Lung adenocarcinoma
Author:
Mikael Häggström [note 1]
Contents
Comprehensiveness
On this resource, the following formatting is used for comprehensiveness:
- Minimal depth
- (Moderate depth)
- ((Comprehensive))
Presentation
Microscopic examination
Adenocarcinoma diagnosis
Lepidic and/or acinar patterns (see below) strongly support the adenocarcinoma diagnosis, otherwise also consider other kinds of lung tumor. For more solid patterns, mainly consider the differential diagnosis of squamous-cell carcinoma (SCC) of the lung. If uncertain, the most useful immunostains are:
p63: Where a positive stain (pictured) indicates SCC rather than lung adenocarcinoma (or small-cell carcinoma).[notes 1]
TTF-1: Is almost always negative in squamous-cell carcinoma (as pictured, with positive staining in surrounding type II alveolar pneumocytes). In contrast, TTF-1 is generally positive in lung adenocarcinomas (and small-cell carcinomas).[2]
Invasiveness
- An adenocarcinoma in situ is defined as a tumour of ≤ 3 cm with pure lepidic pattern but no lymphatic, vascular or pleural invasion and no tumor necrosis.[3]
- Minimally invasive adenocarcinoma: a small (≤3 cm), solitary tumour with predominant alveolar epithelial appearance (lepidic growth), as in situ adenocarcinoma of the lung, with a zone of focal invasion of the stroma with a size inferior to 5 mm.[3] It has no lymphatic, vascular or pleural invasion and no tumor necrosis.
- Invasive adenocarcinoma: Tumor of larger size or focus of invasion, or with lymphatic, vascular, pleural invasion or tumor necrosis.
Predominant pattern
For invasive adenocarcinomas, generally specify the pattern (mainly lepidic, acinar, papillary, micropapillary, solid predominant or "predominant subtype cannot be determined).
Lung adenocarcinoma, with lepidic pattern shown, wherein tumors cells cover alveolar walls.
Lung adenocarcinoma, with acinar pattern.
Lung adenocarcinoma, with solid pattern.
Degree of differentiation
Lung adenocarcinomas may be classified as follows:[4]
Well differentiated | Solid pattern< 90% and mild/moderate atypia |
Moderately differentiated |
|
Poorly differentiated | Solid pattern ≥ 90% and severe atypia |
Staging
Specify:
- Tumor size
If the tumor has both lepidic and invasive components, specify the maximum dimension of each.
- Growth into adjacent structures
Notable adjacent structures possibly involved are:[5]
- Parietal pleura
- Main bronchus
- Hilar soft tissues
- Organs of the mediastinum (specify where possible)
Classification
Staging of non-small-cell lung cancers (AJCC, 8th Ed.):[6]
T category | T criteria |
---|---|
TX | Primary tumor cannot be assessed, or tumor proven by the presence of malignant cells in sputum or bronchial washings, but not visualized by imaging or bronchoscopy. |
T0 | No evidence of primary tumor |
Tis | Carcinoma in situ Squamous cell carcinoma in situ (SCIS) Adenocarcinoma in situ (AIS): Adenocarcinoma with pure lepidic pattern, ≤3 cm in greatest dimension |
T1 | Tumor ≤ in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic invasion more proximal than the lobar bronchus (i.e., not in the main bronchus). |
T1mi | Minimally invasive adenocarcinoma: Adenocarcinoma (≤3 cm in greatest dimension) with a predominantly lepidic pattern and ≤5 mm invasion in greatest dimension. |
T1a | Tumor ≤1 cm in greatest dimension. It also includes a superficial, spreading tumor of any size whose invasive component is limited to the bronchial wall and may extend proximal to the main bronchus (but these are uncommon) |
T1b | Tumor >1 cm but ≤2 cm in greatest dimension |
T1c | Tumor >2 cm but ≤3 cm in greatest dimension |
T2 | Tumor >3 cm but ≤5 cm or having any of the following features:
T2 tumors with these features are classified as T2a if ≤4 cm or if the size cannot be determined and T2b if >4 cm but ≤5 cm. |
T2a | Tumor >3 cm but ≤4 cm in greatest dimension |
T2b | Tumor >4 cm but ≤5 cm in greatest dimension |
T3 | Tumor >5 cm but <7 cm in greatest dimension or directly invading any of the following: Parietal pleura (PL3), chest wall (including superior sulcus tumors), phrenic nerve, parietal pericardium; or separate tumor nodule(s) in the same lobe as the primary. |
T4 | Tumor >7 cm or tumor of any size invading one or more of the following: Diaphragm, mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, or carina. Separate tumor nodule(s) in an ipsilateral lobe different from that of the primary. |
N category | N criteria |
---|---|
NX | Regional lymph nodes cannot be assessed |
N0 | No regional lymph node metastasis |
N1 | Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension. |
N2 | Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s) |
N3 | Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph nodes(s) |
M category | M criteria |
---|---|
M0 | No distant metastasis |
M1 | Distant metastasis |
M1a | Separate tumor nodule(s) in a contralateral lobe; tumor with pleural or pericardial nodes or malignant pleural or pericardial effusion (but note that in a few patients, effusions are negative for tumor in multiple microscopic examinations, and the fluid is non-bloody and is not an exudate, and in such cases the effusion should be excluded as a staging descriptor). |
M1b | Single extrathoracic metastasis in a single organ (including involvement of a single nonregional node) |
M1c | Multiple extrathroracic metastases in a single organ or in multiple organs. |
When T is... | And N is... | And M is... | Then the stage group is... |
---|---|---|---|
TX | N0 | M0 | Occult carcinoma |
Tis | N0 | M0 | 0 |
T1mi | N0 | M0 | 1A1 |
T1a | N0 | M0 | |
T1a | N1 | M0 | IIB |
T1a | N2 | M0 | IIIA |
T1a | N3 | M0 | IIIB |
T1b | N0 | M0 | IA2 |
T1b | N1 | M0 | IIB |
T1b | N2 | M0 | IIIA |
T1b | N3 | M0 | IIIB |
T1c | N0 | M0 | IA3 |
T1c | N1 | M0 | IIB |
T1c | N2 | M0 | IIIa |
T1c | N3 | M0 | IIIB |
T2a | N0 | M0 | IB |
T2a | N1 | M0 | IIB |
T2a | N2 | M0 | IIIA |
T2a | N3 | M0 | IIIB |
T2b | N0 | M0 | IIA |
T2b | N1 | M0 | IIB |
T2b | N2 | M0 | IIIA |
T2b | N3 | M0 | IIIB |
T3 | N0 | M0 | IIB |
T3 | N1 | M0 | IIIA |
T3 | N2 | M0 | IIIB |
T3 | N3 | M0 | IIIC |
T4 | N0 | M0 | IIIA |
T4 | N1 | M0 | IIIA |
T4 | N2 | M0 | IIIB |
T4 | N3 | M0 | IIIC |
Any T | Any N | M1a | IVA |
Any T | Any N | M1b | IVA |
Any T | Any N | M1c | IVB |
Further workup
Metastasis versus primary tumor
If a clearly lepidic pattern is seen in association with a tumor, a primary lung tumor can be reported without immunohistochemistry. Otherwise, (look at any related radiology studies), and look for clues in any differentiation of the tumor. In a single undifferentiated lung adenocarcinoma, and there is no evidence of a primary tumor elsewhere in the body, perform immunohistochemistry for TTF-1, (Napsin A), ((broad spectrum cytokeratin marker such as CK AE1/AE3, CK 7 and CK 20)). The presence of multiple tumors indicates an evaluation as a metastasis. Further information: Metastasis
Molecular workup
For primary lung non-small cell carcinoma (NSCLC) stages IB - IV (such as being more than 3 cm in size), generally perform full next generation sequencing panel (DNA and RNA) with PDL-1 immunostaining. For an advanced stage NSCLC that is not a candidate for biopsy or re-biopsy, a viable alternative is “liquid biopsy” on peripheral blood for circulating tumor DNA.[7]
Notes
- ↑ p63 can distinguish SCC from adenocarcinoma with 85% sensitivity, 95% specificity, 94.4% PPV, and 86.4% NPV, and distinguish SCC from small-cell carcinoma with 85% sensitivity, 100% specificity, 100% PPV, and 87% NPV. Reference:
- Jafarian AH, Gharib M, Mohammadian Roshan N, Sherafatnia S, Omidi AA, Bagheri S (2017). "The Diagnostic Value of TTF-1, P63, HMWK, CK7, and CD56 Immunostaining in the Classification of Lung Carcinoma. ". Iran J Pathol 12 (3): 195-201. PMID 29531543. PMC: 5835366. Archived from the original. .
- ↑ For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
Main page
References
- ↑ Image by Mikael Häggström, MD. Source for findings: Caroline I.M. Underwood, M.D., Carolyn Glass, M.D., Ph.D.. Lung - Small cell carcinoma. Pathology Outlines. Last author update: 20 September 2022}}
- ↑ Jafarian AH, Gharib M, Mohammadian Roshan N, Sherafatnia S, Omidi AA, Bagheri S (2017). "The Diagnostic Value of TTF-1, P63, HMWK, CK7, and CD56 Immunostaining in the Classification of Lung Carcinoma. ". Iran J Pathol 12 (3): 195-201. PMID 29531543. PMC: 5835366. Archived from the original. .
- ↑ 3.0 3.1 Lambe, Gerard; Durand, Michael; Buckley, Anne; Nicholson, Siobhan; McDermott, Ronan (2020). "Adenocarcinoma of the lung: from BAC to the future ". Insights into Imaging 11 (1). doi: . ISSN 1869-4101.
- ↑ Barletta, Justine A.; Yeap, Beow Y.; Chirieac, Lucian R. (2010). "Prognostic significance of grading in lung adenocarcinoma ". Cancer 116 (3): 659–669. doi: . ISSN 0008543X.
- ↑ . Protocol for the Examination of Specimens From Patients With Primary Non-Small Cell Carcinoma, Small Cell Carcinoma, or Carcinoid Tumor of the Lung. Version: Lung 4.0.0.2. Protocol Posting Date: June 2017. College of American Pathologists.
- ↑ Amin, Mahul (2017). AJCC cancer staging manual
(8 ed.). Switzerland: Springer. ISBN 978-3-319-40617-6. OCLC 961218414.
- For access, see the Secrets chapter of Patholines.
- Copyright note: The AJCC, 8th Ed. is published by a company in Switzerland, and the tables presented therein are Public Domain because they consist of tabular information without literary or artistic innovation, and therefore do not fulfil the inclusion criterion of the Swiss Copyright Act (CopA) which applies to "literary and artistic intellectual creations with individual character" (see Federal Act on Copyright and Related Rights (Copyright Act, CopA) of 9 October 1992 (Status as of 1 January 2022)). - ↑ . National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology (NCCN Guidelines) - Non-Small Cell Lung Cancer. Version 3.2024. Section: Principles of molecular and biomarker analysis (2024-03-12).
Image sources
- ↑ Image(s) by: Mikael Häggström, M.D. Public Domain
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