Histomorphological and Immunohistochemical Analysis of Pleural Neoplasms

Our plain-English summary of Histomorphological and Immunohistochemical Analysis of Pleural Neoplasms, by S. Venkatachala, S. Shivakumar, M. Prabhu, et al (Iranian Journal of Pathology, 2018).

The study

• Authors: S. Venkatachala, S. Shivakumar, M. Prabhu, R. Padilu
• Journal: Iranian Journal of Pathology
• Published: 2018;13(2):196-204
• Read it: PubMed · Free full text

Abstract

Background & Objective: Primary pleural neoplasms are rare entities compared with the pleural involvement by metastatic carcinoma.The current study aimed at investigating the complete spectrum of pleural neoplasms and differentiating between them with the aid of immunohistochemistry (IHC).

Methods: Consecutive pleural biopsy specimens positive for a neoplasm, both primary and metastatic, were included in the study. Diagnosis or a differential diagnosis was suggested on histopathology confirmed by a panel of IHC markers such ascytokeratin(AE1/AE3), epithelial membrane antigen (EMA),vimentin, calretinin, CD34, CD99, SMA,bcl2, S100, CK7,CK20,TTF1,GCDFP, HMB45, LCA, synapto-physin, chromogranin, and naspsin.

Results: A total of 35 cases of pleural neoplasms included 15 (42.9%) primary pleural neoplasms and 20 (57.1%) metastatic carcinoma. Synovial sarcoma, malignant mesothelioma (MM), and solitary fibrous tumor (SFT) accounted for 14.2%,11.4%, and 8.5% of metastatic cases, respectively. Epithelioid sarcoma(ES), neuroendocrine carcinoma, and inflammatory myofibroblastic tumor were less common, each contributing to 2.9% of pleural neoplasms. Among the 20 cases of metastatic carcinoma, 13 were from the lung and 7 from the breast. Lung neoplasms metastasizing to the pleura were adenocarcinoma (n=12) and atypical carcinoid (n=1).

Conclusion: Analysis of histopathological pattern along with a panel of appropriate IHC markers distinguished the rare entities of pleural neoplasms essential to determine the prognosis and treatment modality.

In plain English

The authors, pathologists in Bangalore, India, reviewed consecutive pleural biopsies that showed a tumor at a tertiary care hospital from January 2012 to October 2016. Tumors were classified by their appearance under the microscope and confirmed with immunohistochemistry, a set of tissue stains chosen according to cell type. Of 35 cases, 15 (42.9%) were tumors that started in the pleura and 20 (57.1%) were cancers that had spread there from elsewhere. Among all 35 cases, synovial sarcoma made up 5 (14.2%), malignant mesothelioma 4 (11.4%) and solitary fibrous tumor 3 (8.5%). Epithelioid sarcoma, neuroendocrine carcinoma and inflammatory myofibroblastic tumor were one case each. The four mesotheliomas were three epithelioid and one desmoplastic. The authors wrote that all the mesothelioma patients were elderly males with a history of environmental exposure to asbestos. No fiber type or exposure details were given. Of the spread cancers, 13 came from the lung and 7 from the breast. The authors concluded that the microscopic pattern plus a suitable panel of stains distinguished these rare pleural tumors.

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: case series of consecutive pleural biopsy specimens, diagnosed by histopathology and confirmed by immunohistochemistry (IHC)
• Who was studied: 35 consecutive pleural biopsy specimens positive for a primary or metastatic neoplasm, at a tertiary care hospital (authors at Apollo Hospitals Bangalore, India), January 2012 to October 2016
• Exposure: Exposure was not studied. The authors state that the mesothelioma patients had a history of environmental asbestos exposure; no fiber type, source or amount is given.
• Main results:
  • Of 35 pleural neoplasms, 15 (42.9%) were primary pleural neoplasms and 20 (57.1%) were metastatic carcinoma
  • Synovial sarcoma (5 cases, 14.2% of all 35) was the most common primary pleural neoplasm, slightly outnumbering malignant mesothelioma (4 cases, 11.4%); solitary fibrous tumor accounted for 3 cases (8.5%)
  • Epithelioid sarcoma, neuroendocrine carcinoma and inflammatory myofibroblastic tumor were less common, one case each (2.9% each of the pleural neoplasms)
  • The four malignant mesothelioma cases were three epithelioid and one desmoplastic; the epithelioid cases stained for calretinin and cytokeratin 7 and were negative for TTF1, CK20 and HMB45
  • The authors state that all mesothelioma patients were elderly males with a history of environmental asbestos exposure
  • Synovial sarcoma was confirmed by positive staining for vimentin, Bcl2 and CD99, plus CK/EMA in the biphasic cases
  • Of the 20 metastatic carcinomas, 13 came from the lung (12 adenocarcinoma, 1 atypical carcinoid) and 7 from the breast
• The authors' conclusion: The authors concluded that analysis of the histopathological pattern along with a panel of appropriate IHC markers distinguished the rare pleural neoplasms, which they considered essential for determining prognosis and treatment.

Topics

Medical terms in this study, explained in our Lexicon: Neoplasm, Carcinoma, Immunohistochemistry, Pleural Biopsy, Differential Diagnosis, Histopathology, Epithelial Membrane Antigen (EMA), Calretinin.

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