953) reported temporary improvement with cortisone. Thyroid by mouth and other endocrine treatment has no effect. Hyaluronidase may produce temporary softening but there is no permanent effect. No form of physiotherapy influences the condition except elastic bandaging which may be of benefit in limiting the swelling. Although medical treatment is ineffective, symptoms are usually mild and surgical treatment is only rarely required. Watson and Pearce (1949) reported one case in which the swelling increased gradually for seven years after thyroidectomy until the patient was incapacitated and amputation of the leg was carried out. O'Leary (I93 o) reported one case in which small areas were excised to improve the appearance. No detailed accounts have been found in the literature of excision of large masses of this tissue such as was carried out in Case 2 below. CASE REPORTS Case 1.--Mrs A. J., aged 45- Primary thyrotoxicosis with fairly extensive thyrotoxic myopathy. Her eyes had been prominent for four months before operation (Fig. I). June I956.--Operation : Professor J. B. Kinmonth. Subtotal thyroidectomy. July I956.wSwelling appeared on the front of both legs. This came up rapidly over the course of three weeks and had the characteristic appearance of pretibial myxcedema. Exophthalmos was becoming worse.

3 PRETIBIAL MYXCEDEMA 199 FIGS. I to 3 Case I. Fig. I.--May I956. Thyrotoxicosis and exophthalmos before thyroidectomy. Fig. z.--october I956. Pretibial myxcedema of both legs and pitting (edema of the feet four months after thyroidectomy. Fig. 3.--October x956. Lymphangiogram--normal (by Professor J. B. Kinmonth).

4 "200 BRITISH JOURNAL OF PLASTIC SURGERY October Legs more swollen over a wider area and there is now pitting ~edema on the dorsum of the feet (Fig. 2). Lymphangiogram showed no abnormality (Fig. 3). Biopsy showed the appearances of cutaneous myxoedema (Fig. 4). Treatment by local injections of hyalase was tried without effect. FIG. 4 Case i, October i956. Biopsy of skin from the front of the leg. Skin and superficial layers of the dermis showing infiltration of the dermis by connective-tissue mucin. Stain : Alcian blue/van Gieson. Connective-tissue mucin stains greeny blue. Collagen stains red. i4o. March I957.--The condition of her legs is unchanged and she is having some difficulty in getting shoes to fit her. Case 2.--Miss E. S., aged 45. Referred to the Department of Plastic Surgery in I952 with very severe pretibial myxoedema (Fig. 5). In I946 she had had subtotal thyroidectomy for thyrotoxicosis. Exophthalmos had been present for six months before operation. One month after the operation she noticed some swelling of both legs below the knees, which gradually increased. Biopsy showed " circumscribed

5 PRETIBIAL MYXO~DEMA 20I myx~cdema." She had received thyroid tablets, a course of radiotherapy to the pituitary and local hyaluronidase without effect. Elastic bandaging produced some improvement, but the size of her feet prevented her wearing anything like a normal shoe. It was considered justifiable to attempt excision of the mass of tissue on the dorsum of the feet to allow shoes to be fitted. March I953 (Operation).--All abnormal tissue was removed from the dorsum of the left foot and toes and replaced by an intermediate-thickness graft from the left thigh. Histological report: Severe ~edema, fibrosis, and mucoid degeneration of the connective tissue of the skin. A Case 2, March FIG. 5 B Severe pretibial myxeedema. The foot was soundly healed in three weeks. Two weeks later a lumpy area was noticed on the dorsum of the big toe suggesting that the condition was recurring in the grafted area. Four months later all toes were involved and the dorsum of the foot was swollen. October I953 (Operation).--A similar excision was carried out on the right foot and replaced by a graft from the right thigh. Histological report : Severe collagen degeneration and mucinous infiltration of the dermis. At the same time a biopsy was taken across the edge of the graft on the left foot (Fig. 6). Part of the original donor area on the left thigh was swollen then and has remained unchanged to the present time (Fig. 7). Unfortunately it has not been possible to take a biopsy of this. Several observers, however, agree that this is a patch of localised myxoedema similar to that below the knee. Both feet are now swollen although the swelling has not increased since shortly

6 "202 BRITISH JOURNAL OF PLASTIC SURGERY FIG. 6 Case z. A, O c t o b e r Biopsy o f r e c u r r e n t swelling on t h e d o r s u m o f the left foot seven m o n t h s after grafting. T h e section passes t h r o u g h the edge of the graft a n d shows dense scar tissue b e n e a t h the graft a n d m u c i n o u s infiltration o f the dermis o f t h e graft. 3o. B,~ O c t o b e r H i g h - p o w e r view o f Fig. 6, A, s h o w i n g infiltration of the superficial layers of t h e d e r m i s w i t h connective - tissue mucin. Stain : Alcian b l u e ' v a n Gieson. 14o. A B

7 PRETIBIAL MYX(EDEMA 203 after the operation. With the aid of a pair of elastic stockings she is able to lead a reasonably active life (Fig. 8). FI~. 8 Fig. 8.--Case 2, Appearance four years after excision of myxcedematous tissue from the dorsum of feet and toes. DISCUSSION Excess of mucin in the skin is found in a proportion of cases of hypothyroidism, and in a proportion of cases of toxic goitre (pretibial myxoedema); apart from these two conditions it is virtually unknown (Trotter and Eden, I942). Confusion arises from the fact that the term "myxcedema" has been regarded as synonymous with hypothyroidism since it was first proposed by Ord (z878). William M. Ord, physician to St Thomas's Hospital, had five cases under his care suffering from " the 'cretinoid' affection occasionally observed in middle-aged women." At post-mortem examination on one of these the skin of the foot was found to contain fifty times as much mucin as the skin of noneedematous bodies. He regarded this as an " essential condition" of the " cretinoid" affection and proposed the term "myxeedema," although he stated that " the name is only intended to represent the condition, and does not profess to involve an explanation of its causes." It seems that this must have been an exceptional case, for repeated investigations have since shown that excess of mucin in the skin is an uncommon feature

8 204 BRITISH JOURNAL OF PLASTIC SURGERY of hypothyroidism. Nevertheless the term has remained in common usage for cases of hypothyroidism, whether the skin contains excess of mucin or not (Spence, 1953). The distribution of pretibial myx(xdema suggests that gravity plays a part in its production (Wallace, I957), and the constancy of the site suggests a local factor. However, only a few cases are preceded by oedema, and congestive cardiac failure commonly occurs without the development of pretibial myx~edema (Trotter and Eden, 1942 ). In Case I, pitting oedema of the dorsum of the feet developed three months after the appearance of pretibial myxoedema (see Fig. 2). The cause of this is obscure, although it was thought that the pretibial myxoedema might be causing venous obstruction by increased tension of the subcutaneous tissues (Anderson, 1957). The lymphangiogram was normal (see Fig. 3). In Case 2 the appearance of localised myx~edema in the donor area suggests that trauma may play a part. One case reported by Trotter and Eden (1942) was that of a gardener who had suffered repeated minor injuries and who had numerous scars on his shins. It is difficult to see why only part of the donor area was affected. The distribution is similar to the hypertrophic scarring which may occur in the deeper patches in a donor area from which a graft of uneven thickness has been cut. SUMMARY The clinical features of pretibial myx~edema are described. Two further cases are presented. One typical case had a normal lymphangiogram. The second case was unusually severe, and excision and grafting of the involved skin of the feet was followed by recurrence in the grafted areas and in part of the donor area. Some mtiological factors are discussed. I would like to thank Dr H.J. Wallace for his continued help and encouragement in the preparation of this paper. Dr H. J. Anderson has kindly given me permission to include his patient (Case I) ; the lymphangiogram was carried out by Professor J. B. Kinmonth. The operative treatment in Case 2 was carried out in the Plastic Surgery Unit of St Thomas's Hospital. I would like to thank Dr F. N. L. Poynter, Librarian to the Wellcome Historical Medical Library, for his help in tracing the reference to Hektoen' s original paper. Dr I. IV. Whimster has prepared the histological material and I am most grateful to him for his help and for the histological reports. For the excellent illustrations I am indebted to Mr T. W. Brandon of the Department of Photography, St Thomas' s Hospital, who took the clinical photographs, and to Mr A. E. Clarke of the Department of Pathology, St Thomas's Hospital Medical School, who took the photomicrographs on Icicolor film.

9 PRETIBIAL MYXCEDEMA 205 REFERENCES ANDERSON, H. J. (I957). Personal communication. CHANDLER, G. N., and HARTFALL, S. J. (I952). Lancet, 1,847. DUNHILL, T. P. (I935)- Brit. reed. J., 2, Io34. (1937). Trans. med. Soc. Lond., 60, 234. GILLILAm3, I. C. (I956). Proc. R. Soc. Aged., 49, 212. GILLILAND, I. C., and STRUDWlCK, J. I. (1956). Brit. reed. J., x, 378. HEKTOEN, L. (1895). Int. reed. Agag., 4, 584 INCH, R. S. M. D., and ROLLAND, C. F. (1953). Lancet, 2, I239. O'LEARY, P. A. (I93o). Arch. Derm. Syph. N.Y., 2I, 57. ORb, W. M. (1878). Med.-chir. Trans., 61, 57- SPENCE, A. W. (1953). Brit. reed. ft., I, TROTTER, W. R., and EDEN, K. C. (1942). Quart. J. Aged., ti, 229. WALLACE, H. J. (1957). Personal communication. WATSON, E. M., and P~ARCE, R. H. (1949). Amer. J clin. Path., i9, 442. WATSoN-WILLIAMS, P. (1895). Clin. J., 7, 93. WHITE, R. H. R. (1956). Guy's Hosp. Rep., lo5, 2, 2o 5. WILLCOX, A. (I956). Trans. reed. Soc. Lond., 72, D