Squamous papilloma in the external auditory canal: A common lesion in an uncommon site

Figure 2 Histopathological findings (hematoxylin and eosin, × 200). Histopathological examinations revealed the characteristic features of hyperkeratosis, papillomatosis, parakeratosis, acanthosis and koilocytosis. Koilocytosis indicates diseased cells caused by human papilloma virus infection. Characteristic squamous cells containing peri-nuclear clearing with condensation of peripheral cytoplasm are the typical pictures of koilocytic cells. Irregular, raisin-shaped nucleus (short arrow) and bi-nuclei cells (long arrow) may be present.