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SUMMARY We examined the effect of incisional biopsy on the subsequent histology of 15 benign melanocytic naevi. In all cases the histology of the residual lesion within the second specimen was unchanged apart from the presence of a surgical scar, and in general the definitive excision specimen showed a reduction in melanocytes at the dermo-epidermal junction overlying the scar. In no case were there any features suggestive of melanoma.

Summary Schwannomas are benign encapsulated tumours arising from the sheaths of peripheral nerves. They present as slowly enlarging solitary lumps, which may cause neurological defects. Multiple lesions are rare, but occur in patients with neurofibromatosis type 2 or schwannomatosis. Positive outcomes have been reported for surgical excision in solitary schwannomas. However, the role of surgery in patients with multiple lesions is less clear. The risk of complications such as iatrogenic nerve injury and the high likelihood of disease recurrence mean that surgical intervention should be limited to the prevention of progressive neurological deficit. We report a case of a 45 year old male who presented with multiple enlarging masses in the upper limb and sensory deficit in the distribution of the ulnar nerve. The tumours were found to be related exclusively to the ulnar nerve during surgical exploration and excision, a rare phenomenon. The masses were diagnosed as schwannomas following histopathological analysis, allowing our patient to be diagnosed with the rare entity segmental schwannomatosis. One year post-operatively motor function was normal, but intermittent numbness still occurred. Two further asymptomatic schwannomas developed subsequently and were managed conservatively.

Eosinophilic pustular folliculitis is a rare disorder previously reported predominantly in Japanese people who are otherwise healthy. Recently, the disorder has been noted in patients with acquired immune deficiency syndrome, as has eosinophilic folliculitis, a similar but distinct entity. The authors report a patient with eosinophilic folliculitis who was immunocompromised after high dose chemotherapy and bone marrow autograft for treatment of non-Hodgkin's lymphoma.

In primary cutaneous malignant melanoma, the vascularity of the dermis immediately deep to the lesion may relate to tumour aggressiveness and to prognosis. These newly formed dermal vessels are incorporated into the melanoma to form the tumour microcirculation. We have assessed the percentage vascular volume in a series of primary melanomas in order to investigate the relationship between tumour vascularity and maximum tumour thickness. For the 64 melanomas included in this study, there appeared to be a significant relationship between the percentage vascular volume and the maximum tumour thickness. This relationship was not influenced by the presence of necrosis, vascular invasion, regression, or lymphocytic infiltrate, nor by the growth phase of the tumour. However, the percentage vascular volume was very low in the occasional thick melanoma, at least one of which was associated with prolonged survival. It seems possible that a low tumour vascularity could correlate with a relatively favorable outcome in cutaneous melanoma.

Using Ulex europaeus I lectin (UEA1) to demonstrate endothelial cells, we have previously shown that frequency of capillary invasion correlates closely with maximum tumor thickness in primary cutaneous melanoma. UEA1 demonstrates both vascular and lymphatic capillaries; however, only vascular capillaries possess basement membranes. In order to ascertain whether these capillaries were lymphatic or vascular, we employed a double staining technique, using UEA1 in conjunction with a monoclonal anti-type IV collagen antibody. We studied 21 primary cutaneous melanomas. Seven of the 21 included lymphatic capillaries, while 14 did not. These lymphatic capillaries were very sparse and appeared to be residual dermal lymphatics rather than a result of lymphangiogenesis. Lymphatic permeation by melanoma was not seen in any of the tumors studied. There was no apparent association among tumor thickness, level of invasion, growth phase, necrosis, regression or mitotic index, and presence of lymphatics within the melanomas. Although scanty lymphatics are present in some primary cutaneous melanomas, this study does not suggest that lymphatic permeation plays a major role in the spread of melanoma to locoregional lymph nodes.

The role of vascular invasion as a prognostic indicator in melanoma has not been fully evaluated, mainly due to difficulty in differentiating between capillaries and artefactual spaces caused by shrinkage in routine histological sections. However, immunohistochemical staining using Ulex europaeus I (UEA-I) permits accurate identification of tumor capillaries, thus facilitating recognition of vascular invasion. Sixty-six primary cutaneous melanomas were included in this study. Sections of each case were stained with UEA-I; then, vascular invasion at the level of the tumor capillary bed was sought. Hematoxylin-and-eosin-stained sections were reviewed; the thickness of each lesion was measured and the level of invasion and the growth phase of the tumors were also assessed. The frequency of vascular invasion was found to increase with increasing tumor thickness and with increasing level of invasion. Vascular invasion was seen in only one of 29 horizontal growth phase melanomas, whereas it was identified in 28 of 37 vertical growth phase tumors. Although these results would seem to indicate that vascular invasion within melanomas is unlikely to be an independent prognostic variable, they may partly explain the deteriorating prognosis associated with increasing tumor thickness. They also lend support to the concept of "horizontal" and "vertical" growth phase in melanoma.

A novel method for grading intestinal metaplasia, with general applicability, is described. Highly significant agreement was found by kappa analysis both for intra-observer (k = 0.90) and for inter-observer (k = 0.85) variation, confirming the reproducibility of the method. The ranks derived by this method were correlated with gastric tissue levels of the enzymes beta-glucuronidase, lactic dehydrogenase (LDH), and %m-LDH. A significant (P less than 0.05) positive correlation was found between intestinal metaplasia and %m-LDH, but there was no correlation between intestinal metaplasia and beta-glucuronidase or LDH.

The vasculature of B16, a murine melanoma and Mel-mo, a human melanoma, was studied using intravital staining of patent capillaries by the fluorescent bisbenzamine dye Hoechst 33342. Capillaries were numerous at the edge of tumours in both the lines studied, but were scarcer within the nodules. Vascular volume as a proportion of total tumour volume was estimated by means of point counting. In both B16 and Mel-mo, the percentage vascular volume was inversely related to log tumour weight. Tumour necrosis, which increased with tumour size, was inversely correlated with percentage vascular volume, emphasizing the central under-perfusion of these experimental tumour nodules. This pattern of perfusion, with greater density of functioning capillaries at the periphery of tumour nodules, was seen in both the tumour lines examined despite differences in the degree and pattern of necrosis.