Encapsulated Papillary Carcinoma

Encapsulated Papillary Carcinoma

Encapsulated papillary carcinoma occurs as a well-circumscribed mass, usually located in the central breast below the nipple. Many cases are associated with nipple discharge.

The carcinoma consists of delicate papillae with thin fibrovascular cores. The cells are often columnar in shape and monotonous in appearance.



  • Encapsulated papillary carcinoma (EPC)


  • Intracystic papillary carcinoma

  • Encysted papillary carcinoma


  • Papillary carcinoma present within single well-circumscribed cystic space



  • Incidence

    • 0.5-2% of breast cancers in women

      • Rare in men but more common than invasive ductal carcinoma or DCIS

  • Age

    • Most common in elderly women (median: 70 years)


  • Often presents as palpable mass or circumscribed mammographic density

    • Location is usually central below nipple

    • Usually deeper in breast than large duct papillomas

  • Some women present with nipple discharge

Natural History

  • EPC was originally classified as DCIS

    • Lymph node metastases are rare

    • Macrometastases have been reported in rare cases; associated carcinomas are often exceptionally large

    • Cases of isolated tumor cells in nodes may be related to epithelial displacement by prior core needle biopsy

  • Survival is > 95% at 10 years

  • Although absence of myoepithelial cells is more compatible with classification as invasive carcinoma, clinical behavior is more similar to DCIS


Histologic Features

  • Carcinoma is confined to well-circumscribed space

  • Outer capsule is generally fibrotic with scattering of lymphocytes

    • Entrapment of epithelium within capsule may occur

  • Delicate thin papillary fronds with thin fibrovascular core

  • Fronds are lined by single layer of monotonous-appearing columnar cells

  • Occasional globoid cells may be present

    • More abundant pale cytoplasm and rounded in shape

    • Often positive for GCDFP-15

    • Should not be misinterpreted as myoepithelial cells

  • Approximately 25% of cases are associated with areas of frank stromal invasion

    • Invasive carcinoma extends beyond fibrous capsule of lesion

    • Carcinoma is generally of no special type and is not papillary in appearance



  • Estrogen and progesterone receptors are positive in almost all cases

  • HER2 is absent

  • Myoepithelial markers will confirm absence of myoepithelial cells in papillary fronds and in surrounding capsule

    • p63 is most useful marker for detecting myoepithelial cells in papillary fronds

    • Endothelial cells often lie close to tumor cells and will also be positive for muscle markers (e.g., smooth muscle actin, calponin)

  • Collagen type IV is present around periphery of lesion


Ductal Carcinoma In Situ, Papillary Type

Jul 6, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Encapsulated Papillary Carcinoma

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