Syringomatous carcinoma: A report of 2 cases

The diagnosis of syringomatous carcinomas is hampered by their rarity and their histologic resemblance to some metastatic adenocarcinomas from internal organs. In an attempt to verify if distinguishing histologic criteria between these two different classes of lesions could be provided, we compared the histopathologic findings of two additional cases of syringomatous carcinoma with those of six cases of metastatic adenocarcinomas to the skin from different internal organs. These latter were chosen on the basis of their syringomatous pattern. All cases examined exhibited substantially similar histopathologic features, namely, tubular structures with a tadpole appearance, cords and strands of squamous, basaloid or clear atypical epithelial cells, PAS-positive endoluminal secretive material, and sclerotic stroma. These results indicate that a precise diagnosis of syringomatous carcinoma is exceedingly difficult on histopathologic ground alone and should be offered only after that a careful physical examination and a substained follow-up have ruled out the existence of a primary carcinoma in any other organ.