Mixed Tumour (Chondroid Syringoma)

Epidemiology and Etiology:

• M > F

Common sites:

• Head and neck

Gross features:

• Solitary dermal nodule
• 1-3cm
• Slowly-growing

Histologic features:

• Epithelial and stromal elements with a wide spectrum of patterns
• Analogous to mixed tumours of the salivary gland
• Well-circumscribed
• Epithelial elements:
• Branching tubules
• Solid cords
• Islands
• Single cells
• Apocrine differentiation sometimes
• Eosinophilic cuticles within tubules sometimes
• Follicular differentiation in some
• Clear cell change maybe
• Plasmacytoid cells with hyaline-like cytoplasm in 40% (hyaline cells)
• Stroma
• Myxoid, chondroid, and / or fibrous
• Combinations usually
• Usually > ½ of lesion
• Osteoid components maybe

Immunophenotype:

Marker:	Sensitivity:	Specificity:
CK (inner layer)
CEA (inner layer)
EMA (inner layer)
S100 (outer layer)
Vimentin (outer layer)
Alcian blue (hyaluronidase resistant)

Molecular features:

Other features:

• Benign, no tendency for local recurrence

References:

• WHO Pathology and Genetics of Skin Tumours (2006)