Invertiertes Papillom

Schneiderian papillomas, also known as sinonasal papillomas, are benign sinonasal tumors that arise from the Schneiderian epithelium of the nasal cavity and paranasal sinuses.

Epidemiology

Schneiderian papillomas account for ~2.5% (range 0.4-4.7%) of sinonasal tumors .

Pathology

There are three distinct histological types :

  • inverted papilloma (most common, ~50-80%)
  • exophytic papilloma (~20-50%): synonyms and superseded subtypes include transitional cell papilloma, fungiform papilloma, squamous papilloma, Ringertz tumor, and everted papilloma
  • oncocytic papilloma (~5%): superseded subtypes include cylindrical cell papilloma and columnar cell papilloma

Radiographic features

Schneiderian papillomas appear as abnormal soft tissue within the nasal cavity and/or paranasal sinuses. Inverted and oncocytic papillomas usually arise from the lateral nasal wall or paranasal sinuses (usually maxillary or ethmoid). Exophytic papillomas usually arise from the lower anterior nasal septum. With more extensive disease, there may be paranasal sinus opacification and bony structure expansion or even pressure erosion.

Treatment and prognosis

The inverted and oncocytic types of Schneiderian papilloma carry a 5-15% risk of malignant transformation to carcinoma (most commonly squamous cell carcinoma, but other types have been described as well). The exophytic papilloma type has essentially no malignant potential.

History and etymology

It is named after Schneiderian epithelium, which itself was named for Conrad Victor Schneider (1614-1680), a German anatomist and physician from Wittenberg, Germany .