Ultrastructural morphology and cellular differentiation in acinic cell carcinoma.

Acinic cell carcinomas, in some instances, contain a component of intercalated duct cells. However, the manner in which this element is integrated within the more obvious acinar cells, as well as the role neoplastic intercalated duct cells play in determining morphologic patterns in acinic cell tumors, has not been fully investigated. Ultrastructural study and immunostaining with antibodies to cytokeratins and to S-100 protein carried out in nine cases of parotid acinic cell carcinoma suggest two basic differentiation patterns.

Salivary gland components involved in the formation of squamous metaplasia.

Squamous metaplasia is not an uncommon feature of a number of salivary gland lesions. Arterial ligation of rat submandibular and sublingual salivary glands was used for study of the processes and cell types involved in the development of the squamous metaplasia that occurs in ischemic and infarcted portions of gland parenchyma 6 to 8 days following vessel ligation. Light and electron micrographs show that the principal portion of salivary gland tissue undergoing squamous metaplasia is the acinar-intercalated duct cell complex.

Trypsin digestion in immunoperoxidase staining.

The effect of trypsin digestion on the immunoperoxidase-PAP staining of paraffin sections from normal and abnormal tissue was studied. Trypsin treatment reduced background staining considerably, but enhanced specific staining. Results were, therefore, much easier to read.