RESIDENT CASE STUDIES

October 16, 2003: Case 2 

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

Nine year old boy with right neck mass

Discussion by Karen Cline, DO

Benign tumor with differentiation toward the matrix of the hair follicle.

Distribution:

Occurs most commonly in the head and neck of young people in the first two decades of life.

Gross Appearance: Sharply demarcated mass ranging in size from 0.5-3 cm with a variegated gray, white, brown cut surface.

Microscopic Appearance: 

• Composed of islands of two cell types: basophilic cells and eosinophillic shadow cells.
• The basophillic cells are at the periphery of cell islands with:
  • little cytoplasm
  • hyperchromatic nuclei
  • mitoses.
• The basophillic cells transition, either gradually or suddenly, into eosinophillic shadow cells toward the center of the island. 
• These cells are characterized by:
  • more cytoplasm
  • distinct cell borders
  • no nuclear staining.
• Other findings may include calcification, which can ossify in older tumors, and a foreign body giant cell reaction ocuring when the cell islands break off and go through the connective tissue stroma.

Diagnostic Criteria

• islands of basaloid cells and ghost cells

Differential Diagnosis:

• Basal cell carcinoma

References:

1. Stephen S Sternberg et al. (Eds): Diagnostic surgical pathology, Volume 1, 3rd edition. Lippincott William & Wilkins.