[BACK TO BREAST CANCER INDEX/TOC]
[a molecular/DNA/genomic-based classification]

An interesting WEBSITE with photos of microscopics.

I. Non-Invasive Cancer (CIS):

• ductal CIS adenocarcinoma, click here.
• lobular CIS adenocarcinoma, click here.
• papillary CIS carcinoma, see invasive papillary, below.
• intracystic (non-invasive) carcinoma:
  • papillary: very uncommon⁵...encysted or encapsulated, see papillary below.
  • squamous: extremely rare⁵
• Paget's disease of the nipple (Sir James Paget 1874): only IHC for ck7 need be done to assure Paget's cells and not squamous or melanoma cells; over 50% are associated with an invasive cancer (33% of underlying invasives will be peripheral in breast) and 65% or more of invasives will be grade III & ER & PR negative (some report that lack of finding an underlying invasive is "rare" [12 of the 13 Paget's cases we have processed between 1996 and end of 2006 had an underlying invasive]).

• COMEDO-CIS, large palpable lesion with radiographic "casting microcalcifications" in premenopausal: Dr. Tabar & others have recently defined that these tend to behave like a large, grade III invasive ductal adenocarcinoma (by way of "neoductgenesis") whether pathologist can demonstrate invasion or not [LMC-00-3962; LMC-03-1706/2156; LMC-04-3026; S-04-12003; LMC-05-5239; L07-2942]!¹²
• Invasive LOBULAR adenocarcinoma (ILC): (the big deal with ILC is the nuclear grade...especially pleomorphic (PILC) grade 3 (& 2?), ...the high grade has clearly worse prognosis and is a high risk feature likely warranting more than the least amount of chemo, as marker/molecular profiling is beginning to show:
  • histological types:
    • classical H&E: smallish, monomorphic cells with scant cytoplasm, with low proliferation, tending in Indian files and concentric targetoid infiltrates; usually negative for desmoplastic stromal reaction; cells often have a single intracytoplasmic lumen that is d-PAS and mucicarmine positive.
    • by IHC marker: when lobuloid patterns, E-cadherin negativity gives another line of evidence...cells are negative in lobular & strongly positive in ductal [LMC-02-5160; LMC-05-6986], and variable in mixed IDC/ILC (ductulolobular ca. [L09-5845]). If cytohistology is strongly ILC but is E-cadherin positive, Dr. Page has called a case of ours such as this "invasive carcinoma with lobular features". But, as of 2007, there is identification of a definite small subset of cases that fit "lobular" by many other criteria, yet are E-cadherin positive³⁹. The nuclear grade 1 ILCs are all ER positive.
    • by cell type:
      1. By nuclear characteristics:
      • classic (CILC): monomorphic cells/nuclei and scant cytoplasm...usually B-R grade 1 (Type A) or 2 nuclei (Type B).
      • (aggressive¹⁴) pleomorphic (PILC): tends to present in older PM women with locally advanced disease¹⁸; anaplastic cells (could pass for IDC⁶ but PLCIS & PILC have E-cadherin negativity); usually classic pattern but B-R nuclear grade 2 or 3¹¹; some say any ILC with nuclear grade 2 or 3¹⁷[LMC-07-3360]; PLCIS & PILC have grade 2-3 nuclei with nuclear size variation 2-3x³⁹; PILC is very quick to go to nodes & almost always node positive at time of DX [a PILC not-node-pos. case, L07-1617]; node positive cases 30 times more likely to recur than node positive classic lobular cell type & 29% have some signet ring component¹¹[LMC-07-3209]; probably more aggressive^{9, 11} [LMC-04-3093; LMC-05-2494; LMC-05-2712]. 81% are both ER & HER-2 positive¹⁸[LMC-05-7620].
      2. By cytoplasmic characteristics: lobular is of relatively monomorphic cellularity that is nearly always E-cadherin negative; if some E-cadherin positivity (have not totally lost E-cad expression) but lobular histologiical pattern AND cells with an intracytoplasmic lumen that is AB or mucicarmine positive & radiographically lobular = is lobular³⁹.
      • apocrine variant⁹: probably more aggressive⁹; Fisher noted cases like histiocytoid but with abundant amphophilic cytoplasm (Human Path 15:134, 1984); GCDFP positive; this is a cytoplasmic designation and can apply to CILC or PILC.
      • histiocytoid variant⁹: large individual cells with abundant cytoplasm with occasional large or numerous small mucicarmine pos. vacuoles; this is a cytoplasmic designation and can apply to CILC or PILC.[LMC-02-4776; LMC-03-1764; LMC-05-7620].
      • myoblastoid variant¹⁶: a label for when the histiocytoid change is so extreme that one has to consider the DDX possibility of granular cell tumor.
      • signet ring variant: >20% of cells have signet ring cytology; gross is typical ILC; vacuole is d-Pas and mucicarmine positive¹¹. This is a cytoplasmic designation and can apply to CLC or PLC.
    • by histological growth pattern:
      1. classic (30%): diffuse, single-file, between collagen; biggest diff. dx is vs. a benign lesion⁶.
      2. solid variant (22%): sheets of cells; delicate collagen; biggest diff. dx is with lymphoma⁶;12 year actuarial survival 47%¹¹ [L08-10661; L08-11125, L09-304].
      3. alveolar variant (19%): micro-globular, sharply outlined groups or cell nests of >20 cells⁶, & outlined by fibrous tissue which may contain osteoclast-like giant cells¹⁶.
      4. tubulolobular variant⁹: is really an E-cadherin membrane positive ductal phenotype³⁵ and is to be separated from mixed ductolobular which has a crisply mixed E-cadherin negative lobular component...Fisher noted cases with targetoid & file patterns of extremely compressed tubules with lesser attenuated tubules...photos don't show "Indian files of single cells"; & prognosis between tubular ca. & classical lobular (Human Path 8:679,1977...in lab. conf. room). Higher incidence of multifocality and node mets with this than with pure tubular & 12 year actuarial survival 100%¹¹ [LMC-02-5336]. See below.
      5. mixed/combination (29%): ILC plus some other type⁶...(1) such as lobulo-ductal, ductulo-lobular [LMC-00-5722; S-02-8167; even bilateral tubulolobular, L07-2739] or (2) "collision tumor" formed by two different types arising close to each other & such as E-cadherin may help [LMC-03-7805].
  • grading, click here.
  • prognosis:
    • CILC generally better than IDC-NOS.
    • classical grade 1 is best.
    • variants are worse...especially see PLC, above.
    • ER neg HER-2 pos CILC or PILC may be bad actor⁸.
  • key notes:
    • 14% of CILC have some d-CIS (usually cribriform)⁶.
    •  64% have intra-cytoplasmic vacuoles/lumina⁶, and these lumina are usually mucicarmine & d-PAS positive.
    • 14% have bilateral invasive breast cancer⁶ [LMC-02-7406 contralateral simple mastectomy filled with small invasives].
    • infamous for fairly frequently presenting with visceral metastatic carcinoma [LMC-02-716]; in fact, cases of gastric linitis plastica in women ought always to be checked for the possibility that they are actually metastatic lobular ca. of breast [LMC-02-667]⁸.
    • infamous for reduced detectability by mammography (majority of the 10% mammographic false negative rate is due to lobular ca.)⁸.
    • frequently has a much larger maximum diameter than would appear to be by imaging⁸.
    • becoming a more common breast cancer type among women on HRT for many years⁸.
• Invasive DUCTAL adenocarcinoma:
  • Invasive ductal adenocarcinoma, NOS (IDC)[ordinary IDC]:
    • grading [here]: we use the Elston-Ellis (Nottingham) modification of the Scarf-Bloom-Richardson system.
    • key notes:
      • E-cadherin positivity not invariably an IDC: some have "pleomorphic" cells in an invasive lobular pattern [LMC-05-6389]...both histologically & by lesion imaging it seems ILC, but ca. cells are E-cadherin positive [LMC-02-5160; B09-21] and I've seen Dr. David Page call such a case "invasive breast cancer with lobular features³¹" [B07-111]. By 2009, it appears that there is a small subset of ILC that has not lost E-cadherin expression totally³⁹. Unless cytohistology is compelling toward "lobular"...especially B-R grade 3 pleomorphioc lobular, HER-2 positive cancers that "look lobular" are probably "invasive [ductal] breast cancer with lobular features". Also, see E-cad positive tubulolobular, above.
  • Medullary carcinoma:
    • grading: no actual grade...n/a.
    • key notes:
      1. clinical nodes: often has enlarged nodes which are histologically negative².
      2. the gross and micro MUST be classical: sharply circumscribed mass of SOFT, brain-like tumor; large cells in syncytial (poor cell boundaries) mass; should have a lot of lymphoplasmacytic infiltrate & should expand in size by "pushing margins", not by any infiltration of fat¹³. At least with mastectomy, a 5 times better 5 yr survival than IDC in general⁵.
      3. NOT QUITE: anything short of #2 above is a variant of IDC (IDC with medullary features) which some call "atypical medullary ca." [LMC-04-8136; LMC-05-6779; LMC-07-3299; LMC-07-7292].
      4. IHC markers: (as of 2009, medullary a "triple negative" cancer of MMN or basal-like type)
      • HER-2 usually negative².
      • vimentin more expressed than in IDC, NOS².
      • nuclear p53 pos.².
      • EMA & S100 frequently pos.².
      • <10% are ER &/or PR pos.².
      • among highest growth rate breast cancers² [very high Ki67].
• Tubular carcinoma: a small special grade I IDC with fairly regular, dominantly open lumens (lumens NOT squeezed as in adenosis) fairly evenly involving the lesion in a simple pattern without epithelial complexity and may be seen in fat; epithelial lining basically single-cell layer¹⁹ (IHC neg. for ME cells); has scant atypia, lacking mitoses¹⁶. If epithelium more than 2 cells and any cell nests, best to call it [LMC-06-4732] grade I IDC NOS¹⁹ or IDC with tubular features. Has very infiltrating margins rather than lobulated as in sclerosing adenosis¹⁹. If ER negative, your lab has a fixation or staining problem...these are ALWAYS ER positive tumors!
  • grading: as with IDC.
  • key notes: Lagios found high incidence of  multicentricity, HX of bilateral breast cancer, and positive family HX in tubular cases^{16 (p.1805)}. When pattern is strictly truly a tubular carcinoma, it is "invasive ductal adenocarcinoma, tubular type/variant " [LMC-05-6769].
• tubulolobular variant⁹: Fisher noted cases with targetoid & file patterns of extremely compressed tubules with lesser attenuated tubules...photos don't show "Indian files of single cells"; & prognosis between tubular ca. & classical lobular (Human Path 8:679,1977...in lab. conf. room). Higher incidence of multifocality and node mets with this than with pure tubular & 12 year actuarial survival 100%¹¹ [LMC-02-5336]. Is entirely E-cadherin positive & slightly more aggressive than pure tubular, as 16% have node mets at diagnosis²⁶.
• Acinic cell carcinoma: lobulations and tubules of amphophilic cells with some cases having brightly eosinophilc granules¹⁵.
• Invasive cribriform carcinoma:
  • grading:
  • key notes:
• Tubular mixed carcinoma:
  • grading:
  • key notes:
• Mucinous carcinoma, pure (colloid cancer)[LMC-99-3564; LMC-90-2445; LMC-93-1587; LMC-01-5968; LMC-01-6511; LMC-02-3980; LMC-02-5238; LMC-03-1279; LMC-04-10589]: be sure you are not looking at a "matrix producing" variant of metaplastic carcinoma (see below).
  • grading: could give B-R nuclear grade but usually not graded⁶.
  • key notes:
    • the tumor papillations tend to have smooth peripheries whereas invasive micropapillary ca. has non-smooth, somewhat scalloped peripheries⁷.
    • cellularity: it is worth noting paucicellular histology vs. significantly higher cellularity.
    • pure (90% or more colloid provided the lesser component is NOT poorly differentiated³⁶) colloid ca. never has a spiculated margin by imaging, and it is these lobulated-margin, circumscribed types that behave as colloids should⁶.
    • if not "pure" by above definition, diagnose it as "IDC with mucinous features".
    • about 2% of breast ca.⁵; more prevalent in elderly.
    • tend to use the term "colloid" when the gross cut surface is c/w colloid⁵.
    • other factors being similar, has somewhat less tendency to axillary metastasis, less die, and more live longer⁵.
• Papillary carcinoma, invasive (& non-invasive):
  • note: most of the standard "papillary carcinoma of the breast" are noninvasive, the whole lot of invasive or non-invasives accounting for 2%⁵ or less of breast cancers. Though myoepithelial marker panels may be negative³³, they behave as CIS; & papillary tumors by core biopsy must be excised to rule out any true invasion...see next bullett point.
  • not called "invasive" unless is a "slam dunk", "all-pathologists-would-agree" invasive-component pattern demonstrated.
  • invasive grading: give/assign both an Elston grade & B-R nuclear grade.
  • difficult decision on core biopsies: benign papilloma vs. noninvasive vs. invasive papillary...peripheral stroma tends to have some associated d-CIS with the ca. cases; can have an intracystic/intraductal variant.
  • key notes: this is absolutely different than the quick-to-metastasize "invasive micropapillary carcinoma" (see below) & tends to be in elderly; lobulated & poor in desmoplastic stroma; coarsely papillary variant may be hard to recognize as cancer on core biopsies; a relatively low-grade tumor, very loathe to node metastasize...slow to kill, with 89% actuarial 5yr surv. rate [LMC-02-46; LMC-04-9284].
• Biphasic carcinoma (epithelial plus mesenchymal)²⁸:
• Metaplastic carcinoma: carcinoma with spindled component¹¹ which is keratin positive ⁴, and/or "looks" mesenchymal & tend to use this diagnosis for cases when predominently looks non-epithelial. If strong myepithelial markers, some would call it malignant myoepithelioma.
• "Collision tumor": a carcinoma closely adjacent to a sarcoma & proximate borders infiltrate each other.
• (aggressive) Metaplastic sarcomatoid carcinoma (MCS)²⁴: "carcinosarcoma". Highly aggressive tumor ⁴. Invasive carcinoma component in a highly cellular mitotically active pleomorphic spindled cell tumor that appears to be sarcomatous¹¹ (both components have malignant features) and with that spindled (and maybe some roundish cells) component staining negative for epithelial antigens (or only a rare pos. cell) such as cytokeratins⁴ [LMC-03-4983, L07-538, L07-880]. A "matrix producing variant can look like a mucinous carcinoma at first glance [L08-5832].
1. when very low percentage of tumor is epithelial (no greater than 10%), behaves more like sarcoma with only 5% node positivity & 50% develope distant mets (usually to lungs)²⁵.
2. be careful to not confuse with "collision tumor" phenomenon when a carcinoma is adjacent to a sarcoma.
• Adenocarcinoma with osteoclast-like giant cells (osteoclastic-like cell-containing adenocarcinoma): mostly background IDC but reports with mucinous, tubular, papillary, cribriform, adenoid cystic, and ILC having these giant cell components. Tend well circumscribed (50%) & dark brown to red brown cut surface, often being bloody & with many hemosiderin macrophages, the later sometimes making mammogram seem to have microcalcifications; progosis thought same as NOS per grade & stage [solid & spindled LMC-06-10485]. ²³.
• Mixed carcinoma types (less than 75-90% pure pattern):
  • grading: the system of the most aggressive component.
  • key notes:
  • examples:
    • lobuloductal ca. [LMC-01-6423]; [mixed ductal & lobular with various mets to nodes LMC-04-4497; mixed ? by H&E, but all E-cad positive LMC-05-6389].

• invasive ductal adenocarcinoma, atypical medullary variant (IDC with medullary features)...histology looks like a medullary but has a periphery that can't "shell out" of the surrounding breast [LMC-01-6695]...somewhat infiltrative periphery.
  • BRCA1 positive patients more likely to have these
• circumscribed invasive ductal adenocarcinoma with plasma cell infiltrate of tumor periphery:
  • grading: as with IDC [LMC-04-7129; L09-2841?]
  • key notes:
    • better prognosis than generic IDC⁵
    • best prognosis when plasma cell infiltrate entirely encompasses mass⁵
• Pleomorphic invasive ductal adenocarcinoma²⁷: Is at the extreme end of the spectrum of grade III IDC & 50-100% of tumor is the pleomorphic component & about a third of cases had a spindled component; ER & PR negative.
• Low grade mucoepidermoid carcinoma: not quick to nodes¹¹.
• Low grade adenosquamous carcinoma¹¹:.
• Adenoid cystic carcinoma (ACC):
  • grading: use oral cancer grading of AJC system,
    • grade I: glandulocystic without solid component.
    • grade II: with up to 30% solid component.
    • grade III: over 30% solid component.
  • key notes:
    • about 0.1% of breast cancers [LMC-01-2567].
    • very slow...grudging...to metastasize to nodes⁴.
    • even node neg. (surgery only) sometimes late met., almost always to lung; if node-pos., tend to have lung met.³.
    • if conservative breast surgery, may locally recur, but re-excision curative³.
    • "ACC is one of the least aggressive mammary carcinomas." Goal is complete excision with clear margins ⁴.
    • can occassionally have sebaceous foci (Tavasolli)
• (aggressive¹⁴) invasive micropapillary ca. (IMPC): (described 1993...1991?)
  • identifying it: one senses often-rounded micronodules of small clusters of cancer cells sitting in sometimes-subtle, clear spaces...spaces remindful of shrinkage-artifact clefts (Hartmann's fixative causes an artifact resembling this); remindful of serous papillary ca. of ovary; the aspect of the cell border facing the cleft/space is lumen-like with microvilli, marking with MUC1 (and not CD10) & EMA³⁶, an inside-out lumenal pattern³⁶. Though reports vary, tends ER & PR neg. & HER-2 pos. & E-cadherin positive except on cell side in contact with the surrounding space³⁴. Sometimes appreciate the micropapillary feature best in node mets.
  • 2006 report²² notes that, even when a mixed tumor has <25% IMPC component, very strong proclivity...lymphotropism...to go to nodes (even citing a report that even tumors less than 0.5 cm do so³⁷). Should report it as part of a mixed tumor variant [L07-10488] if any portion is IMPC³⁸.
  • reported in 1994² & and all cases in that report had pos. nodes; relatively pure IMPC is 2.7% of breast cancers.
  • grading: use B-R ductal CIS nuclear grading.
  • both high nuclear grade and lymphocytic host response (especially if follicles present) portend greater likelihood it has already metastasized already to nodes²²; when small & lymphoid rich, the IMPC nature & features hard to discern & DDX clearer in the nodes [L07-737].
  • prior to node mets enlarging, the highly dispersed showering of single cells, doublets & triplets into a positive node may be the tip off to a tiny occult primary within a larger imaging detected micropapillary ductal CIS [L07-1953] or even a primary so tiny that it is not even found in the mastectomy [L07-2749].
  • take great care to be sure that it is not papillation-rich colloid carcinoma [LMC-01-6511], see above. 
  • take reasonable measure to r/o met. pap. serous from ovary (IMPC looks like serous papillary ca. of ovary) [LMC-05-4968]; if widely WT1 nuclear positive and also diffuse cytoplasmic CA125 pos., is likely met. from ovary³⁶.
  • don't write this pattern off as looking papillary due to fixation/retraction artifact (double-check pattern in pos. nodes)[LMC-93-63, L07-6613].
  • ours also often (about 66%) have intramammary intra-lymphatic percolation [LMC-01-8129; LMC-05-2309; LMC-00-4041; L07-4425].
  • key notes: goes very early (high case percentage of axillary node positivity³⁸) to multiple axillary nodes [LMC-01-2980/3688; LMC-01-7388; LMC-01-8129; S-02-6170; LMC-07-4425]. Volume of node mets can be even 10x or more the volume [L07-6613 = the 2 pos. nodes together were 17x vol. of 1cm primary; L07-8718] of the primary, especially when primary is small & enlarged positive nodes can feel benignly soft at surgery [L07-737]. And, we had a case of 2cm d-CIS lumpectomy without invasive cancer but the SLN had met. IMPC & we could not find a primary in the mastectomy [L07-2749].
  • treatment implications: not a good variety for conservative breast surgery & rate of skin & chest wall recurrence (70-90%³⁸) indicates postop radiation therapy, especially if 2cm. or larger & adjuvant chemo if tumor larger than 1.0cm even if node negative³⁶.
• Malignant adenomyoepithelioma: Malignant adenomyoepithelioma of the breast is a rare lesion characterized by malignant proliferation of epithelial and myoepithelial cells that show characteristic histologic and immunohistochemical features.
• Malignant myoepithelioma: a rare lesion characterized by malignant proliferation of myoepithelial cells that show characteristic histologic and immunohistochemical features.
• Neuroendocrine ca. of breast: from carcinoid to "oat cell"... [LMC-95-6240; LMC-98-10195; S-05-40].
• (aggressive¹⁴) Apocrine adenocarcinoma (a type of IDC)
  • grading: Elston, as per IDC [LMC-91-1369; LMC-02-5827; LMC-04-4015; LMC-04-10761].
  • histology: slightly eosinophilic granular (d-PAS + granules) & usually copious cytoplasm, sharp cell borders, some vacuoles, nuclei with prominent nucleoli¹⁴; usually eosinophilic but can have amphophilic cytoplasm [LMC-04-10373; LMC-05-5507].
  • key notes: 
  • <1-2% of breast cancers²; more prevalent in elderly.
  • often has intramammary lymphatic percolation (Breast Ca. Res. & Treat. 12:37-44, 1988)² ; therefore, if this variant is suspected on core biopsies, one might want to be extra cautious as to conservative breast surgery.[LMC-01-3284; LMC-93-2198; LMC-02-3878; cores only showed a little percolation LMC-02-2400; LMC-04-10373; LMC-04-10761; LMC-05-5507]
  • always ER and PR neg.² & androgen receptor & GCDFP15 pos. [LMC-00-7376, LMC-01-3284, LMC-01-5219][LMC-01-6685][LMC-04-3086; LMC-04-10373; LMC-04-10761]; and, if not...
  • better to call it IDC "with apocrine features"[LMC-04-6920] unless is ER/PR weak & androgen receptor pos. and/or has lymphatic percolation [LMC-04-3243].
• (aggressive, both¹⁴) Clear cell carcinoma:
  • glycogen rich variant: PAS pos. lost with diastase [LMC-06-9195; L08-1719].
  • lipid rich (signet-ring like) variant: may have needle mitochondrial crystals & cells vimentin and S-100 positive¹¹.
• Secretory (juvenile) carcinoma: (HERE)
  • grading: NOS...getting the type correct is the main grade statement.
  • key notes:
    • often in children (girls & boys) and young adults; can be at any age³.
    • usually circumscribed mass³.
    • outstandingly good prognosis age 30 & younger.
• Squamous cell carcinoma: may be IDC with a special type of carcinomatous metaplasia & tends to have the same prognosis as NOS IDC, EXCEPT for the very aggressive variant, "acantholytic SCC" (which, at first H&E glance, histology may suggest adenocarcinoma or angiosarcoma²⁹).

• malignant phyllodes tumor: can be as small as 2 cm.; periductal stromal origin and usually at least moderately cellular stroma and at least 2-5 mitoses per 10 hpfs (low grade), hi grade typically exceeding 5 mitoses per 10 hpfs. Low grade has a less than 5% rate of metastasis; while high grade has a high local recurrence rate and 25% metastatic rate, only 5% to axillary nodes.⁷[LMC-03-2377,2552]
• hemangiosarcoma (AS)...generic term for sarcomas of endothelium, whether lymphatic or non-lymphatic:
  • AVL³²: must differentiate from "atypical vascular lesion" (AVL) in the post radiated breast, a clinically small & distinct lesion that does not metastasize but the field is at risk for new AVL lesions. May be a precursor to CPRASB³¹ . Features of AVL³⁰:
    • small lesion (on average) & does not invade subcutis.
    • does not have dilated "blood lakes".
    • does not have papillary endothelial hyperplasia (endothelium is simple).
    • no prominent endothelial nucleoli.
    • negative for mitotic figures.
    • negative for marked endothelial cytologic atypia.
    • perithelial stroma pmicro-knobby, causing endothelial covered stromal projections into vascular lumen.
    • relatively circumscribed (cross-sectional silhouette on slide wedged shaped).
    • maybe there are some nonradiated cases [S09-11282].
  • Angiosarcoma: though formerly called lymphangiosarcoma, the following are thought to actually arise from CD34 positive non-lymphatic channels...hence, "angiosarcoma".
    • CPRASB: "cutaneous postradiation angiosarcoma of breast" (CPRASB): has been seen with conservative breast surgery followed by radiation [S-05-13996]; CPRASB mets to other breast in 3 of 27 cases²⁰. Low grade CPRASB can have some features of AVL but "grade has little to do with prognosis. CPRASB is,
    • STAS: different from the chronic-lympedema-associated AS...no matter the reason for lymphedema...(lymphangiosarcoma... postmastectomy angiosarcoma) of Stewart-Treves (STAS) reported in 1948.
• Fibrosarcoma and malignant fibrous histiocytoma: [LMC-99-694 MFH; LMC-04-2885 MFH]; be sure is K903 & LMW-keratin negative so that sarcomatoid carcinoma is ruled out).
• Liposarcoma:
• Rhabdomyosarcoma:
• Osteosarcoma:
• Leimyosarcoma:
• Chondrosarcoma: be sure not a metaplastic ca.
• Other rare sarcomas:
• Malignant lymphoma:
  • primary
  • recurrent [LMC-01-3971]
• Plasmacytoma:
• Leukemia: [S-89-349]

1. Systemic Pathology 3rd ed., vol. 13, The Breast,  C. W. Elston and I. O. Ellis 1998
2. Rosen's Breast Pathology, text, 1st Ed. 1997.
3. AFIP fascicle
4. Tavasolli FA, Pathology of the Breast, p. 1-669, 1992.
5. AFIP fascicle #2, McDivitt & Stewart, 1968
6. Interdisciplinary Conference 2 vol. manuals, 9/2000 Palm Springs, Calif., Lazlo Tabar seminar
7. Rosen's core biopsy atlas, 1999 [EBS]
8. local expert comments, weekly breast ca. conf. @ LMC
9. The Difficult Diagnosis in S. P., Noel Widener, 1996
10. Prognostication of Invasive Ductal Breast Cancer by Quantitation of E-cadherin Immunostaining: the methodology and clinical relevance, Elzgheid A, et. al., Histopathology 41(2):127-133, August 2002 (EBS's office)
11. Carter, Darryl, Interpretation of Breast Biopsies, 4th Edition, 2003.
12. Tabar L & Cardenosa G, "SCRS First Annual Breast Symposium", 19 &20 January 2003.
13. Haber MH, et. al., Differential Diagnosis in Surgical Pathology, 2002. [EBS's office]
14. Varga Z, "Preferential...in aggressive histological subtypes...", Histopathology 44(4):332-338, April 2004.
15. Peintinger F, et. al., "Acinic cell...", Histopathology 45(6):593-602, December 2004.(EBS's office)
16. Rosai J, Rosai AND Ackerman's Surgical Pathology, 9th Ed., p. 2389-2394, 2004.
17. Weidner N, et. al., Pleomorphic variant of invasive lobular carcinoma of the breast, Human Pathology, 23(10):1167-71, Oct. 1992.
18. Middleton LP, AJSP, Dec 2000, 24(12):1650-6.
19. Silverberg  SG, Atlas of Breast Pathology, 206 pages, 2002.
20. Weiss, SW, et. al., "Cutaneous Angiosarc...", AJSP 28(6):781-788, 6/2004.
21. Gown AM, personal communication relative to: Cytokeratin 8 Immunostaini9ng and E-Cadherin Expression Distinguish Lobular From Ductal Breast Carcinoma, AJCP 114:190-196, 2000.
22. Guo X, et. al., "Invasive Micropapillary Carcinoma of the Breast...Association of Pathologic Features with Lymph Node Metastasis ", AJCP 126(5):740-746, November 2006 [on MEDSCAPE website].
23. on-line, "Best cases from the AFIP: Inv. Ductal Ca. with Osteoclast-like Giant Cells" (1/3/06 web search...http://radiographics.rsnajnls.org/cgi/content/full/22/3/691).
24. Hennessy BT, et. al., @ MD Anderson Ca. Ctr., Annals of Oncology 17(4):605-613, 9 Feb 2006.
25. Davis WG, et. al., @ MD Anderson Ca. Ctr., Am. J. Surg. Path. 29(11):1456-63, Nov. 2005.
26. Esposito NN, et. al., U. of Pittsburg, Modern Pathology 20(1):130-138, Jan. 2007.
27. Silver SA & Tavassoli FA, from the AFIP, Histopath. 36(6):505-14 June 2000.
28. Rosai J, Rosai and Ackerman's Surgical Pathology, 2 vol. text 2977 pages, 2004.
29. Eusebi V, et. al., "Acantholytic Variant of Squamous-cell Carcinoma of the Breast", Am. J. Surg. Path. 10(12):855-61 Dec. 1986.
30. Rosen PP, Rosen's Breast Pathology, Second Ed., 2001, 1004 pages.
31. Expert unpublished comments at seminars, by case consultation, by e-mail, etc.
32. Brenn T & Fletcher CDM, "Radiation Associated Cutaneous Atypical Vascular Lesions and Angiosarcoma...Clinicopathologic Analysis of 42 Cases", AJSP 29(8):983-996, August 2005.
33. Gown AM, et. al., Papillary Carcinomas of the Breast: a Reevaluation Using a Panel..., Am. J. Surg. Path. 30:1002-1007, 2006.
34. Pettinato G, et. al., "Invasive Micropapillary Carcinoma of the Breats", AJCP 121(6):857-866, 2004 (U. of Minn & Naples, Italy).
35. Esposito NN, et. al., "The Ductal Phenotypic Expression of the E-cadherin/catenin Complex in Tubulolobular Carcinoma...", Modern Pathology 20:130-138, 2007.
36. Rosen's Breast Pathology, text, 3rd Ed. 2009.
37. Walsh m., "Invasive micropapillary carcinoma of the breast: Eighty cases of an underrecognized entity", Human Pathology, 32(6): 583-589, 2001.
38. Stanford U.'s S. P. criteria website, BREAST.
39. Schnitt SJ, breast cancer topics, Gordon R. Hennigar Memorial Lecture, S. C. Society of Pathologists fall meeting, Grove Park Inn, Asheville, N. C. 12 Sept. 2009.

(posted Nov. 2000; latest addition 17 January 2010)