Breast

Papillary carcinoma

Encapsulated papillary carcinoma


Editorial Board Member: Julie M. Jorns, M.D.
Deputy Editor-in-Chief: Gary Tozbikian, M.D.
Evan R.J. Goyette, M.D.
Kristen E. Muller, D.O.

Last author update: 14 September 2022
Last staff update: 14 September 2022

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PubMed search: Encapsulated papillary carcinoma breast

Evan R.J. Goyette, M.D.
Kristen E. Muller, D.O.
Page views in 2021: 16,908
Page views in 2022 to date: 14,809
Cite this page: Goyette ERJ, Muller KE. Encapsulated papillary carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/breastmalignantencapsulatedpapillary.html. Accessed October 1st, 2022.
Definition / general
  • Expansile papillary tumor, occurring in postmenopausal women, with low or intermediate grade nuclei surrounded by a fibrous capsule that lacks myoepithelial cells along the papillae and at the periphery or shows focal peripheral myoepithelial staining
Essential features
  • Papillary tumor comprised of delicate papillary fronds with fibrovascular cores lined by cuboidal to columnar epithelial cells with low to intermediate grade atypia, often within a cystically dilated duct surrounded by a thick fibrous capsule
  • Lacks myoepithelial cells along the papillae and around the periphery of the tumor or only focal peripheral myoepithelial staining
  • Staged as ductal carcinoma in situ (DCIS) (i.e., Tis) in the absence of invasive carcinoma, due to indolent behavior and excellent prognosis
  • Encapsulated papillary carcinoma (EPC) with high grade cytologic atypia and increased mitotic activity are rare; they are best classified as high grade invasive breast carcinoma with features of EPC and staged as an invasive carcinoma
Terminology
  • Intracystic papillary carcinoma (not recommended)
  • Encysted papillary carcinoma
ICD coding
  • ICD-O:
    • 8504/2 - noninfiltrating intracystic carcinoma
    • 8504/3 - intracystic carcinoma, NOS
  • ICD-11:
    • 2E65.Y & XH9XV2 - other specified carcinoma in situ of breast & noninfiltrating intracystic carcinoma
    • 2C6Y & XH0GT6 - other specified malignant neoplasms of breast & encapsulated papillary carcinoma with invasion
Sites
Pathophysiology
Etiology
  • Unknown
Diagrams / tables

Images hosted on other servers:

Myoepithelium and hormone receptors in EPC

Clinical features
Diagnosis
  • Histologic examination of tissue removed by biopsy or surgical excision
Radiology description
  • No distinct imaging findings can distinguish between subtypes of papillary carcinomas (AJR Am J Roentgenol 2012;198:264, Front Surg 2022;8:743881)
  • Imaging does not distinguish encapsulated papillary carcinoma (EPC) with and without invasion beyond the capsule (Breast J 2019;25:539, Breast J 2021;27:209)
  • Mammography:
    • Circumscribed to lobulated, round to oval mass
    • May have irregular, angulated or multilobulated borders
    • Calcifications uncommon
  • Ultrasound:
    • Hypoechoic solid mass, sometimes with cystic component
    • Color Doppler often highlights prominent vascular supply
  • Magnetic resonance imaging (MRI):
    • Well defined, round to oval, heterogeneous mass with varying signal intensity depending on cystic fluid content
Radiology images

Contributed by Mariel Molina Nunez, M.D. and Julie Jorns, M.D. (Case #518)
Mammogram of the left breast mass

Mammogram of the left breast mass

Ultrasound view of the complex mass

Ultrasound view of the complex mass



Images hosted on other servers:

Mammographic, sonographic and MRI findings


Mammographic findings

Mammographic findings

Prognostic factors
Case reports
Treatment
Gross description
Gross images

Images hosted on other servers:

Papillary tumor within cystic space

Solid tumor within cystic duct

High grade EPC with hemorrhage

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Kristen E. Muller, D.O. , Mariel Molina Nunez, M.D. and Julie Jorns, M.D. (Case #518)
Encapsulated papillary carcinoma with invasion

Encapsulated papillary carcinoma with invasion

Synaptophysin

Synaptophysin

EPC, circumscribed with fibrous capsule EPC, circumscribed with fibrous capsule

EPC, circumscribed with fibrous capsule

Low grade nuclear atypia Low grade nuclear atypia

Low grade nuclear atypia


EPC with invasion EPC with invasion

EPC with invasion

EPC with DCIS and invasion

EPC with DCIS and invasion

High grade EPC High grade EPC

High grade EPC

Estrogen receptor (ER)

Estrogen receptor (ER)


Absent myoepithelium Absent myoepithelium

Absent myoepithelium

Progesterone receptor (PR)

Progesterone receptor (PR)

Thick fibrous capsule encircles mass

Thick fibrous capsule encircles mass

Surrounding encapsulation and cystic space

Surrounding encapsulation and cystic space

Fibrovascular cores within  epithelial proliferation

Fibrovascular cores within epithelial proliferation


Loss of E-cadherin in the lesion

Loss of E-cadherin in the lesion

Virtual slides

Images hosted on other servers:

Encapsulated papillary carcinoma

Cytology description
  • No formal cytologic criteria exist to distinguish EPC from other benign papillary lesions (J Clin Pathol 2008;61:945)
    • Sensitivity and specificity for specific diagnoses is low
    • If papillary lesion is suspected on FNA, surgical biopsy is necessary for further classification
  • General findings in fine needle aspirates of EPC (Breast J 2006;12:237, J Clin Pathol 2008;61:945)
    • High cellularity, presence of cell balls, presence of slender papillae, mild cytologic atypia
Positive stains
Negative stains
Molecular / cytogenetics description
Videos

Papillary lesions of the breast

Sample pathology report
  • Breast, right, partial mastectomy:
    • Encapsulated papillary carcinoma (see comment)
    • Comment: Histologic sections show a circumscribed papillary tumor surrounded by a thick fibrous capsule. Cytologically, the tumor cells are columnar and cuboidal with low grade nuclear atypia. The lesion lacks myoepithelium throughout the fibrovascular cores and around the periphery. Conventional invasive carcinoma is not seen infiltrating into or beyond the fibrous capsule. In the absence of an invasive carcinomatous component, encapsulated papillary carcinomas are staged as in situ (Tis); however, some believe that they may actually be a very good prognosis subtype of invasive carcinoma due to the lack of myoepithelium.
  • Breast, right, core needle biopsy (when entire lesion is not removed or cannot be visualized):
    • Low grade papillary carcinoma (see comment)
    • Comment: The biopsy contains fragments of an atypical lesion with papillary architecture and low grade monomorphic nuclear atypia. p63 and calponin immunostains are negative for myoepithelium throughout the lesion and around the periphery; however, the periphery of the lesion is not completely visualized in the biopsy. The findings raise the possibility of a low grade encapsulated papillary carcinoma. Papillary ductal carcinoma in situ is also in the differential. A conventional invasive carcinoma is not present in this biopsy. Definitive classification is deferred to the surgical specimen.
Differential diagnosis
Board review style question #1

What is the expected pattern of myoepithelial cell distribution in encapsulated papillary carcinoma of the breast?

  1. Absent both centrally within the lesion and along the periphery
  2. Absent centrally within the lesion but diffusely present along the periphery
  3. Present both centrally within the lesion and along the periphery
  4. Present only focally within the center of the lesion but diffusely present along the periphery
Board review style answer #1
A. Absent both centrally within the lesion and along the periphery. Encapsulated papillary carcinomas characteristically lack myoepithelial cells both within and along the edge of the lesion. The remaining answer choices apply to other papillary lesions of the breast; a benign intraductal papilloma has myoepithelial cells lining the entirety of the proliferation both centrally and peripherally, whereas a papilloma involved by DCIS and papillary DCIS will show focal to complete absence of myoepithelium centrally (corresponding to the regions of atypia) with retention peripherally.

Comment Here

Reference: Encapsulated papillary carcinoma
Board review style question #2
A 72 year old woman undergoes partial mastectomy for a 1.8 cm papillary lesion in the retroareolar tissue of her left breast. A diagnosis of encapsulated papillary carcinoma is made upon finding absent myoepithelium within the papillae and around the periphery. How should this lesion be staged, according to the AJCC TNM classification system?

  1. T0
  2. Tis
  3. T1
  4. T2
Board review style answer #2
B. Tis. Encapsulated papillary carcinoma is staged as an in situ lesion given its similar clinical behavior to ductal carcinoma in situ. If conventional invasive carcinoma is found, infiltrating beyond the fibrous capsule, the lesion should be staged according to the size of the invasive component only; the size of the EPC should not be included for staging.

Comment Here

Reference: Encapsulated papillary carcinoma
Board review style question #3
In which group is encapsulated papillary carcinoma of the breast most commonly seen?

  1. Childhood (≤ 18 years)
  2. Lactating / pregnant
  3. Men
  4. Postmenopausal women
Board review style answer #3
D. Postmenopausal women. Encapsulated papillary carcinoma (EPC) of the breast is an uncommon breast cancer that is classified as in situ, is typically low to intermediate grade and most frequently occurs in elderly, postmenopausal women rather than in younger women. EPCs constitute a slightly higher proportion of breast cancers in male patients as compared to female patients. However, male breast cancer is uncommon and is most frequently invasive ductal carcinoma (comprising about 85% of male breast cancers).

Comment Here

Reference: Encapsulated papillary carcinoma
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