Basal cell adenocarcinoma

Basal cell adenocarcinoma, abbreviated BCAC, is an uncommon malignant salivary gland tumour.

Basal cell adenocarcinoma
Diagnosis in short
Basal cell adenocarcinoma. H&E stain.
LM	unencapsulated lesion with basal-like cells, tubular component - within basal component, dense hyaline stroma around tumour cells
LM DDx	adenoid cystic carcinoma, basal cell adenoma - cannot be differentiated on cytology
Site	salivary gland - usu. parotid gland
Signs	salivary gland mass
Prevalence	very rare
Prognosis	good

It should not be confused with basal cell carcinoma, a very common tumour of the skin.

General

• Very rare.
• Malignant.
• Good prognosis.
• May arise from a basal cell adenoma.

Gross

• Usually in the parotid gland ~90% of cases.

Microscopic

Features:

1. Lesion is not encapsulated - key feature.
2. Basal-like cells:
   • Basophilic cells - key feature.
   • Usually in nests.
     • May be bilayered tubules or trabeculae.
   • Large basophilic nucleus.
   • Minimal-to-moderate eosinophilic cytoplasm.
3. Stromal cells.
   • Plump spindle cells without significant nuclear atypia.
     • Stromal cell nuclei width ~= diameter RBC.
   • Dense hyaline stroma.
4. Tubular component.
   • Within basal component, may be minimal.

DDx:

• Adenoid cystic carcinoma.
• Basal cell adenoma - encapsulated.
• Basaloid squamous cell carcinoma.

Images

• 

  BCAC - intermed. mag. (WC/Nephron)

• 

  BCAC - high mag. (WC/Nephron)

• 

  BCAC - high mag. (WC/Nephron)

www:

• Basal cell adenocarcinoma - intermed. mag. (webpathology.com).
• Basal cell adenocarcinoma - high mag. (webpathology.com).

IHC

Features:

• CK7 +ve (strong).
• S100 +ve/-ve.

See also

• Salivary glands.
• Head and neck pathology.