Prostate adenocarcinoma: Difference between revisions
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In case of only less specific findings, consider an '''atypical small acinar proliferation''' ('''ASAP'''), which is a lesion that is probably carcinoma but either lacks definitive diagnostic features, or is too small to be certain.<ref name=stanford-asap>{{cite web|url=http://surgpathcriteria.stanford.edu/prostate/adenocarcinoma/atypical-small-acinar-proliferation-asap.html|title=Prostatic Adenocarcinoma - Atypical Small Acinar Proliferation (ASAP)|website=Stanford Medical School|accessdate=2020-09-14}}</ref> It should not be used for benign lesions that are just unusual looking.<ref name=stanford-asap/> | In case of only less specific findings, consider an '''atypical small acinar proliferation''' ('''ASAP'''), which is a lesion that is probably carcinoma but either lacks definitive diagnostic features, or is too small to be certain.<ref name=stanford-asap>{{cite web|url=http://surgpathcriteria.stanford.edu/prostate/adenocarcinoma/atypical-small-acinar-proliferation-asap.html|title=Prostatic Adenocarcinoma - Atypical Small Acinar Proliferation (ASAP)|website=Stanford Medical School|accessdate=2020-09-14}}</ref> It should not be used for benign lesions that are just unusual looking.<ref name=stanford-asap/> | ||
In uncertain cases, a diagnosis of malignancy can be excluded by immunohistochemical detection of basal cells (or confirmed by absence thereof),<ref name="CruzSantana2016"/> such as using the '''PIN-4''' cocktail of stains | In uncertain cases, a diagnosis of malignancy can be excluded by immunohistochemical detection of basal cells (or confirmed by absence thereof),<ref name="CruzSantana2016"/> such as using the '''PIN-4''' cocktail of stains (which consists of P504S, p63 and high-molecular-weight keratins (HMWK) such as CK5 and CK14).</ref> | ||
[[File:PIN-4 staining of benign prostate gland and adenocarcinoma.jpg|left|220px]] | [[File:PIN-4 staining of benign prostate gland and adenocarcinoma.jpg|left|220px]] | ||
Picture at left compares a PIN-4 immunohistochemistry of benign gland (left) and adenocarcinoma (right) using PIN-4. The adenocarcinoma lacks the basal epithelial cells (stained dark brown by p63 | Picture at left compares a PIN-4 immunohistochemistry of benign gland (left) and adenocarcinoma (right) using PIN-4. The adenocarcinoma lacks the basal epithelial cells (stained dark brown by p63 and HMWK). Also, in PIN-4 stained samples, adenocarcinoma cells generally display red cytoplasms (stained by AMACR, also known as P504S), while benign glands do not. | ||
<br clear=all> | <br clear=all> | ||
===Subdiagnoses=== | ===Subdiagnoses=== | ||
Revision as of 19:47, 7 October 2020
Authors:
Mikael Häggström; Authors of integrated Creative Commons article[1] [note 1]
Comprehensiveness
On this resource, the following formatting is used for comprehensiveness:
- Minimal depth
- (Moderate depth)
- ((Comprehensive))
Gross processing
As prostatectomy or biopsy.
Microscopic evaluation
Screening method
- Before microscopy, look at each microscopy slide by eye, to plan the microscopy screening so as to not miss peripheral fragments.
- Screen at low power, and switch to high power when encountering glandular structures that can not otherwise be cleared. Look in particular for those surrounding nerves.
- At least if no cancer is seen, also look for inflammation.[notes 1]
Characteristics of adenocarcinoma
- Relatively common and highly specific findings of prostatic adenocarcinoma
- [1]
-
Multiple nucleoli (Pictured in an acinar adenocarcinoma, the most common subdiagnosis of prostate adenocarcinoma)
-
Eccentric nucleoli[1] (pictured example has double and eccentric nucleoli).
- Specific but relatively rare signs of adenocarcinoma
- [notes 2]
On biopsies, look in particular near the tips for perineural invasion, as it is most likely seen by the capsule. Glands adjacent to and indenting nerves is not sufficient as a diagnostic criterion by itself. Glands partially surrounding a nerve is an indication of carcinoma.[2]
- Collagenous micronodules for acinar adenocarcinoma[1]
- Angiolymphatic invasion[1]
- Extraprostatic extension,[1] which in biopsies can be diagnosed when tumor cells are located in fatty tissue.
- Less specific findings
-
Mitoses: also seen in for example high-grade prostatic intraepithelial neoplasia (HGPIN) and prostate inflammation.[1] Picture shows adenocarcinoma with two mitoses in reactive epithelium.
-
Intraluminal blue mucin[1] (pictured in acinar adenocarcinoma)
-
Intraluminal atypical eosinophilic secretions.[1]
-
Intraluminal crystalloids.[3]
-
Uneven distribution and infiltrative pattern of glands
-
Glomerulations, for acinar adenocarcinoma, consisting of epithelial proliferations into one or more gland lumina, typically a cribriform tuft with a single attachment to the gland wall.[2]
- Prominent nucleoli[1]
- Nuclear enlargement
Precancerous lesions
In case of only less specific findings, consider a Prostatic intraepithelial neoplasia (PIN) or an atypical small acinar proliferation (ASAP).
A PIN is where acini are architecturally benign, but individual cells display atypia. In high-grade PIN (HGPIN), the changes are similar to those of prostate cancer, whereas in low-grade (LGPIN) the changes are milder. Most pathologists do not report the presence of LGPIN.[5]
An ASAP is a lesion that is probably carcinoma but either lacks definitive diagnostic features, or is too small to be certain (see image below).[6] It should not be used for benign lesions that are just unusual looking.[6] In uncertain cases, a diagnosis of adenocarcinoma can be excluded by immunohistochemical detection of basal cells (or confirmed by absence thereof),[1] such as using the PIN-4 cocktail of stains (which consists of P504S, p63 and high-molecular-weight keratins (HMWK) such as CK5 and CK14).
-
Small acinar cell proliferation, with acinar cells with large nuclei, prominent nucleoli (arrows marking two of them) and no certain basal cell lining.
-
PIN-4 staining of benign prostate gland and adenocarcinoma
Picture above compares a PIN-4 immunohistochemistry of benign gland (left) and adenocarcinoma (right) using PIN-4. The adenocarcinoma lacks the basal epithelial cells (stained dark brown by p63 and HMWK). Also, in PIN-4 stained samples, adenocarcinoma cells generally display red cytoplasms (stained by AMACR, also known as P504S), while benign glands do not.
-
Atrophy is a differential diagnosis to prostate cancer. This example shows gradually increasing simple atrophy from left to right, H&E stain. Crowding and angulation may mimic that of adenocarcinoma, but there is nuclear basophilia rather than atypia, and occasional basal cells can still be seen.
-
Also, seminal vesicle glands may mimic prostatic adenocarcinoma by crowded glands with enlarged hyperchromatic and irregular nuclei, but will have inconspicuous nucleoli and coarse refractile golden brown lipofuscin granules.[7]
Characteristics
- Relatively common and highly specific
- [1]
-
multiple nucleoli (Pictured in an acinar adenocarcinoma, the most common subdiagnosis of prostate adenocarcinoma)
-
Eccentric nucleoli[1] (pictured example has double and eccentric nucleoli).
- Specific but relatively rare signs of adenocarcinoma
- [notes 3]
- Collagenous micronodules for acinar adenocarcinoma[1]
- Angiolymphatic invasion[1]
- Extraprostatic extension,[1] which in biopsies can be diagnoses when tumor cells are located in fatty tissue.
- Less specific findings
-
Mitoses: also seen in for example high-grade prostatic intraepithelial neoplasia (HGPIN) and prostate inflammation.[1] Picture shows adenocarcinoma with two mitoses in reactive epithelium.
-
Intraluminal blue mucin[1] (pictured in acinar adenocarcinoma)
-
Intraluminal atypical eosinophilic secretions.[1]
-
Uneven distribution and infiltrative pattern of glands
- Prominent nucleoli[1]
- Nuclear enlargement
In case of only less specific findings, consider an atypical small acinar proliferation (ASAP), which is a lesion that is probably carcinoma but either lacks definitive diagnostic features, or is too small to be certain.[6] It should not be used for benign lesions that are just unusual looking.[6]
In uncertain cases, a diagnosis of malignancy can be excluded by immunohistochemical detection of basal cells (or confirmed by absence thereof),[1] such as using the PIN-4 cocktail of stains (which consists of P504S, p63 and high-molecular-weight keratins (HMWK) such as CK5 and CK14).</ref>
Picture at left compares a PIN-4 immunohistochemistry of benign gland (left) and adenocarcinoma (right) using PIN-4. The adenocarcinoma lacks the basal epithelial cells (stained dark brown by p63 and HMWK). Also, in PIN-4 stained samples, adenocarcinoma cells generally display red cytoplasms (stained by AMACR, also known as P504S), while benign glands do not.
Subdiagnoses
The histopathologic subdiagnosis of prostate cancer has implications for the possibility and methodology of any subsequent Gleason scoring.[9] The most common histopathological subdiagnosis of prostate cancer is acinar adenocarcinoma, constituting 93% of prostate cancers.[10] The most common form of acinar adenocarcinoma, in turn, is "adenocarcinoma, not otherwise specified", also termed conventional, or usual acinar.[11]
| Subdiagnosis | Relative incidence | Image | Microscopic characteristics | Immunohistochemistry | Gleason scoring | ||
|---|---|---|---|---|---|---|---|
| Core biopsy |
Radical prostatectomy | ||||||
| Acinar adenocarcinoma - 93%[10] |
Adenocarcinoma (not otherwise specified/ conventional/ usual acinar)[11] |
77%[notes 6] | 54%[notes 6] | File:Micrograph of prostate cancer with Gleason score 8 (4+4) with glomeruloid glands.jpg | Tumorous glands: | As usual | |
| Foamy gland carcinoma | 17%[12][notes 5] | 13–23%[12][notes 5] | Based on architecture, discounting foamy cytoplasms[9] | ||||
| Atrophic carcinoma | 2%[12][notes 7] | 16%[12][notes 7] | Tumorous glands: | As usual[9] | |||
| Pseudohyperplastic carcinoma | 2%[12] | 11%[12] |
|
Tumorous glands: | 3+3=6[9] | ||
| Microcystic carcinoma | 11%[12] | On (usually) adjacent acinar adeocarcinoma[13] | |||||
| PIN-like | 1.3%[14] |
|
Tumorous glands:
|
Not recommended[9] | |||
| Non acinar (or mixed acinar/ non-acinar) adenocarcinoma |
Ductal adenocarcinoma | 3% to 12.7%[15][notes 5] | File:Micrograph of typical ductal adenocarcinoma of the prostate.jpg | ||||
| Intraductal adenocarcinoma | 2.8%[17] | File:Micrograph of intraductal carcinoma of the prostate with an infiltrative growth pattern.jpg H&E and CK5/6 |
|||||
| Urothelial carcinoma | 0.7 to 2.8%[19] | File:Urothelial carcinoma in the prostatic urethra, low mag.jpg | Not recommended[9] | ||||
| Small-cell carcinoma | 0.3–2%[21][22][notes 5] | File:Micrograph of small-cell carcinoma of the prostate.jpg |
Half of cases have usual acinar components[9] |
||||
| Mucinous adenocarcinoma | 0.2%[19] | File:Micrograph of mucinous adenocarcinoma of the prostate with Gleason score 7 (3 + 4) with individual well-formed glands and minor component of cribriform glands floating in extracellular mucin.jpg |
|
Tumorous glands: | 4+4=8 for irregular cribriform glands floating in mucin.[9] | ||
| Signet-ring adenocarcinoma | 0.02%[23] | File:Micrograph of signet-ring adenocarcinoma of the prostate.jpg |
|
Tumorous glands: | Not recommended[9] | ||
| Basal-cell carcinoma | 0.01%[24] | Basaloid tumor:
BCC-pattern: |
Not recommended.[9] | ||||
Gleason scoring
Rate the dominant, or most common cell morphology (scored 1—5), in addition to the non-dominant cell pattern with the highest grade (scored 1—5).
-
Gleason pattern 6 (3+3).jpg
-
Gleason pattern 7 (3+4).jpg
-
Gleason pattern 8 (4+4).jpg
-
Gleason pattern 9 (4+5).jpg
-
Gleason pattern 10 (5+5).jpg
Gleason score is as follows:[25]
- Gleason score ≤3: Only individual discrete well-formed glands
- Gleason score 4: Poorly-formed, fused and/or cribriform glands
- Gleason scores 5: Lacks gland formation , or with necrosis
-
Gleason score 6 (3+3)
-
Cribriform pattern: Gleason grade 4
-
Gleason score 7 (3+4) with minor component of cribriform glands
-
Gleason score 8 (4+4) with glomeruloid glands
-
Gleason score 8 (4+4) with irregular cribriform glands
-
Gleason score 8 (4+4) with fused glands with cytoplasmic vacuoles
-
Gleason score 8 (4+4) with poorly-formed glands
-
Gleason score 9 (4+5) with cribriform glands, some with necrosis
-
Gleason score 10 (5+5) with cords of cells
-
Gleason score 10 (5+5) with individual cells
-
Gleason score 10 (5+5) with solid sheets of cells
Grade group
(In a moderately comprehensive report, also state the overall grade group for the adenocarcinoma:[25]
- Grade group 1 (Gleason score ≤6) - Only individual discrete well-formed glands
- Grade group 2 (Gleason score 3+4=7) - Predominantly well-formed glands with a lesser component of poorly-formed, fused and/or cribriform glands
- Grade group 3 (Gleason score 4+3=7) - Predominantly poorly-formed, fused, and/or cribriform glands with a lesser component of well-formed glands
- Grade group 4 (Gleason score 8), either of the following
- Only poorly-formed, fused and/or cribriform glands
- Predominantly well-formed glands with a lesser component that lacks glands
- Predominantly lacking glands with a lesser component of well-formed glands
- Grade group 5 (Gleason scores 9-10): Any area that lacks gland formation, or with necrosis)
Staging
Depending on sample type:
- Multiple biopsy specimens: Adenocarcinoma presence in how many of the biopsies
- Prostatectomy: Stage by TNM:
From the AJCC 7th edition[26] and International Union Against Cancer (UICC) 7th edition.[27]
- Evaluation of the (primary) tumor ('T')
- TX: cannot evaluate the primary tumor
- T0: no evidence of tumor
- T1: tumor present, but not detectable clinically or with imaging
- T1a: tumor was incidentally found in 5% or less of prostate tissue resected (for other reasons)
- T1b: tumor was incidentally found in greater than 5% of prostate tissue resected
- T1c: tumor was found in a needle biopsy performed due to an elevated serum PSA
- T2: the tumor can be felt (palpated) on examination, but has not spread outside the prostate
- T2a: the tumor is in half or less than half of one of the prostate gland's two lobes
- T2b: the tumor is in more than half of one lobe, but not both
- T2c: the tumor is in both lobes but within the prostatic capsule
- T3: the tumor has spread through the prostatic capsule (if it is only part-way through, it is still T2)
- T3a: the tumor has spread through the capsule on one or both sides
- T3b: the tumor has invaded one or both seminal vesicles
- T4: the tumor has invaded other nearby structures
- Evaluation of the regional lymph nodes ('N')
- NX: cannot evaluate the regional lymph nodes
- N0: there has been no spread to the regional lymph nodes
- N1: there has been spread to the regional lymph nodes
- Evaluation of distant metastasis ('M')
- MX: cannot evaluate distant metastasis
- M0: there is no distant metastasis
- M1: there is distant metastasis
- M1a: the cancer has spread to lymph nodes beyond the regional ones
- M1b: the cancer has spread to bone
- M1c: the cancer has spread to other sites (regardless of bone involvement)
- Further information: Evaluation
Report
- Diagnosis
- Gleason score, and optionally grade group
- Extent
- Prostatectomy: Stage.
- Prostate biopsies: Number of biopsies where tumor is found, and percentage of involvement in those cases.<ref group=notes>Percentage of involvement can be estimate by first estimated what percentage of the field-of-view diameter the tumorous area occupies, or how many field-of-view diameters it occupies, divided by how many field-of-view diameters the entire biopsy occupies.
- Any perineural or angiolymphatic invasion.
| (Prostate, left apex, needle biopsy:)
prostatic adenocarcinoma, gleason score 3+3 = 6 (grade group 1), involving 30% of out of one core.
Notes
Main pageReferences
Image sources
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