Yasunobu Yasui

SMALL CELL UNDIFFERENTIATED CARCINOMA OF THE SUBMANDIBULAR GLAND : IMMUNOHISTOCHEMICAL EVIDENCE OF MYOEPITHELIAL, BASAL AND LUMINAL CELL FEATURES

A primary small cell undifferentiated carcinoma of the submandibular gland is reported. Histological studies revealed that the major part of this tumor was composed of cells slightly larger (10–14 μm) than lymphocytes. These tumor cells showed myoepithelial‐cell differentiation, which was confirmed by the immunohistochemical and ultrastructural findings. Furthermore, some of them showed luminal‐cell and basal‐cell differentiation immunohistochemically. However, there was no evidence of neuroendocrine differentiation. These findings demonstrated that the tumor had the features of all the salivary ductal components (myoepithelial , basal, and luminal cells) and supported that the tumor might arise from the salivary duct. Furthermore, it supports the hypothesis of multipotential stem cells as the origin for small cell undifferentiated carcinomas in salivary glands.

Tumoral calcinosis around the mandibular condyle

A case of tumoral calcinosis, occurring in the periarticular region of the temporomandibular joint of a 66-year-old Japanese man, is presented. The relevant literature is discussed.

Mechanical Contraction Property of the Levator Veli Palatini Muscle

Twenty adult dogs anesthetized with sodium pentobarbital were used as experimental animals in an analysis of the mechanical contraction properties of the levator veli palatini muscle. The following results were obtained: the contraction time and half relaxation time of maximal isometric twitch of the muscle were revealed to be 43 msec and 33 msec, respectively; a summation curve was obtained with stimulation at 15 Hz and maximal tetanic tension was at 70 Hz. The average of the tetanic tension ratio was found to be 5.7. The maximum rate of tension rise was observed at 150 Hz, and the value was twice the rate of the twitch contraction. The duration time of the active state plateau showed values of 3.9 to 4.5 msec. The contraction time of the levator veli palatini muscle closely resembles that of the intrinsic laryngeal and the orbicularis oris muscle.