Breast malignant, males, children
Carcinoma subtypes
Metaplastic carcinoma - matrix producing subtype

Author: Monika Roychowdhury, M.D. (see Authors page)

Revised: 28 October 2016, last major update September 2012

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Matrix producing subtype of metaplastic carcinoma

Cite this page: Metaplastic carcinoma - matrix producing subtype. website. Accessed October 24th, 2018.
Definition / general
  • Invasive breast carcinoma with direct transition of carcinoma to cartilaginous or osseous matrix, without an intervening spindle cell component (Hum Pathol 1989;20:628)
  • Rare
  • 44% are age 50 years or less
Clinical features
Case reports
Gross description
  • 31% are 2 cm or smaller, 50% are between 2 - 5 cm and 19% are 5 cm or larger
Gross images

Images hosted on PathOut server:

Cartilaginous tumor with arrows at tumor margin

Circumscribed tumor with bulging mucoid surfaces

Microscopic (histologic) description
  • Invasive breast carcinoma with direct transition of carcinoma to cartilaginous or osseous matrix, without an intervening spindle cell component
  • Nests, sheets and cords of tumor cells with cellular atypia, plus scattered cancer cells within myxoid or myxohyalinous stroma
  • Almost always chondroid matrix, rarely osseous matrix
  • Matrix volume varies from 10% of less (44% of cases) to 40% or higher (28%)
  • Usually (94%) high grade matrix tumor cells with peripheral lymphocytic infiltration
  • Expansile growth with well-circumscribed margins, accompanied by basophilic and myxoid intercellular matrix
  • Gradual transition from cellular to acellular areas, with gradual loss of tumor cell adhesion
  • Central necrosis (59%), angiolymphatic invasion (25%) and axillary nodal metastases (22%)
Microscopic (histologic) images

Images hosted on PathOut server:
AFIP images

Matrix producing

appearance of
matrix metaplasia

metaplasia in
anaplastic portion
of a carcinoma

Zone of osteoid
separates two
areas of poorly

Junction between
poorly differentiated
carcinoma and
lobulated areas of

Images hosted on other servers:

Various images

Central myxoedematous area with necrosis


AE1 / AE3+

Cytology description
  • Markedly atypical spindle cells with mitotic figures, also atypical chondrocytes (Diagn Cytopathol 2005;33:205)
  • Background is necrotic debris and myxoid substance displaying metachromasia
Cytology images

Images hosted on other servers:

Fig 1: FNA shows metachromatic chondromyxoid extracellular material with chondrocyte-like cells
Fig 2: poorly differentiated tumor with sheets of small undifferentiated cells, mitotic figures and necrosis
Fig 3: chondromyxoid matrix with pleomorphic cells within lacunae
Fig 4: cells in chondromyxoid matrix are S100+

Positive stains
Negative stains
Differential diagnosis
  • Central acellular carcinoma: margins are relatively sharp with infiltrative growth accompanied by eosinophilic intercellular matrix; abrupt transition from peripheral cellular to central acellular zones without alteration of tumor cell adhesion (Pathol Int 2009;59:390)