Carcinoma of the ear: a case report of a possible association with chlorinated disinfectants.

In this report we present a case of squamous cell carcinoma developing in a mastoid cavity after prolonged exposure to the chemical disinfectant, Eusol. The efficacy and safety of Eusol and other chloric acid (hypochlorous acid) derivatives in clinical use is debated.

Aggressive squamous cell carcinomas developing in patients receiving long-term azathioprine.

We report three patients who developed unusually aggressive squamous cell carcinomas after receiving long-term azathioprine treatment for dermatological disorders. Two patients gave a history suggestive of moderate to excessive sun exposure, and the third suffered from chronic actinic dermatitis. Hence, ultraviolet light damage may have been a significant cofactor in the development of these malignancies. Careful follow-up is necessary in patients who are taking azathioprine long term, and who have previously been excessively exposed to ultraviolet light (UVL), or in whom future exposure is likely to be excessive. We suggest that strict sun avoidance measures are followed by patients on long-term azathioprine, or that alternatives to azathioprine therapy are considered, especially in individuals inherently at risk of UVL damage, and in those already showing clinical signs of such damage.

Diaplacental induction by ethylnitrosourea of tumours at the pial border of the central nervous system in (T X HT)F1 mice.

Ethylnitrosourea (ENU) was diaplacentally applied to (T X HT)F1 mice at a dose of 40 mg/kg on different gestation days during organogenesis and early fetal stages by i.p. injection to the dams. The animals were particularly sensitive to induction of tumours at the central nervous system (CNS)-skull-vertebra interface (30 and 20% in ENU-treated male and female offspring respectively, compared with 1% in controls). ENU treatment during the late organogenesis stage (gestation days 8-11) proved to be less efficient in tumour induction than during the subsequent early fetal period (gestation days 12-14). Ninety-two per cent of the CNS tumours were located at the interface between the CNS and the osseous surrounding. The distribution of these tumours at the pial border was inhomogeneous: 69% were found at the brain-skull border, 6% of the tumours occurred within the cervico-thoracal districts and 25% within the lumbo-sacral districts of the spinal cord-vertebra interface. Histological classification revealed a preferential occurrence of neuroepithelial tumours in male offspring (approximately 20%) and only approximately 7% Schwann cell tumours and approximately 3% tumours of meningomesenchymal origin. In female offspring neuroepithelial tumours and Schwann cell tumours were observed at about an equal rate (9-10%), in contrast to meningo-mesenchymal tumours (1%). Nearly 98% of these tumours were situated at the basal districts of the space between the CNS-skull and spinal cord-vertebra. This indicates a particular sensitivity of the basal neurothelium, a derivative of neural crest cells, for ENU-induced carcinogenesis. The pluripotency of these cells during the mid-gestation period apparently enables growth of different histopathological tumour types, which arise independently from each other.

'Unicorn' among rats exposed to mycotoxins from Fusarium.

A horn-like nodule developed in the middle of the forehead of a white rat, exposed perinatally to T-2 toxin and to zearalenone, the secondary metabolites of Fusarium. The hard nodule consisted mainly of keratine, derived from a squamous carcinoma spreading through the nasal turbinals and invading the brain.

Radiation-induced carcinoma of the temporal bone.

A case of a patient in whom carcinoma of the right temporal bone developed 39 years after a series of injections of radium chloride is presented. Carcinomas of the temporal bone and paranasal sinuses are a complication of radium administered therapeutically or ingested accidentally by watch dial painters.