Primary pleural small cell carcinoma with massive pleural effusion: A rare case report

Our plain-English summary of Primary pleural small cell carcinoma with massive pleural effusion: A rare case report, by P. Rabha, J.P. Wisely, A. Jain, et al (International Journal of Surgery Case Reports, 2025).

The study

• Authors: P. Rabha, J.P. Wisely, A. Jain, V. Raina, S. Ahlawat, S. Das
• Journal: International Journal of Surgery Case Reports
• Published: 2025;132:111450
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction And Importance: Lung cancer is the leading cause of cancer-related mortality worldwide, with small cell lung carcinoma (SCLC) accounting for significant morbidity and mortality. While SCLC typically arises from neuroendocrine cells in the central lung, primary pleural small cell carcinoma is exceedingly rare. Its atypical presentation poses diagnostic challenges, emphasizing the need for early recognition and accurate diagnosis to optimize outcomes.

Case Presentation: A 70-year-old male presented with progressive shortness of breath and significant weight loss. Imaging revealed massive pleural effusion. Pleural fluid analysis via pleurocentesis, including cytological evaluation and cell block analysis, revealed features consistent with small cell neuroendocrine carcinoma. Immunohistochemical studies confirmed the diagnosis, with tumor cells positive for pancytokeratin, TTF1, synaptophysin, and INSM1, and negative for Napsin-A, p40, WT1, calretinin, and chromogranin. A Ki-67 proliferation index of >90 % indicated a highly proliferative tumor. Chemotherapy with Carboplatin and Etoposide was initiated, leading to a partial response as evidenced by follow-up PET-CT imaging.

Clinical Discussion: Primary pleural small cell carcinoma is an exceptionally rare and aggressive variant of SCLC. Accurate diagnosis relies on cytological and immunohistochemical analyses to differentiate it from other pleural malignancies, particularly mesothelioma. The high Ki-67 index indicates its aggressive nature. Management follows conventional SCLC protocols, with systemic chemotherapy as the primary treatment modality. The patient's partial response highlights the potential for disease control with prompt intervention.

Conclusion: This case highlights the rarity and aggressive nature of primary pleural small cell carcinoma. Advanced diagnostic techniques and timely treatment are critical.

Copyright © 2025 The Authors. Published by Elsevier Ltd.. All rights reserved.

In plain English

This case report described one patient: a 70-year-old man, reported by doctors in Gurugram, India, who came to an emergency department with worsening shortness of breath. He had nine months of breathlessness and dry cough, had lost 11 kg, and was an ex-smoker with a 12 pack-year history. The article does not mention asbestos exposure. A PET-CT scan showed nodular thickening of the left pleura (the lining around the lung) with a massive fluid build-up, and no mass in the lung. Drained fluid and a pleural biopsy were tested with immunohistochemistry stains. The tumor cells were positive for markers including TTF1 and synaptophysin and negative for others, including WT1 and calretinin, which the authors noted mesothelioma cells are positive for. The diagnosis was small cell neuroendocrine carcinoma. After six cycles of carboplatin and etoposide, given with palliative intent, a follow-up scan showed a partial response. Because no lung source was found, the authors suggested the cancer may have started in the pleura. The results section gives the Ki-67 proliferation index as greater than 60 percent; the abstract says greater than 90 percent.

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 report (single patient)
• Who was studied: One 70-year-old man seen at an emergency department, reported by authors at Fortis Memorial Research Institute, Gurugram, India. He had nine months of shortness of breath with dry cough and 11 kg unintentional weight loss. Dates are not given.
• Exposure: No asbestos exposure is reported for this patient. The only exposure history given is smoking: ex-smoker, 12 pack-years.
• Main results:
  • PET-CT showed nodular thickening of the left pleura with a massive left pleural effusion.
  • No mass was found in the lung.
  • On the cell block, tumor cells were negative for Napsin-A, p40, WT1, calretinin and chromogranin. They were positive for pan-cytokeratin, TTF1, synaptophysin and INSM1.
  • The authors stated that mesothelioma tumor cells are positive for pan-cytokeratin, WT1 and calretinin. This patient's tumor cells were negative for WT1 and calretinin.
  • The Ki-67 proliferation index was reported in the results as greater than 60 %. The abstract gives greater than 90 %.
  • The diagnosis was small cell neuroendocrine carcinoma.
  • Chemotherapy with carboplatin and etoposide was given with palliative intent. After six cycles, a follow-up PET-CT showed a partial response: most pleural nodules and the effusion had reduced.
• The authors' conclusion: The authors suggested the tumor may have originated in the pleura, because standard diagnostic methods found no lung source. They also stated that awareness of this rare presentation is essential.

Topics

Medical terms in this study, explained in our Lexicon: Carcinoma, Pleural Effusion, Lung Cancer, Cell Block, Calretinin, Ki-67, Chemotherapy, Carboplatin.

Related studies

• Pleural small cell carcinoma with massive pleural effusion: A case report — J.G. Jang, M.H. Jang, et al. (2019)
• Small cell carcinoma presenting with massive pleural spread mimicking malignant pleural mesothelioma — T. Takeda, M. Saitoh, et al. (2014)
• Nuclear Brachyury Expression Is Consistent in Chordoma, Common in Germ Cell Tumors and Small Cell Carcinomas, and Rare in Other Carcinomas and Sarcomas: An Immunohistochemical Study of 5229 Cases — M. Miettinen, Z. Wang, et al. (2015)
• Loss of expression of BAP1 is very rare in non-small cell lung carcinoma — J. Andrici, T.R. Parkhill, et al. (2016)
• Small cell mesothelioma: A rare entity and diagnostic pitfall mimicking small cell lung carcinoma on fine-needle aspiration — Y. Zhang, A. Afify, et al. (2016)
• Asbestos Exposure and Development of Pulmonary Pleomorphic Carcinoma in a Non-smoker: A Rare Non-small Cell Lung Cancer — A.L. Alejo, R.A. Patel, et al. (2023)

Browse more research in International Journal of Surgery Case Reports, or return to medical research.