Breast

Invasive breast carcinoma of no special type and variants

NST, rare variants



Last author update: 1 August 2012
Last staff update: 18 June 2024

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PubMed Search: Carcinoma with osteoclastic giant cells, Glycogen rich carcinoma breast , Lipid rich carcinoma breast, Sebaceous carcinoma breast, Signet ring cell breast

Monika Roychowdhury, M.D.
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Cite this page: Roychowdhury M. NST, rare variants. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/breastNSTrare.html. Accessed December 2nd, 2024.
Choriocarcinomatous / pleomorphic patterns (pending)
Clear cell (pending)
Glycogen rich
Definition / general
  • Breast carcinoma in which at least 90% of the neoplastic cells have abundant clear cytoplasm due to glycogen
  • First described in 1981 (Cancer 1981;48:2003)
  • Rare, 1% - 3% of breast carcinomas
  • May be a variant of apocrine carcinoma

Radiology images

Images hosted on other servers:

Mammogram shows circumscribed mass



Prognostic factors

Case reports

Gross images

Images hosted on other servers:

Solid papillary pattern within cystically dilated duct



Microscopic (histologic) description
  • Solid or solid / papillary patterns of large clear cells with distinct cell borders containing glycogen in 90% or more cells
  • Often associated with intraductal component of varied type
  • Often has apocrine features
  • Cells have clear to granular cytoplasm
  • May have scant intracellular mucin (Histopathology 1987;11:857)
  • No cytoplasmic vacuoles

Microscopic (histologic) images

AFIP images

PAS+ dark granules

Clear cells

Sheets of polygonal cells



Images hosted on other servers:

Ample clear cytoplasm

PAS positive

Abundant calcifications

Resembles renal clear cell carcinoma


Intraductal lipid rich carcinoma with component of glycogen rich carcinoma

CK8 / 18+

Polygonal cells



Cytology description
  • Hypercellular with tumor cells in loosely cohesive syncytial groups and some single cells
  • Most tumor cells have abundant, finely granular eosinophilic cytoplasm or foamy to clear cytoplasm with well defined cytoplasmic membranes and moderate / marked nuclear pleomorphism with central round/oval nuclei containing prominent nucleoli (Acta Cytol 2008;52:65)
  • PAS staining may be helpful (J Med Invest 2002;49:193)

Positive stains

Negative stains

Electron microscopy description
  • Non membrane bound glycogen and empty glycogen lakes
  • Tight junctions between tumor cells, immature desmosomes, occasional short microvilli (Am J Surg Pathol 1986;10:553)

Differential diagnosis

Additional references
Lipid rich
Definition / general
  • 90%+ cells have prominent intracytoplasmic neutral lipid

Clinical features
  • 1% - 2% of breast carcinomas
  • Axillary metastases may resemble histiocytes

Prognostic factors
  • Poor prognosis due to frequent (70%) nodal metastases at presentation

Case reports

Gross description
  • Lobulated, variable circumscription, firm
  • 1 to 15 cm

Microscopic (histologic) description
  • Nests, cords and sheets of large polygonal cells with foamy or vacuolated cytoplasm containing lipid
  • May resemble clear cells or lipoblasts
  • Irregular nuclei with coarse chromatin, moderate atypia, prominent nucleoli
  • Other patterns are large pleomorphic cells in alveolar pattern with hobnail appearance, oncocytic or apocrine type change

Microscopic (histologic) images

AFIP images

Polygonal tumor cells



Positive stains

Negative stains

Electron microscopy description

Electron microscopy images

AFIP images

Luminal microvilli, lipid droplets and mitochondria



Differential diagnosis
Oncocytic (pending)
Osteoclast
Definition / general
  • Part of WHO classification
  • Osteoclastic giant cells are present in stroma
  • Presence of giant cells does not alter prognosis

Case reports

Gross description
  • Often brown due to vascular stroma with hemosiderin

Microscopic (histologic) description
  • Giant cells are associated with vascular stroma with extravasated red blood cells and hemosiderin, also chronic inflammatory cells and fibroblasts
  • Giant cells have variable size and variable numbers of nuclei
  • Similar histologic features in nodal metastases and recurrences (Arch Pathol Lab Med 1986;110:636)
  • Carcinoma component may be any type

Microscopic (histologic) images

Images hosted on other servers:

Invasive ductal carcinoma of the breast with osteoclast-like giant cells

Various images



Differentiated well cribriform carcinoma

Osteoclast-like giant cells in close contact to tumor cells



Cytology description

Positive stains

Negative stains

Electron microscopy description
  • Osteoclasts are histiocytes

Additional references
Sebaceous
Definition / general
  • Very rare primary breast carcinoma resembling skin adnexal tumor with sebaceous differentiation, but no evidence of cutaneous derivation (see J Med Case Rep 2008;2:276 for cutaneous tumor of breast)

Clinical features

Case reports

Microscopic (histologic) description
  • Well defined solid sheets or lobules of atypical epithelial cells, including large, pale or clear cells with coarsely vacuolated cytoplasm, containing Oil red O staining lipid and often scalloped nuclei
  • Often focal squamous morules

Microscopic (histologic) images

Images hosted on other servers:

Skin



Positive stains

Negative stains

Electron microscopy description
  • Empty appearing, non membrane bound vacuoles

Differential diagnosis
Signet ring cell
Definition / general

Case reports

Microscopic (histologic) description
  • Mucin fills cytoplasm and displaces nucleus
  • Usually coexists with invasive ductal NOS
  • High nuclear grade; DCIS may be present, but no lobular features (by definition)

Microscopic (histologic) images

Images hosted on other servers:

Breast metastasis to stomach



Cytology description
  • Look for signet ring cells if plasmacytoid cells are identified
  • Favor ductal carcinoma if hypercellular, single signet ring cells, high nuclear grade and tubule formation
  • Favor lobular carcinoma if hypocellular, single signet ring cells and mild / moderate nuclear grade (Cytopathology 2009;20:321)

Differential diagnosis
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