Rapidly progressing metastatic malignant melanoma mimicking primary pleural tumor: A case report

Our plain-English summary of Rapidly progressing metastatic malignant melanoma mimicking primary pleural tumor: A case report, by C. So, T. Yoshida, T. Mizuno, et al (Thoracic Cancer, 2022).

The study

• Authors: C. So, T. Yoshida, T. Mizuno, Y. Yatabe, Y. Ohe
• Journal: Thoracic Cancer
• Published: 2022;13(9):1423-1426
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant melanoma is the most aggressive skin cancer that originates from melanocytes. Primary or metastatic pleural melanoma shares clinical and imaging characteristics with primary pleural tumors, such as pleural mesothelioma. Identification of the primary site can be challenging to distinguish between primary and secondary melanomas. We report a case of a 46-year-old woman with metastatic, rapidly progressing pleural melanoma mimicking primary pleural tumor. The metastatic pleural tumor from a primary cutaneous melanoma was diagnosed by reevaluating a previous surgical specimen. When evaluating patients with pleural melanoma, the primary site should be reevaluated to distinguish between primary and secondary melanomas.

© 2022 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

In plain English

This case report from the National Cancer Center Hospital in Tokyo, Japan, described one 46-year-old woman whose cancer looked like a primary pleural tumor (one starting in the lining around the lung, such as pleural mesothelioma) but turned out to be melanoma that had spread from the skin. She had worsening shortness of breath and cough. A CT scan showed a large right-sided pleural tumor with a large amount of fluid. A needle sample led to a diagnosis of melanoma. Three years earlier, another hospital had removed an 8-mm skin mass in front of her ear and called it atypical melanocytic proliferation, not melanoma. When the authors re-examined that specimen, they found melanoma. She was first treated with nivolumab plus ipilimumab, but the tumor grew rapidly. The tumor was found to carry a BRAF V600E mutation, so she was switched to dabrafenib plus trametinib. The tumor partly responded, then progressed 5 months after that treatment began. The authors concluded that in patients with pleural melanoma, the original site should be re-examined to tell primary from secondary melanoma. The article does not discuss asbestos.

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 (one patient)
• Who was studied: One 46-year-old woman with worsening shortness of breath (dyspnea) and cough, treated at the National Cancer Center Hospital, Tokyo, Japan; dates of care not given
• Main results:
  • Chest CT showed a large right-sided pleural tumor with heterogeneous contrast enhancement and massive pleural effusion in this patient
  • Endobronchial ultrasound-guided needle aspiration led to a histological diagnosis of melanoma
  • An 8-mm preauricular skin mass removed 3 years earlier at another hospital had been diagnosed as atypical melanocytic proliferation, not melanoma; on review the authors identified melanoma, and the patient was diagnosed with a metastatic pleural tumor from a primary cutaneous melanoma
  • After nivolumab (1 mg/kg) plus ipilimumab (3 mg/kg), the tumor rapidly progressed and filled the right chest cavity
  • After switching to dabrafenib (300 mg/day) plus trametinib (2 mg/day) because the tumor was BRAF V600E mutation positive, the pleural tumor partially responded
  • The tumor progressed 5 months after dabrafenib and trametinib were started
• The authors' conclusion: The authors concluded that when evaluating patients with pleural melanoma, the primary site should be re-evaluated to distinguish primary from secondary melanomas

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma.

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