Mucinous carcinoma

Mucinous carcinoma is an epithelial neoplasm that produces mucin.

Mucinous carcinoma can arise in a number of sites.

General

• Often have a better prognosis that tumours without mucinous differentiation.

Microscopic

Features:

1. Mucin - amphormous whispy or cream material.
2. Cytologically atypical cells within the mucin.
3. +/-Tumour without mucin.
   • Maximum amount acceptable depends on the primary site (see proportion of mucin section below).

Note:

• Mucin alone -- should prompt a search for atypical cells, i.e. levels should be done.

DDx:

• Benign mucocele.
• Adenocarcinoma with mucinous features.

Proportion of mucin

The criteria for diagnosing "mucinous carcinoma" varies by the anatomical site:

• Mucinous prostate carcinoma: > 25% of the tumour.
• Mucinous colorectal carcinoma: > 50% of the tumour.
• Mucinous gastric carcinoma: > 50% of the tumour.
• Mucinous breast carcinoma: > 90% of the tumour.
  • One source suggests: > 50% of the tumour.

See also

• Renal mucinous tubular and spindle cell carcinoma.