[Muir-Torre syndrome and Turcot syndrome]. / Syndrome de Muir-Torre et syndrome de Turcot.

INTRODUCTION: Lynch syndrome (LS) is a syndrome that carries a genetic predisposition to certain cancers associating, either in a single individual or in a family, a visceral tumour, mainly colorectal, with a high risk of other synchronous or metachronous cancers. LS is linked with mutations in the genes coding for proteins in the DNA repair system. Phenotypic variants of SL exist, including Muir-Torre syndrome (MTS) and Turcot syndrome (TS), both of which predispose to colorectal cancer. They may be distinguished by the presence of benign or malignant sebaceous tumours in MTS, and tumours of the central nervous system in TS. PATIENTS AND METHODS: A 59-year-old man, with a history of right colon cancer at the age of 36 years, consulted for a nose lesion shown by histopathological examination to be a sebaceous tumour. Immunohistochemistry revealed loss of expression of proteins MSH2 and MSH6, strongly suggesting a diagnosis of MTS. Eight years earlier, the man's son had developed a fatal glioblastoma; given the paternal phenotype of MTS, the hypothesis of TS in the son is probable. DISCUSSION: This case suggests that several variants of Lynch syndrome may be seen within the same family. It raises the issue of screening for cerebral tumours in patients with MTS and in their family members, even though such a recommendation does not exist; current recommendations in fact consist primarily of gastrointestinal and gynaecological monitoring.

[Chloroquine-induced achromotrichia. An ultrastructural study]. / Achromotrichie due A la chloroquine. Etude ultrastructurale.

BACKGROUND: Electron microscopy examination of scalp biopsies from a patient with chloroquine achromotrichia gave elements concerning the pathogenesis of chloroquine-induced achromotrichia. CASE REPORT: A 21-year old light brown-haired patient developed achromotrichia after four months of treatment with chloroquine for subacute lupus erythematosus. Hair bleaching completely regressed 5 months after discontinuing chloroquine despite replacement with hydroxychloroquine. During the achromatrichia phase, many ultrastructural anomalies were observed in the hair root melanocytes: the nuclei were small and densified, and there was an accumulation of immature melanosomes in the cytoplasm; these melanosomes, mainly in stage II, were rarely transferred to keratinocytes. After recovery from the achromotrichia, melanocytes displayed a normal aspect. DISCUSSION: Pathophysiological disturbances leading to chloroquine induced achromotrichia are still unclear. The ultrastructural study of hair follicles in our patient show that under chloroquine action melanocytes become unable to perform complete melanin synthesis and to produce normally melanized melanosomes which may be transferred to keratinocytes. Non-melanized or poorly melanized melanosomes accumulate in the melanocytes which finally become inactive cells. These findings suggest that achromotrichia is induced by a toxic effect of chloroquine on the melanocyte.

Stage-related decrease in natural killer cell activity in untreated patients with mycosis fungoides.

Natural killer activity of peripheral blood mononuclear cells against the human cell line K 562 was evaluated in 11 patients with mycosis fungoides and simultaneously in 10 age- and sex-matched controls. In the patient group, nine had no previous treatment and in two topical therapy had been discontinued more than 3 months before. None had any associated disease or concurrent therapy that could interfere with the immune system. Patients with early disease showed a mean specific lysis and a range of individual data similar to the controls whereas patients with advanced disease had a significant defect of natural killer activity at effector: target ratios of 100 : 1, 50 : 1, and 25 : 1, as shown by the Mann-Whitney test. Preincubation of effector cells with alpha-interferon for 1 h in a single patient with low natural killing capacity led to a clear increase of the specific lysis, suggesting reduced functional activity rather than depletion of effector cells.