Invasive lobular carcinoma: Difference between revisions
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{{Breast cancer staging}} | {{Breast cancer staging}} | ||
{{Evaluation of tumors}} | {{Evaluation of tumors}} | ||
{{Grading of breast cancer| | === Grading === | ||
The '''Nottingham system'''<ref>{{cite journal |last1= Elston |first1= CW |last2= Ellis |first2= IO |title= Pathologic prognostic factors in breast cancer. I. The value of histological grades in breast cancer. Experience from a large study with long-term follow-up |journal= Histopathology |year= 1991 |volume= 19 |issue= 5 |pages= 403–10 |pmid= 1757079 |doi=10.1111/j.1365-2559.1991.tb00229.x}} {{cite journal |title= Republished |year= 2002 |doi= 10.1046/j.1365-2559.2002.14892.x | volume=41 |journal=Histopathology |pages=154–161}}</ref> is recommended for breast cancer grading.<ref>{{cite web|title=What is the Nottingham combined histologic grade (modified Scarff-Bloom-Richardson grade) system for breast tumors?|url=https://www.medscape.com/answers/1668113-181367/what-is-the-nottingham-combined-histologic-grade-modified-scarff-bloom-richardson-grade-system-for-breast-tumors|author=Oudai Hassan|website=Medscape}} Updated: Mar 20, 2019</ref> The Nottingham system is also called the Bloom–Richardson–Elston system ('''BRE''')<ref>{{cite journal | last1= Al-Kuraya| first1= Khawla| last2=Schraml | first2=Peter |display-authors=et al | title= Prognostic relevance of gene amplifications and coamplifications in breast cancer | journal=Cancer Research| volume=64 | issue=23 | year=2004| pages= 8534–8540}}</ref>, or the Elston-Ellis modification<ref>Elston CW, Ellis IO. Pathologic prognostic factors in breast cancer. I. The value of histological grades in breast cancer. Experience from a large study with long-term follow-up. Histopathology 1991, 19:403-410.</ref> of the Scarff-Bloom-Richardson grading system.<ref name="BloomRichardson1957">{{Cite journal | last1 = Bloom | first1 = H.J. | last2 = Richardson | first2 = W.W. | title = Histological grading and prognosis in breast cancer; A study of 1409 cases of which 359 have been followed for 15 years | journal = British Journal of Cancer | volume = 11 | issue = 3 | pages = 359–77 | year = 1957 | pmid = 13499785 | pmc = 2073885 | doi=10.1038/bjc.1957.43}}</ref><ref name="Genestie1998">{{Cite journal | last1 = Genestie | first1 = C. | last2 = Zafrani | first2 = B. | last3 = Asselain | first3 = B. | last4 = Fourquet | first4 = A. | last5 = Rozan | first5 = S. | last6 = Validire | first6 = P. | last7 = Vincent-Salomon | first7 = A. | last8 = Sastre-Garau | first8 = X. | title = Comparison of the prognostic value of Scarff-Bloom-Richardson and Nottingham histological grades in a series of 825 cases of breast cancer: Major importance of the mitotic count as a component of both grading systems | journal = Anticancer Research | volume = 18 | issue = 1B | pages = 571–6 | year = 1998 | pmid = 9568179}}</ref> It grades breast carcinomas by adding up scores for tubule formation, nuclear pleomorphism, and mitotic count, each of which is given 1 to 3 points. The scores for each of these three criteria are then added together to give an overall final score and corresponding grade as follows. | |||
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==== Tubule formation ==== | |||
{{#ifeq: {{{lobular}}} |yes|By definition, classic invasive lobular carcinoma is scored as 3.<ref>{{cite web|url=http://surgpathcriteria.stanford.edu/breast/inflobcabr/grading.html|title=Infiltrating Lobular Carcinoma of the Breast|website=Stanford Medicine|accessdate=2021-01-06}}</ref>|[[File:Tubule formation score in the Nottingham system.jpg|thumb|500px|Tubule formation score in the Nottingham system]] | |||
The overall appearance of the tumor is considered.<ref name="PujaniSharma2014">{{cite journal|last1=Pujani|first1=Mukta|last2=Sharma|first2=KiranLata|last3=Srivastava|first3=AN|last4=Singh|first4=US|last5=Bansal|first5=Cherry|title=Grading systems in the cytological diagnosis of breast cancer: A review|journal=Journal of Cancer Research and Therapeutics|volume=10|issue=4|year=2014|pages=839|issn=0973-1482|doi=10.4103/0973-1482.140979}}</ref> | |||
* 1 point: tubular formation in more than 75% of the tumor (it may in addition be termed "majority of tumor") | |||
* 2 points: tubular formation in 10 to 75% of the tumor ("moderate") | |||
* 3 points: tubular formation in less than 10% of the tumor ("little or none")}} | |||
==== Nuclear pleomorphism ==== | |||
Such as nuclei being larger, darker, or irregular/pleomorphic. | |||
Note: The cancer areas having cells with the greatest atypia should be evaluated. | |||
* 1 point: nuclei with minimal or mild variation in size and shape | |||
* 2 points: nuclei with moderate variation in size and shape | |||
* 3 points: nuclei with marked variation in size and shape | |||
<gallery mode=packed heights=200> | |||
File:Micrograph of ductal carcinoma with mild nuclear pleomorphism.jpg|Ductal carcinoma with mild nuclear pleomorphism. | |||
File:Micrograph of invasive ductal carcinoma of tubular type with moderate nuclear pleomorphism (crop).jpg|Invasive ductal carcinoma with moderate nuclear pleomorphism. | |||
File:Micrograph of invasive ductal carcinoma with marked nuclear pleomorphism.jpg|thumb|Invasive ductal carcinoma with marked nuclear pleomorphism. | |||
</gallery> | |||
==== Mitotic count ==== | |||
[[File:Mitosis appearances in breast cancer.jpg|thumb|Mitosis appearances in breast cancer]] | |||
Mitotic figures are counted only at the periphery of the tumor, and counting should begin in the most mitotically active areas. | |||
* 1 point: Between 0-5 and 0-11 mitotic counts per 10 high-power fields (HPFs), depending on type of microscope used.<ref name=HPF group=notes>Mitotic count: | |||
* 1 point: 0-9 mitotic counts per 10 fields under X25 objective using the Leitz Ortholux microscope, 0-5 mitotic counts per 10 fields under X40 objective using the Nikon Labophot microscope, or 0-11 mitotic counts per 10 fields under X40 objective using the Leitz Daiplan microscope | |||
* 2 points: 10-19 mitotic counts per 10 fields under X25 objective using the Leitz Ortholux microscope, 6-10 mitotic counts per 10 fields under X40 objective using the Nikon Labophot microscope, or 12-22 mitotic counts per 10 fields under X40 objective using the Leitz Daiplan microscope | |||
* 3 points: Over 19 mitotic counts per 10 fields under X25 objective using the Leitz Ortholux microscope, over 10 mitotic counts per 10 fields under X40 objective using the Nikon Labophot microscope, or over 22 mitotic counts per 10 fields under X40 objective using the Leitz Daiplan microscope</ref> | |||
* 2 points: Between 6-10 and 12-22 mitotic counts per 10 HPFs.<ref name=HPF group=notes/> | |||
* 3 points: Over 10 to 22 mitotic counts per 10 HPFs.<ref name=HPF group=notes/> | |||
==== Overall grade ==== | |||
The scores for each of these three criteria are added together to give a final overall score and a corresponding grade as follows: | |||
* 3-5 '''Grade 1''' tumor ('''well-differentiated'''). Best prognosis. | |||
* 6-7 '''Grade 2''' tumor ('''moderately differentiated'''). Medium prognosis. | |||
* 8-9 '''Grade 3''' tumor ('''poorly differentiated'''). Worst prognosis. | |||
{{Immunohistochemistry evaluation of breast cancer}} | {{Immunohistochemistry evaluation of breast cancer}} | ||
*'''Estrogen and progesterone''' receptor positivity | *'''Estrogen and progesterone''' receptor positivity | ||
Revision as of 14:53, 13 September 2021
Author:
Mikael Häggström [note 1]
Invasive lobular carcinoma (ILC):
Gross examination
As per:
or mastectomy.
Microscopic evaluation
Characteristics
The "classic" pattern is round or ovoid cells with little cytoplasm in a single-file infiltrating pattern, sometimes concentrically giving a targetoid pattern.
Subtyping
The histologic patterns mainly include:[1][2][3]
| Type | Prevalence | Description | Image |
|---|---|---|---|
| Classical | 40% | Round or ovoid cells with little cytoplasm in a single-file infiltrating pattern, sometimes concentrically giving a targetoid pattern | File:Classic Invasive Lobular Carcinoma of the Breast (6813147194).jpg |
| Mixed | 40% | No dominant pattern | |
| Solid | 10% | Sheets of classical-appearing cells with little intervening stroma. | |
| Alveolar | 5% | Aggregates of classical-appearing cells | |
| Tubulolobular | 5% | Cells form microtubules in >90% of tumor (smaller than in tubular carcinoma) | |
| Pleomorphic | Classical-appearing but with pleomorphic cells. It may include signet-ring cells, or plasmacytoid cells (pictured) which have abundant cytoplasm and eccentric nuclei. |
Differential diagnosis
- In invasive lobular carcinoma, malignant cells have penetrated the basement membrane, in contrast to lobular carcinoma in situ.
- Invasive ductal carcinoma typically has duct-forming tumor cells rather than single files of tumor cells. In uncertain cases, stain for E-cadherin and p120:
-
Invasive ductal carcinoma, with occasional entrapped normal ducts (arrow).
-
E-cadherin is negative in invasive lobular carcinoma (shown), but has membranous staining in invasive ductal carcinoma
-
p120 has cytoplasmic staining in invasive lobular carcinoma (shown), but has membranous staining in invasive ductal carcinoma
Staging
Stage by the TNM system as follows in sections below.
Also, look for any angiolymphatic invasion. If present, check whether it reaches outside the tumor, and if so, how far.[4] Give greatest dimension (,or 3 dimensions, generally by adding up the estimated thicknesses of involved slices)).[4]
Primary Tumor (T)Tumor – Depends on the tumor at the primary site of origin, as follows:[5]
Regional Lymph Nodes (N)The lymph node values depend on the number, size and location of breast cancer cell deposits in various regional lymph nodes, such as the armpit (axillary lymph nodes), the collar area (supraclavicular lymph nodes), and inside the chest (internal mammary lymph nodes.)[7][8] Each stage is as follows:[5]
Distant Metastases (M)
Overall stageA combination of T, N and M, as follows:[5]
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- Further information: Evaluation of tumors
Grading
The Nottingham system[9] is recommended for breast cancer grading.[10] The Nottingham system is also called the Bloom–Richardson–Elston system (BRE)[11], or the Elston-Ellis modification[12] of the Scarff-Bloom-Richardson grading system.[13][14] It grades breast carcinomas by adding up scores for tubule formation, nuclear pleomorphism, and mitotic count, each of which is given 1 to 3 points. The scores for each of these three criteria are then added together to give an overall final score and corresponding grade as follows.
Tubule formationThe overall appearance of the tumor is considered.[15]
Nuclear pleomorphismSuch as nuclei being larger, darker, or irregular/pleomorphic. Note: The cancer areas having cells with the greatest atypia should be evaluated.
Mitotic countMitotic figures are counted only at the periphery of the tumor, and counting should begin in the most mitotically active areas.
Overall gradeThe scores for each of these three criteria are added together to give a final overall score and a corresponding grade as follows:
ImmunohistochemistryLook at local protocols for what immunohistochemistry tests and other biomarker test need to be tested for each case of invasive breast cancer, or what needs to be retested for subsequent excisions at the primary site or at metastatic sites.[note 2] Ki-67 index- Not be located in stroma. - Be at least half within the field of view. - Be large enough. Otherwise, even weakly positive nuclei count as positive. Ki-67 index is mainly relevant in those with stage T1-T2, N0-N1, to determine if chemotherapy is needed (if Ki67 is >30% rather than <5%).[16] Ki-67 index is most feasibly quantified by a hot spot method,[note 3] Hot spots are areas in which Ki-67 staining is particularly higher relative to the adjacent tumor areas.[17] Usually, the invasive edge of a tumor is a hot spot.[17] When a tumor had several hot spots, the “hottest” spot is selected.[17] Aim to count at least 500 cells in each case, but this is not always possible in cases with low tumor cell density and small tumor size.[17] Also aim to include at least three high-power (×40 objective) fields. Count a nucleus as “positive” if there is any definite brown staining in the nucleus of an invasive breast cancer cell, above the surrounding background in the cytoplasm and extracellular matrix.[18] If a comparisons must be made between core biopsies and sections from an excision, evaluation of the latter should be across the whole tumor.[16] Only nuclear staining counts. Staining intensity of a positive nucleus is not relevant.[16] HER2HER2 can initially be evaluated by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH). If IHC is performed first and is borderline/equivocal, then FISH is recommended.[19] If FISH is performed first and indicates that further workup is required, then IHC may be the performed as per established algorithms.[note 4] HER2 immunohistochemistryLook at different parts of the tumor, and evaluate the area(s) with most staining. When negative of faint staining is seen, evaluate at high magnification.
Micrographs showing each score:[23]
HER2 FISHHER2 FISH usually uses chromosome enumeration probe 17 (CEP17) to count the amount of chromosomes. Hence, the HER2/CEP17 ratio reflects any amplification of HER2 as compared to the number of chromosomes. To prepare a slide for HER2 testing, you may need to choose a paraffin-embedded and mark the resulting slide so that you or whoever interprets it knows where to look for the target tumor cells. When there are multiple blocks of the same case, choose the the one with most tumor. (If a block has undergone sectioning for immunohistochemistry (such as ER, PR and/or Ki67) make sure that you have a new H&E slide at a level next to the one to be used for FISH, so that they will correlate better.) In cases of both invasive and in situ carcinoma in the same specimen, mark all invasive carcinoma (also for crushed tissue or with other artifacts) but not the in situ carcinoma. Also mark a small area of normal tissue as an internal control. If possible, it should be a bit away from the tumor, even if only consisting of fatty tissue. To interpret a HER2 FISH study, first perform a quality control check of the slide as per manufacturer and/or local protocol (generally including checking for proper signals from a control specimen). In cases of both invasive and in situ carcinoma in the same specimen, only score the invasive cells. The signals of 20 cells are usually counted. Also focus up and down on each nucleus to find all signals therein.
If a cytotechnologist has already performed a count, you do not have to recount, but make sure the count is reasonable regarding what you see. In any case, also look around for any obvious tumor heterogeneity in HER2 signals. If the HER2/CEP17 ratio is borderline (1.8-2.2), count an additional 20 nuclei and recalculate a ratio for the total of 40 nuclei.
If the initial HER2 result is negative for a needle biopsy of a primary breast cancer, a new HER2 test may be performed on the subsequent breast excision.[note 4]
ReportBreast excision
Example:
Needle or core biopsy
For cancers, generally include a synoptic report, such as per College of American Pathologists (CAP) protocols at cap.org/protocols-and-guidelines.
Notes
Main pageReferences
Image sources
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