Case 128 - Discussion

Uploaded: 2007-10-25, Updated: 2007-11-28

 

 

Mucicarmine CKAE1/3

CEA EMA
CK7 CK20
 

GCDFP-15

 
Paget's Disease of the Scrotum

The Key Features

  • Foreign cells in the epidermis;

  • PAS-D +, mucicarmine +;

  • Intra-epidermal apocrine origin: GCDFP-15+, CK7+, CEA+, EMA+;

  • Association with underlying adenocarcinoma: especially CK20 or CA19-9+.

CLINICAL FEATURES
 
  • Eczematoid, red, pruritic, slow-growing;
  • Extramammary locations: axilla, labia majora, scrotum, perineum;
GROSS FINDINGS
 
  • Circinate, annular, erythematous, eczematoid plaque
MICROSCOPIC FINDINGS
 
  • Foreign epithelioid cells in the epidermis just above the basal layer; in single, in rows, small nests/clusters, or gladular;
  • Often see a cleft-like separation between the Paget's cells and the adjacent normal epithelial cells;
  • Tumor cells are round or oval with pale, amphophilic cytoplasm that is commonly vacuolated;
  • Nuclei contain dispersed or vesicular chromatin;
  • The involved epidermis commonly exhibits hyperkeratosis and acanthosis that mimics SCC.
DIFFERENTIAL DIAGNOSES
 
  • Superficial spreading melanoma: S100+;
  • Bowenoid intraepidermal SCC: CK7-.
IMMUNOHISTOCHEMISTRY AND SPECIAL STAINS
 
  • Intra-epidermal apocrine origin: GCDFP-15 +, CK7+, CEA+, EMA;
  • If CA19-9 or CK20+, should rule out association with adenocarcinoma in the rectum, urinary bladder, or endocervix;
  • Positive for PAS-D, mucicarmine and Alcian blue in 50-60% cases;
TREATMENT AND PROGNOSIS
 
  • Surgical resection but may be very difficult.
REFERENCES
 
  • AFIP, nonmelanocytic tumors of the skin, series 4;
  • Rosai and Ackerman's Surgical Pathology, 9th edition.