A rare case of recessive dystrophic epidermolysis bullosa and verruciform xanthoma.

A 33-year-old man with recessive dystrophic epidermolysis bullosa presented with a 3-month history of an enlarging mass within scarring on the posterior aspect of the right shoulder. The clinical appearance of the mass with an almost cobbled, verrucous surface, and its rapid evolution suggested the development of a squamous cell carcinoma (SCC) in a chronically scarred site. Histopathological examination of a biopsy taken from the lesion subsequently revealed it to be a verruciform xanthoma. This case shows that benign phenomena can mimic SCC and underlines the need for a biopsy to be taken promptly.

Chromoblastomycosis imported from Malta.

Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissues caused by pigmented fungi. It is primarily a disease of the tropics and subtropics. It is uncommon in the UK where it may occur as an imported disease. We describe a 42-year-old lady who developed chromoblastomycosis on her right forearm from Cladosporium, after visiting Malta. The lesion resolved after treatment with itraconazole for 6 months. To our knowledge there are no previous reports of chromoblastomycosis from Malta. We review the clinical course, diagnosis and management of this condition.

Malignant fibrous histiocytomas of the larynx--report of two cases.

Malignant fibrous histiocytoma of the larynx is a rare entity. It is even more infrequent for the tumour to arise from a specific location on the larynx namely the vocal cords. We report two cases of vocal cord malignant fibrous histiocytoma, one in a 27-year old man who underwent frontal partial laryngectomy, and the other in a 57-year old man who was managed with total laryngectomy. Both patients remain disease-free after 5 years of follow-up. We present a discussion of the available literature on this subject. As these tumours occur very infrequently, no one centre is able to acquire the prerequisite amount of experience to be able to lay down firm scientifically based guidelines on the management of these tumours. It is thus inevitable that whatever evidence we have is purely anecdotal in nature.

Cystic nodal metastasis in occult tonsil carcinoma--a case report.

A "branchial cyst" in a patient above 40 years old may turn out to be a malignant cystic nodal metastasis from a primary tumour in the tonsil. We present a case of a 45-year-old woman in whom an initial mistaken diagnosis of branchial cyst was made. The neck mass was discovered to be malignant and the left tonsil was subsequently implicated as the primary source. Older patients with cystic neck masses should be managed on the presumption that these may possibly be metastatic lesions from a primary oropharyngeal tumour.

Amelanotic superficial spreading malignant melanoma mimicking Bowen's disease.

A 67-year-old woman presented with a scaly, erythematous plaque, for which a clinical diagnosis of Bowen's disease was made. However, incisional biopsy established the diagnosis of amelanotic superficial spreading malignant melanoma. Biopsy thus avoided the use of inappropriate destructive therapy, such as cryotherapy or cautery. This case illustrates the importance of obtaining a histological diagnosis, prior to treatment, in suspected cases of Bowen's disease.

Regressing cutaneous lymphomas of T-cell and B-cell lineage.

We report two cases of regressing cutaneous lymphoma. The first case is a CD30-positive T-cell lymphoma with immunogenetic evidence of clonality. The second case is a diffuse large-cell non-Hodgkin's lymphoma of B-cell lineage in which clonality was established by immunogenetic analysis and in situ hybridization for light-chain mRNA.

Is poor prognosis really related to HLA-DR expression by malignant melanoma cells?

HLA-DR expression was examined in 50 consecutive primary cutaneous malignant melanomas with a Breslow depth greater than 2 mm using two well-characterized monoclonal antibodies which detect fixation-resistant epitopes. In 31 of these cases (62%) a subpopulation of tumour cells was reactive, although there was considerable heterogeneity. Positive labelling did not correlate with depth but was associated with a reduced likelihood of developing early metastatic disease and a tendency for better overall survival, particularly in male patients. These findings contrast with earlier studies using cryostat sections and one study on paraffin-embedded tissue in which HLA-DR expression was shown to be a poor prognostic factor, but are consistent with the findings in other malignant tumours studied. The significance of HLA-DR expression as a marker of prognosis may depend on the type of tissue preparation, the sensitivity of the immunocytochemical techniques used and the method of assessment.

The effect of capsule composition on the biocompatibility of alginate-poly-l-lysine capsules.

The encapsulation of islets of Langerhans in alginate-poly-l-lysine has been proposed as a method for the immunoprotection of transplanted islets. Although several capsule compositions have been reported, there has been no published study concerning the effect of capsule composition on the severity of the foreign body reaction. Empty capsules were prepared from high mannuronic acid alginate and were coated with: (1) poly-l-lysine alone, (2) poly-l-lysine plus high guluronic acid alginate, or (3) poly-l-lysine plus high mannuronic acid alginate. The capsules were placed in the renal subcapsular space or the peritoneal cavity, and retrieved after three weeks of histological examination. The recipients were WAG/01a, nude (athymic), diabetic BB, and non-diabetes prone BB rats. The severity of reaction to the capsules was determined by measuring the thickness of the pericapsular cell infiltrate or by a scoring system. The severity of the reaction to the capsules was strain-dependent in both the renal and peritoneal sites, with the BB and nude rats displaying the most severe responses. The degree of response was not affected by capsule composition in the renal subcapsular space, but in the peritoneum, the high mannuronic acid alginate capsules provoked the weakest response, and this type of capsule will be used for future transplantation work. The infiltrating cells were characterised by immunohistochemistry and electron microscopy and found to be mostly fibroblasts and macrophages.

Observer variation in the measurement of Breslow depth and Clark's level in thin cutaneous malignant melanoma.

We have assessed the degree of observer variation of both Breslow depth and Clark's level in a series of 50 thin malignant melanomas. Our findings are similar to those of previous international studies in the Breslow depth is the more reproducible measure. Significant intra- and inter-observer variation exists and in some cases it was up to +/- 0.86 mm. Even small differences will potentially affect patient management at our centre and this was analysed using kappa statistics. Good agreement was found between observers and this could be improved by comparing the mean of two or more measurements. This removes larger errors, but smaller observer errors and differences in subjective interpretation of the deepest malignant cell mean that agreement will never be more than 90 per cent. This is high compared with studies of observer variation in other pathological conditions, e.g., dysplasia of the cervix, but where surgical management is potentially disfiguring it is not high enough. We conclude that Breslow depth and Clark's level should not be the sole basis of wide excision protocols.

A study of the effect of capsule composition on the viability of cultured alginate/poly-l-lysine--encapsulated rat islets.

Islets of Langerhans were isolated from WAGola rats and encapsulated in high mannuronic acid sodium alginate droplets. The capsules were completed in the following ways: (a) poly-l-lysine alone, (b) poly-l-lysine plus high guluronic acid alginate, (c) poly-l-lysine plus high mannuronic acid alginate. Islet viability was assessed every 3-4 days over a period of 4 weeks, by a microfluorometric assay using fluorescein diacetate and propidium iodide, and every 7 days by perifusion. The perifusion results were corrected for DNA content to take islet size differences into account. The results from the microfluorometric assay showed a generally high viability of the islets in all groups at each time interval. The perifusion experiments showed that the response time and stimulation indices of the islets was similar in all groups, but the absolute amount of insulin released was slightly lower from encapsulated islets relative to unencapsulated controls. It was concluded that the presence of a capsule, regardless of its composition, did not adversely affect the membrane integrity of the islets, their response time, nor their proportionate increase in insulin release following glucose stimulation. However, the absolute amount of insulin released from encapsulated islets was reduced during perifusion. This reduction was apparent after 1 week in culture, but remained stable thereafter.

Can HLA-DR expression help in the routine diagnosis of malignant melanomas?

Two monoclonal antibodies, TAL-IB5 and LN3, directed at epitopes of HLA-DR were applied to a variety of benign naevi and malignant melanomas. Of the 31 naevi examined, 28 were completely unreactive. Weak staining was confined to a few cells in two intradermal naevi and there was more widespread reactivity in a halo naevus. Seven of the 25 primary cutaneous malignant melanomas were reactive with one or both of the antibodies and this reactivity was more marked in the deeper lesions. These positive cases were not felt to present diagnostic difficulties and it was concluded that TAL-IB5 and LN3 were not of use in distinguishing between benign and malignant melanocytic proliferations.