Epithelioid leiomyoma of the larynx.

We describe the pathological features of a case of laryngeal epithelioid leiomyoma (leiomyoblastoma) which, to our knowledge, is the second case to be reported in the world literature. A review of the literature confirmed that leiomyoma as such is a very rare neoplasm in the larynx, and only 33 cases have been previously reported. The neoplasm was located in the left vocal cord and consisted of mainly epithelioid, round or spindle-shaped cells, often with clear cytoplasm, which were arranged predominantly in solid nests and sheets. The tumour cells showed positive immunoreactivity for smooth muscle actin and desmin. The tumour showed low mitotic activity and immunostaining with MIB 1 (Ki-67) accordingly revealed the occasional cell only to be positive, confirming a low proliferative activity in agreement with a benign neoplasm. Epithelioid leiomyomas located in other sites have been shown to act occasionally in a malignant fashion, and the necessity for careful long-term follow-up of the patient is therefore emphasized.

Incidence of Down's syndrome in Sweden during the years 1968-1977.

The incidence of Down's syndrome has been studied among children born in Sweden during the years 1968-1977. The risk for mothers of different ages of bearing such a child did not change during these years. This does not exclude that a change in incidence might have occurred in smaller areas of the country but escaped detection for statistical reasons. A higher than expected number of children with Down's syndrome were born in a few communities, which most likely is a chance event. No correlation could be detected between the incidence of Down's syndrome and a number of socioeconomic variables. The correlation with maternal age was studied in detail. There was a significant excess of males among both the newborn children with Down's syndrome and fetuses with trisomy 21 aborted after prenatal diagnosis. A similar tendency was found among the cases with a chromosome mosaicism but not among those with a translocation. Two hypotheses are put forward to explain the excess of males with trisomy 21.