L. C. Fuller

Serum S‐100 protein: a potentially useful prognostic marker in cutaneous melanoma

S‐100, an acidic calcium‐binding protein, is present within cells of neuroendocrine origin. Its value in the immunohistochemical diagnosis of tumours of melanocytic origin is well established. More recently, a potential role has been proposed for the serum concentration of this protein as a marker of metastatic melanoma disease activity. In the present study, the concentration of serum S‐100 protein was measured in 97 patients with histologically proven malignant melanoma who were attending a dermatology and/or oncology department for the follow‐up of their disease. Serum S‐100 was also measured in 48 control subjects without malignant melanoma. The clinical stage of the patients was classified according to the criteria of the American Joint Committee on Cancer into stages I‐IV. The median (range) serum S‐100 protein concentration was significantly higher in stage I (0·11 (0·1–0·21) μg/L, P<0·001), stage II (0·11 (0·05–0·22) μg/L, P<0·001), stage III (0·24 (0·07–0·41)μg/L, P<0·0001) and stage IV (0·39 (0·06–15·0)μg/L, P<0·0001) compared with the control group (0·1 (0·05–0·15)μg/L). At a threshold value of 0·2μg/L, the sensitivity and specificity for detection of advanced disease were 82% and 91%. respectively. Thus serum S‐100 protein may be a valuable prognostic marker for malignant melanoma and for monitoring therapy. Serum S‐100 protein concentration was also compared with the Breslow thickness of the tumours. There was a significant correlation between these variables (n=72. rs=0·32, P<0·01). Combining a serum S‐100 threshold value of >0·22μg/L and a Breslow thickness of >4mm improved the sensitivity and specificity for the presence of secondary spread to 91% and 95%, respectively. Therefore, a combination of both baseline serum S‐100 protein and Breslow thickness may provide a better indication of the prognosis at diagnosis.

Cutaneous Rosai–Dorfman disease

We report a patient with purely cutaneous Rosai–Dorfman disease (RDD) who presented with a solitary, asymptomatic plaque on the back of her left thigh, with characteristic, large histiocytoid cells exhibiting emperipolesis histologically. Cutaneous lesions occur in 27% of patients with lymph node involvement in RDD however purely cutaneous disease has only been reported on 18 previous occasions. The aetiology is unknown, although it is thought to be a reactive disorder rather than neoplastic, possibly an immunological response to an infectious agent.

Scalp ringworm in south‐east London and an analysis of a cohort of patients from a paediatric dermatology department

Summary Background Scalp ringworm or tinea capitis has become an increasingly important public health issue in the past decade in Great Britain. Recently, certain dermatology departments in London have seen a large increase in tinea capitis in all its forms.

Screening for asymptomatic carriage of Trichophyton tonsurans in household contacts of patients with tinea capitis: results of 209 patients from South London.

Background  There is currently an epidemic of tinea capitis in urban areas of developed countries caused by Trichophyton tonsurans. Recurrence or re‐infection with dermatophyte is not uncommon after adequate oral treatment. Asymptomatic carriers who are household contacts may partly explain this observation by forming a reservoir for infection.

Fixed drug eruption following metronidazole therapy and the use of topical provocation testing in diagnosis.

Summary Fixed drug eruption is characterized by recurrent well‐defined lesions appearing in the same location each time the drug responsible is taken. A number of agents have been implicated. Metronidazole, a nitroimidazole agent widely used for its antibacterial and antiprotozoal activity, has been reported only rarely as the causative agent. We describe a patient with FDE due to metronidazole in whom we were able to induce the clinical and histological features of FDE by topical provocation testing. In agreement with the published literature we commend the use of topical provocation testing as a possible first‐line investigation in the diagnosis of FDE. This may avoid the need for subsequent oral provocation testing and therefore the prevention of possible adverse sequelae.

Sebaceous gland hyperplasia, human immunodeficiency virus and highly active anti‐retroviral therapy

keratin 10 is not expressed in suprabasal keratinocytes of the palmoplantar epidermis. Therefore, if a patient with EHK shows no palmoplantar involvement, it should be better to screen for keratin 10 first rather than keratin 1; our patient showed no palmoplantar involvement. The interesting feature seen in our patient was that there was no facial involvement, although keratin 10 is expressed in suprabasal keratinocytes of the face. To our knowledge, there have been no previous reports of EHK that have shown a lack of facial involvement. It is not yet understood why the face is not involved in our patient. This finding suggests a special nature of the facial skin in EHK, because the seborrhoeic areas including the face, where sebaceous glands are rich, have some barrier functions. Alternatively, the p.L153V mutation found in our patient may show a unique morphology on the face. Further studies on a larger number of EHK patients should characterize the facial involvement and the genotype– phenotype correlation.

Trends in the presentation of cutaneous malignant melanoma over three decades at King's College Hospital, London

The aim of this study was to examine trends in the presentation of cutaneous malignant melanoma at Kings College Hospital (KCH) over the last three decades (1970–2000). KCH was one of seven centres that participated in the 1987 Cancer Research Campaign (CRC) publicity campaign aimed at promoting earlier self‐recognition of melanoma. Data included patient age at presentation, sex, tumour site, Breslow thickness and histological subtype. The late 1980s saw a threefold increase in the annual number of melanomas and an eightfold increase in thin melanomas compared to the 1970s. The increase occurred in both sexes and was particularly marked after the CRC campaign but numbers had already begun to increase prior to this. The increase has predominantly been thin (Breslow < 1.5 mm) tumours of the superficial spreading variety with a resultant fall in mean Breslow thickness. There has been a decline in the annual number of melanomas since the peak in 1992 which is not explained by increased proportion of in situ tumours. The CRC campaign may have contributed to the documented increase in thin tumours but this trend had begun prior to 1987 suggesting factors other than public awareness and earlier presentation are important. It is encouraging that the number of melanomas has declined over the last 5 years at KCH but it is yet to be seen whether this reflects a real decrease in the incidence of melanoma.

A novel case of linear syringomatous hamartoma

A 4‐year‐old girl presented with a linear, indurated area of dusky erythema and hyperpigmentation down the left leg, present since birth. Histology suggested syringomata. The clinical course and appearances suggest a novel entity for which we have coined the term ‘linear syringomatous hamartoma’.