CONTENTS:

6.1 The Pathology Report
6.1.1 The Pathology Report as the Basis for Treatment Selection
6.1.2 The Content of the Pathology Report

Forward to 6B Tissue Sampling .  Back to 5F Pulmonary Lymphomas

Last night I almost had a threesome; I only needed two more people.

Section 6 will explain diagnostic tests on lung tissue samples and the process of examination and reporting by the Pathologist.   When a patient receives a copy of the diagnostic pathology report, there may reference to ‘special stains’ or ‘tumor markers’ or ‘immunohistochemistry (IHC)’ or ‘molecular tests.’

In the past, the histopathology diagnosis of lung cancer and the different types of lung cancer has been based upon the microscopic examination of small biopsies.  Recently, there has been an increase in the use of ‘targeted‘ lung cancer treatments.  The identification of these mutations can be challenging on small biopsy samples.  There is also an increase in the incidence of adenocarcinoma, as opposed to squamous carcinoma;  the complex classification of this type of non small cell lung cancer (NSCLC), has led to greater emphasis on the importance of making the diagnosis on a tissue biopsy.

6.1 The Pathology Report

 
The Histopathologist (or Surgical Pathologist) is a medical practitioner with specialist training, who examines individual cells (cytology), small tissue samples (biopsies) and whole tumor samples (resections) from patients.  These tissue samples are obtained from the primary tumor site in the lung or metastatic deposits.   Very thin (3-6m) tissue ‘fixed’ or preserved tissue sections are cut on glass slides and then stained with dyes that show the cell and tissue morphology.   These slides are examined under the light microscope by the Pathologist, who will then write a diagnostic report for the treating physicians and the patient.
 

Figure 6.1  The Pathologist and the Light Microscopy
(Histology or Histopathology)

I thought all microscopes were quite light – I could carry mine quite easily.

I’m on a light diet. I eat by daylight, moonlight and refrigerator light.

6.1.1 The Pathology Report as the Basis for Treatment Selection

 
‘Personalized medicine‘ has developed in the past decade for patients with Non Small-Cell Cancer (NCLC) and its use is expected to increase in the future.  Pathology is important in supporting this approach to treatment decision-making, as it results in histological ‘sub-typing’ of the lung tumor.   This tumor sub-typing for treatment relies upon tissue-based techniques performed in the diagnostic clinical pathology laboratory. These tissue-based techniques include ‘predictive’ immunohistochemistry (IHC), fluorescence in-situ hybridization (FISH) analysis and the assessment of relevant tissue ‘biomarkers‘ (targets for therapy).

The Pathologist works within a multidisciplinary team (MDT) to ensure that the most appropriate pathology report is provided for every patient with lung cancer. A written pathology report follows cytology sampling, a lung biopsy or a lung surgical excision procedure. The patient’s treating physician will receive the pathology report withing seven days of the biopsy or surgical procedure. The pathology report will contain the diagnosis of any abnormality.

Forensic pathology is the best. Their patients are the coolest!

6.1.2 The Content of the Pathology Report

 
The pathology report includes patient information, morphological description of the cells and tissues examined, the results of any ‘special’ tests or ‘special stains’ and, finally, the tissue diagnosis.  In unusual, rare or difficult cases patients receive a ‘differential diagnosis’ with a recommendation for further tests on the cells or the tissue.

A pathology report begins with a ‘gross’ or ‘macroscopic’ description of the tissue sample (size, weight, focal or diffuse abnormality, measurements including excision margins). The pathology report includes the following:

• Patient information: name, date of birth, biopsy date
• Gross description: color, weight, and size of tissue as seen by the naked eye
• Microscopic description: how the sample looks under a microscope and how it compares with normal cells
• Diagnosis: type of tumor and grade (how abnormal the cells look under a microscope and how quickly the tumor is likely to grow and spread)
• Tumor size: measured in centimeters
• Tumor margins: there are three possible findings when the biopsy sample is the entire tumor:
• Positive margins mean that cancer cells are present at the edge of the tissue specimen.
• Negative, not involved, clear, or free margins mean that no cancer cells are present at the outer edge
• Close margins are neither negative nor positive
• Other information: usually information about samples sent for ‘special stains’ or other tests or a second opinion
• Pathologist’s signature and name and address of the laboratory

Figure 6.2 The Pathologist and the Pathology Report

The Pathologist receives the lung tissue and describes the ‘gross’
appearance and ensures that the tissue is fixed. B. Fixed and
processed tissue is sectioned by the Lab Technician who cuts
3 to 6 micron thin sections on to glass slides and stains the sections.
C. The Pathologist looks at the lung tissue sections on the glass slide
using light microscopy.

Did you hear about the outgoing pathologist?
He stares at YOUR shoes when he talks!

References:

 
Travis WD, IASLC Staging Committee. (2009) Reporting lung cancer pathology specimens. Impact of the anticipated 7th Edition TNM classification based on recommendations of the IASLC Staging Committee. Histopathology. Jan;54(1):3-11. (Retrieved 25^th April 2015): http://www.ncbi.nlm.nih.gov/pubmed/19187176

Kerr KM. (2009) Pulmonary adenocarcinomas: classification and reporting. Histopathology. Jan;54(1):12-27 (Retrieved 25^th April 2015): http://www.ncbi.nlm.nih.gov/pubmed/19187177
 

More references for this section are on this page .

Patient Information:

 
Cancer.org. Understanding Your Pathology Report. (Retrieved 10^th Feb 2015): http://www.cancer.org/treatment/understandingyourdiagnosis/understandingyourpathologyreport/lungpathology/lung-cancer-pathology

National Cancer Institute  Pathology Reports (Retrieved 24^th April 2015):  http://www.cancer.gov/cancertopics/diagnosis-staging/diagnosis/pathology-reports-fact-sheet
 

More patient information for this section is on this page .

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