PSEUDOSARCOMA OF THE LARYNX - THE VALUE OF PLOIDY ANALYSIS

An 82-year-old male presented with a two-month history of hoarseness. A 2 cm pedunculated lesion was removed from the base of his epiglottis . Microscopy showed a polypoid atypical spindle cell lesion. Multiple levels failed to reveal an invasive squamous cell carcinoma. On the ba sis of haematozylin and eosin stained sections the main differential d iagnosis was a pseudosarcoma with an overlying dysplastic squamous muc osa or infiltrating spindle cell carcinoma. Immunohistochemistry showe d positive staining for vimentin but no convincing staining with antib odies to cytokeratin and EMA. Ultrastructural analysis also failed to reveal epithelial characteristics. Ploidy analysis by static cytophoto metry of the spindle cell proliferation revealed an aneuploid stem lin e with a DNA index of 1.67. On the basis of this the process was felt unlikely to be reactive and a diagnosis of a spindle cell squamous car cinoma was made. This diagnosis was subsequently supported by a clinic al recurrence of the nodule at a six-month follow-up.