Multispectral classification techniques for terahertz pulsed imaging: an example in histopathology.

Terahertz pulsed imaging is a spectroscopic imaging modality using pulses of electromagnetic radiation (100 GHz-10 THz), and there has been recent interest in studying biomedical specimens. It is usual to display parametric images derived from the measured pulses. In this work, classification was achieved by applying multispectral clustering techniques to sets of parametric images. It was hypothesised that adequate information for clustering was carried in a small number of parametric images, providing these were weighted by complementary physical properties. Materials prepared for histopathological examination were chosen because their condition remained stable during long imaging periods and because their dehydrated state led to greater penetration of the radiation. Two specimens were examined in this pilot study, one of basal cell carcinoma and one of melanoma. Unsupervised ISODATA classification using three selected parametric terahertz pulsed images was compared qualitatively with k-means classification using the shape of the whole time series, and with conventional stained microscope slides. There was good qualitative agreement between the classifications. Classifications were consistent with the morphological appearances expected, but further work is required to determine if tumour discrimination is possible. The results have implications for the future development of the technique as the need for only a small number of features could lead to considerably reduced acquisition times.

Solitary fibrous tumour of the forearm. A rare tumour in an atypical site.

Solitary fibrous tumour (SFT) is a rare spindle cell neoplasm that usually arises from serosal surfaces. Although it is now increasingly recognized in extra-serosal locations, only two previous cases of SFT arising in an extremity have been reported. We describe another such case and review the literature regarding extra-serosal SFT.

Polymorphous low-grade adenocarcinoma of parotid gland.

A case of polymorphous low-grade adenocarcinoma arising within the parotid gland is described. This appears to be only the second case of this distinctive neoplasm to have arisen ab initio within a major salivary gland. It displayed the relatively indolent course associated with this adenocarcinoma subtype and emphasises that this diagnosis now has to be considered in tumours of major salivary glands.

Unilateral naevoid trichoepitheliomas on the face of a child.

Trichoepitheliomas are benign epidermal appendage tumours that present most commonly as solitary lesions, and less often as multiple, symmetrically distributed lesions on the face, scalp, neck and trunk. Only a few patients have been reported in whom trichoepitheliomas were found as unusually configured linear or plaque-like confluent lesions, all of which occurred in patients with skin types V or VI. We describe a white girl with a hemifacial plaque of confluent naevoid trichoepitheliomas, the first report of such lesions in a white patient.

Intestinal metaplasia in stilboestrol-induced vaginal adenosis.

We present an unusual case of vaginal adenosis with progressive intestinal metaplasia, previously undescribed, in a female patient exposed to stilboestrol in utero. Argentaffin cells were present within these areas, a feature not previously reported in benign vaginal adenosis. The development of the intestinal metaplasia coincided with the onset of a vaginal discharge so severe that, after 7 years, a vaginal resection was performed. Intestinal-type glands have been described in the cervix and ovary, almost invariably associated with malignancy. The possible role of intestinal metaplasia in the development of enteric-type neoplasms of the vagina is discussed.

Severe predominantly acral variant of angiokeratoma of Mibelli: response to long-pulse Nd:YAG (1064 nm) laser treatment.

The classification of vascular abnormalities is difficult. We describe a child with a disorder that is best described as angiokeratoma of Mibelli. This unusual, severe, predominantly acral case has been improved by long-wave Nd:YAG laser treatment, but treatment is still ongoing.

Calciphylaxis in the absence of renal failure.

We report a patient with severe bilateral leg ulceration that was resistant to treatment. A biopsy confirmed the cause as calciphylaxis. Calciphylaxis refers to a syndrome of calcium deposition in the small and intermediate dermal vasculature which can lead to epidermal ischaemia, ulceration and necrosis. Most cases occur in those with chronic renal failure and secondary hyperparathyroidism. We describe the rare presentation of calciphylaxis in a patient with normal renal function and primary hyperparathyroidism who had many classical features. Unfortunately she developed gangrene, sepsis and died.

Eosinophilic cellulitis following the lines of Blaschko.

Eosinophilic cellulitis is an inflammatory dermatosis of unknown aetiology. We describe a case following the lines of Blaschko, which may be the expression of cutaneous mosaicism, suggesting a possible underlying genetic predisposition for the development of Wells' syndrome.

A case of childhood dermatofibrosarcoma protuberans without detected cytogenetic abnormality.

Dermatofibrosarcoma protuberans (DFSP) is a rare, infiltrative skin tumour of intermediate malignancy, with a limited potential for metastasis but a high rate of recurrence; specific cytogenetic abnormalities are now known. Childhood DFSP has been considered a rarity in the past, but it is now recognized that many cases of childhood DFSP are diagnosed only in adulthood. Despite advances in the understanding of its pathogenesis as well as the development of valuable immunohistochemical and cytogenetic diagnostic techniques, there often remains a significant delay between the initial presentation and diagnosis of DFSP. We report a case of childhood DFSP in which the diagnosis was reached only after a nodular lesion developed in a plaque that was initially present. Causes for delay between initial presentation and diagnosis in childhood DFSP are discussed. Histology and immunostaining in our patient showed the typical features of DFSP, but the G-banded cytogenetic analysis of short-term tissue culture was negative. However, this technique offers only a detection rate between 50% and 80%. Clinicians should be aware of the limitations of newer diagnostic techniques. Increasing recognition amongst paediatricians and paediatric dermatologists that childhood DFSP is not as rare as once believed will probably lead to the use of newer diagnostic methods at an earlier stage, and so reduce the delay between the onset of symptoms and diagnosis.

Sweet's syndrome presenting as palmoplantar pustulosis.

Sweet's syndrome was initially described as a reactive dermatosis characterized by sudden onset of fever, leucocytosis, and raised erythematous plaques infiltrated with neutrophils, and therefore called acute febrile neutrophilic dermatosis. However, later it became obvious that fever and neutrophilia are variable features, and a number of other characteristics have been described. Although the dorsa of the hands are frequently affected, the palmoplantar involvement mimicking pustulosis observed in our case appears to be unusual.

The role of thyroid fine needle aspiration (FNA) cytology in a District General Hospital setting.

The pilot study was undertaken to evaluate the role of FNA cytology in the clinical management of patients with thyroid swelling, in a District General Hospital (DGH) setting. One hundred and eleven patients were investigated over a period of 3 years, with a total of 142 fine needle aspirations. Statistical analysis showed a sensitivity of 71%, a specificity of 91% and a false negative rate of 2.7%. These results compare very favourably with other institutions. This study therefore shows that thyroid nodule FNA cytology can be performed in a DGH with a high standard of diagnostic accuracy, the results of which play a key role in patient management.

Expression of c-erbB2 and p53 protein is similar in breast cancer from British and Japanese women.

In an attempt to explain the difference in outcome between British and Japanese women with breast cancer we have compared histopathological features, expression of c-erbB2 and p53 proteins and clinical outcome of 191 British (Anglo) women with 171 Japanese women treated between 1979 and 1980. The Japanese patients were significantly younger than the Anglo patients, while in premenopausal women the latter had significantly smaller tumors. The proportion of tumors expressing c-erbB2 and p53 proteins was similar in both populations. c-erbB2 positivity was significantly associated with positive lymph node status and with poorly differentiated carcinomas. Duration of relapse-free and overall survival was significantly longer in the Japanese women than in the Anglo women. Women with c-erbB2-negative tumors had a longer overall survival than women with c-erbB2-positive tumors and this difference was accentuated when patients were stratified according to country of origin. Japanese women with c-erbB2-negative tumors had the best outcome, whereas the Anglo women with c-erbB2-positive tumors had the worst. There was no relationship between p53 status and any histopathological features or clinical outcome. Differences in the expression of c-erbB2 and p53 do not explain the better outcome experienced by Japanese breast cancer patients.

Microbiological and molecular diagnosis of deep localized cutaneous infection with Trichophyton mentagrophytes.

We describe a healthy young woman with a localized deep dermal infection on the right side of the chest wall. It was caused by the dermatophyte Trichophyton mentagrophytes, and resolved after two pulses of oral itraconazole 200 mg twice daily for 1 week. As cultural and microscopic features did not enable a precise identification of the fungus, molecular investigation was undertaken. Patterns of HaeIII restriction digests of genomic DNA from the culture matched those from Arthroderma incurvata and A. benhamiae, which is the teleomorph of T. mentagrophytes var. mentagrophytes.