Surgical pathology of lung cancer

Our plain-English summary of Surgical pathology of lung cancer, by M.K. Rezaei, N.J. Nolan, A.M. Schwartz (Seminars in Respiratory and Critical Care Medicine, 2013).

The study

• Authors: M.K. Rezaei, N.J. Nolan, A.M. Schwartz
• Journal: Seminars in Respiratory and Critical Care Medicine
• Published: 2013;34(6):770-86
• Type of article: Review
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

The diagnosis, treatment, and management of lung tumors represent a complex set of decision algorithms and require the cooperation and interaction of a team of experts and support systems. The surgical pathologist, an early, important member of the diagnostic team, uses clinical and radiological evidence to differentiate benign from malignant tumors and renders a unique diagnosis that provides both prognostic and treatment information. Using routine histopathologic criteria, histochemical and immunohistochemical stains, and molecular and genetic testing, surgical pathologists and cytopathologists may distinguish between small cell and other bronchogenic carcinomas, separate adenocarcinomas from squamous cell carcinomas, differentiate between pleural carcinomas and diffuse malignant mesotheliomas, and discriminate among the varieties of neuroendocrine carcinomas. Among adenocarcinomas, the pathological examination stratifies those tumors with absent or minimal central invasive cores that have an excellent prognosis from the more common adenocarcinomas with larger invasive components. These distinctions are necessary based on differences in tumor biology, response to therapy, and prognosis for these different histological types. Histopathologic analysis should attempt to provide a precise diagnosis and limit the usage of the term non-small cell carcinoma. The team approach also enables the optimal use of tumor tissue for diagnostic purposes as well as molecular genetic testing and the discovery of targetable sites for therapeutic management. Though low-stage tumors tend to be initially treated with surgical resection, more advanced stages will be approached with limited tissue acquisition, necessitating a strategy for best practices of scarce tissue resources. The awareness of diagnostic modalities and tissue handling by all members of the team ensures the best patient-centered care.

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In plain English

This article was a narrative review by pathologists at The George Washington University Medical Center in Washington, DC. It reported no new patient or exposure data. It described how surgical pathologists diagnose lung tumors using routine microscope slides, chemical and antibody (immunohistochemical) stains, and molecular tests. It covered adenocarcinoma, squamous cell carcinoma, neuroendocrine tumors, large cell and sarcomatoid carcinomas, salivary gland-type tumors, and malignant mesothelioma. Citing other publications, the review stated that in industrialized countries most pleural mesotheliomas are associated with occupational asbestos fiber exposure, with a latency period of more than 20 years, and that pleural plaques usually come before the tumor. It named no specific fiber types. It described antibody stain panels used to tell mesothelioma apart from adenocarcinoma. It noted that cytokeratin staining alone does not reliably separate reactive (benign) from malignant mesothelial cells. It described microscope features and antibody stains as usually sufficient to diagnose malignant mesothelioma, and called electron microscopy, which separates mesothelioma from adenocarcinoma, the gold standard. The authors recommended that the surgical pathologist be part of the diagnostic team and that a synoptic (standardized) report be used.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative review of the surgical pathology of lung and pleural tumors
• Who was studied: No study population; a review of published literature written by authors at The George Washington University Medical Center, Washington, DC
• Exposure: Not studied. Occupational asbestos fiber exposure is mentioned only as background for pleural mesothelioma, citing other publications; no fiber types are named
• Main results:
  • The review stated, citing other publications, that in industrialized countries most pleural mesotheliomas are associated with occupational asbestos fiber exposure and develop after a latency period of more than 20 years
  • The review stated that pleural mesothelioma may occur with or without pulmonary asbestosis, and that pleural plaques usually precede the malignancy
  • The review stated that between a quarter and a third of mesotheliomas have a biphasic pattern of mixed epithelial and sarcomatoid elements
  • The review described markers typically positive in mesothelioma and negative in adenocarcinoma (WT-1, CK 5/6, calretinin, thrombomodulin, mesothelin), and the reverse pattern (CEA, CD15, TTF-1)
  • The review stated that cytokeratin staining on its own does not reliably distinguish reactive from malignant mesothelial cells
  • The review stated that morphological features and immunohistochemical assays are usually sufficient for the diagnosis of malignant mesothelioma
  • The review described ultrastructural (electron microscope) identification of long thin microvillous processes as the gold standard for diagnosing mesothelioma, in contrast to the short blunt processes and basal lamina of adenocarcinoma
  • For lung cancer, the review stated that pathologists should try to avoid the diagnosis 'non-small cell lung carcinoma, not otherwise specified'
• The authors' conclusion: The authors recommended that the surgical pathologist be part of the diagnostic team and that a synoptic report be used alongside the surgical pathology report

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Pathology, Lung Cancer, Bronchogenic Carcinoma, Adenocarcinoma, Squamous Cell Carcinoma, Carcinoma, Malignant Mesothelioma, Prognosis.

Related studies

• Diagnostic surgical pathology in lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines — A.M. Schwartz, M.K. Rezaei (2013)
• Germline BAP1-positive patients: the dilemmas of cancer surveillance and a proposed interdisciplinary consensus monitoring strategy — P. Star, A. Goodwin, et al. (2018)
• Surgical pathology of primary cardiac and pericardial tumors — C. Basso, M. Valente, et al. (1997)
• GATA3: a multispecific but potentially useful marker in surgical pathology: a systematic analysis of 2500 epithelial and nonepithelial tumors — M. Miettinen, P.A. McCue, et al. (2014)
• Pathology of carcinoma of the lung associated with asbestos exposure — M. Kannerstein, J. Churg (1972)
• Improving the Accuracy of Mesothelioma Diagnosis in China — Z. Guo, M. Carbone, et al. (2017)

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