Primary small cell carcinoma of the pleura: a case report with immunohistochemical and molecular genetic analyses of KIT and PDGFRA genes

Our plain-English summary of Primary small cell carcinoma of the pleura: a case report with immunohistochemical and molecular genetic analyses of KIT and PDGFRA genes, by T. Terada (Medical Oncology, 2010).

The study

• Author: T. Terada
• Journal: Medical Oncology
• Published: 2010;27(4):1119-22
• Type of article: Case report
• Cited by: 14 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

An extremely rare case of primary small cell carcinoma of the pleura with an emphasis on KIT and platelet-derived growth factor receptor-α (PDGFRA) genes is reported here. A 67-year-old man underwent left testicular orchiectomy because of a testicular tumor. The tumor was immunohistochemically shown to be diffuse large B-cell lymphoma. The patient was treated with chemotherapy and radiation and followed up in our hospital. Eight years after the orchiectomy, the patient (75 years old) developed left pleural tumor and pleural effusion, and a biopsy was performed. The biopsy revealed a medullary malignant tumor consisting of small round and spindle cells. The following three possibilities were considered: recurrent lymphoma, mesothelioma, and small cell carcinoma. Immunohistochemically, the tumor cells were positive for cytokeratin, synaptophysin, CD56, KIT, and PDGFRA, but negative for CEA, cytokeratin 5/6, neuron-specific enolase, chromogranin, CD45, CD3, CD20, CD45RO, CD15, CD30, calretinin, WT-1, B72.3, D2-40, and TTF-1. Therefore, a diagnosis of pleural small cell carcinoma was made. A molecular genetic analysis using PCR-direct sequencing identified no mutations of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) genes. The patient was treated with chemotherapy (cisplatin) and radiation (50 Gray). The present case is the first reported case of primary small cell carcinoma of the pleura with an examination of KIT and PDGFRA expressions and KIT and PDGFRA gene mutations.

In plain English

This article is a case report describing one patient, a man treated at a hospital in Shizuoka, Japan. At age 67 he had a testicular tumor removed, which was diagnosed as diffuse large B-cell lymphoma, and he received chemotherapy and radiation. Eight years later, at 75, he had chest pain, and imaging showed a tumor of the left parietal pleura (the lining of the chest wall) with fluid around the lung. Imaging found no tumors elsewhere and none in the lungs. Doctors first suspected the lymphoma had returned. Under the microscope, a biopsy showed small round and spindle-shaped cells. The author considered recurrent lymphoma, mesothelioma and small cell carcinoma. Based on staining tests, the author diagnosed primary small cell carcinoma of the pleura. The tumor showed the proteins KIT (strongly) and PDGFRA (moderately). Genetic testing of the KIT and PDGFRA genes found no mutations in the regions tested. The patient received cisplatin chemotherapy and 50 Gray of radiation. The author concluded that small cell carcinoma arising outside the lung appears to express these proteins without mutations in these genes. The article does not mention any asbestos exposure for this patient and does not report how he fared after treatment.

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 man, treated at a hospital in Shizuoka, Japan. He had diffuse large B-cell lymphoma of the testis at age 67 and developed a left pleural tumor eight years later, at age 75.
• Exposure: No asbestos or other occupational or environmental exposure is reported for this patient. His earlier medical history was lymphoma treated with chemotherapy and radiation.
• Main results:
  • Imaging found no other tumors in the body, and the lungs were free of tumor.
  • The clinical diagnosis before biopsy was recurrent malignant lymphoma.
  • The biopsy showed a malignant tumor made of small round and spindle cells.
  • The tumor cells were positive for cytokeratin, synaptophysin, CD56, KIT and PDGFRA. They were negative for a list of markers that included calretinin, WT-1, D2-40 and TTF-1. A diagnosis of primary pleural small cell carcinoma was made.
  • PDGFRA protein was moderately expressed in the tumor. The figure legend describes KIT expression as strong.
  • PCR-direct sequencing found no mutations in KIT (exons 9, 11, 13 and 17) or PDGFRA (exons 12 and 18).
  • The patient was treated with cisplatin chemotherapy and 50 Gray of radiation. No outcome or follow-up is reported.
• The authors' conclusion: The author concluded that these findings, together with similar earlier reports, suggest that small cell carcinoma arising outside the lung expresses KIT and PDGFRA proteins but has no mutations of the KIT and PDGFRA genes.

Topics

Medical terms in this study, explained in our Lexicon: Carcinoma, Pleura, Platelet-Derived Growth Factor (PDGF), Orchiectomy, Chemotherapy, Pleural Effusion, Biopsy, Spindle Cell.

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