N.P. Smith

Multinucleate cell angiohistiocytoma: an acquired vascular anomaly to be distinguished from Kaposi's sarcoma

Multinucleate cell atigiohistiocytoma is a newly described benign vascular condition that usually arises on the extremities of women over the age of 40 as discrete grouped violaceous erythematous papules, often mimicking Kaposis sarcoma. Of 10 patients, nine were women aged between 37–66 (average 51.5) years at the onset of their condition. The legs, and in particular the calves and thighs, were the commonest sites to be involved. However, in three patients the papules were confined to the back of the hands, and the male patient had lesions across the front of the chest. Bilateral lesions occurred in four patients. Histologically, the salient features were proliferation of capillaries and small venules at the level of the subpapillary plexus and the mid dermis, in association with prominent connective tissue cells and larger angulated multinucleate cells. Detailed histochemical and immunocytochemical studies have not elucidated the histogenesis of the multinucleate cells that seem to be a characteristic feature of this condition.

Solitary morphoea profunda

This study describes a series of patients with an unusual form of scleroderma. All five patients presented clinically with solitary, indurated plaques involving the upper trunk. Histologically the lesions were characterized by a dense, mononuclear cell infiltrate mainly in the subcutis, which was rich in plasma cells, and was associated with marked sclerosis and hyalinization of the connective tissue at this level. Lymphoid aggregates with germinal centre formation were present in three patients and tissue eosinophilia in one. No lesion has shown spontaneous resolution but neither has systemic involvement occurred, despite a maximum follow‐up of 17 years. Immunohistochemical studies revealed a mixed population of T and B lymphocytes with no evidence of immunoglobulin light‐chain restriction. We believe that the clinical and histological features in these five cases are sufficiently distinct to merit description under the title of ‘solitary morphoea profunda’.

Skin exudate levels of interleukin 6, interleukin I and other cytokines in mycosis fungoides

The role of locally released cytokines in inducing lymphocyte activation and infiltration in the skin lesions of mycosis fungoides has been investigated. The levels of selected cytokines were measured in chamber fluid samples from lesional and control skin. Biologically active interleukin 6 was significantly elevated in lesional samples and a recombinant form of this cytokine was shown to induce lymphocyte migration in an in vitro assay. Biologically active interleukin 1 was detected in all control chamber fluid samples. Significantly reduced levels of this cytokine were present in lesional samples, which may be the result of the release of preformed material. Interleukin 2 and tumour necrosis factor activity, and γ interferon and granulocyte macrophage colony‐stimulating factor immunoreactivity, were not detectable in any of the samples. Interleukins 1 and 6 may play a role in the pathogenesis of the lesional lymphocyte infiltrates in mycosis fungoides.

(2) Desmoplastic melanoma: a rare form of malignant melanoma that is usually mis‐diagnosed and mis‐managed

Pretibial epidermolysis bullosa (EB) is a rare variant of dominant dystrophic epidermolysis bullosa (DDEB) with distinct clinicopathological features. We have studied three families with this condition and one further case which was undiagnosed until the eighth decade of life. Clinical details of 25 other affected family members were obtained from the seven cases examined. All the families exhibited an autosomal dominant pattern of inheritance with a male preponderance of 2: i. The age of onset varied widely from 5 days to 25 years, but was consistent within families. The mean age for diagnosis of the probands was 42 years. Two patterns of clinical disease were observed. Cases with early onset disease (< i year) exhibited blistering and shearing of the skin in response to trauma of the lower legs during childhood. Cases with late onset disease (> 10 years) exhibited nail dystrophy with pruritic papulo-nodular lesions in the pretibial sites. Involvement of other sites was rare, apart from the presence of albopapuloid lesions in four of the seven cases examined. Subepidermal clefts were commonly seen in biopsies of involved skin even in the absence of blistering. Our data confirms that pretibial EB is a rare variant of DDEB with atypical clinical features which can cause considerable delay in diagnosis.