RESIDENT CASE STUDIES

September 25, 2003: Case 3 

Table of Contents | List of Diagnoses | Case 1 | Case 2 | Case 3 | Case 4 | Case 5

48 year old male with ethmoid cavity mass

Discussion by Karen Cline, DO

Inverted papilloma is a benign, but locally aggressive neoplasm occurring in the nose and/or paranasal sinuses.

Distribution: 30-50 year-old male>female

Microscopic Appearance: 

• Epithelial invaginations into the underlying stroma 5-30 layers thick with an epithelium that includes a combination of:
  • squamous--non-keratinizing squamous epithelium is the most common
  • ciliated columnar--appearance of normal respiratory mucosa
  • intermediate
  • mucus-secreting cells
• Neutrophils, often scattered throughout the epithelial layer as single cells, are microabscesses
• The stroma is variably fibrotic, vascular or edematous
• 8-14% of patients develop carcinoma
• There are no criteria to predict which papillomas will be followed by carcinoma.

Differential Diagnosis:

• Other types of Schneiderian papillomas
• Inflammatory Polyps--these have seromucinous glands in the stroma which are not present in the papillomas
• Squamous Cell Carcinoma-severe cellular atypia, partially cleared cytoplasm

References:

1. Demay, RM. (1996). The Art and Science of Cytopathology. Chicago, IL: American Society for Clinical Pathology Press.
2. Stephen S Sternberg et al. (Eds): Diagnostic surgical pathology, Volume 1, 3rd edition. Lippincott William & Wilkins.