Myoid differentiation in vascular transformation of lymph node sinuses due to venous obstruction. Immunohistochemical and ultrastructural studies.

Five cases of vascular transformation of lymph node sinuses due to venous obstruction are described in this paper. Evidence was found in four cases to actin immunoreactivity, and involvement of myofibroblasts was electronmicroscopically observed in one case. Differential diagnosis of vascular transformation of lymph node sinuses is discussed. The lesion is similar to KAPOSI's sarcoma-like subcutaneous processes and to chemodectoma-like bodies in the lung.