Alveolar rhabdomyosarcomas involving serous cavity fluid specimens exhibit diverse cytomorphologies: A case report and review of the literature

Our plain-English summary of Alveolar rhabdomyosarcomas involving serous cavity fluid specimens exhibit diverse cytomorphologies: A case report and review of the literature, by R.M. Jones, C.J. VandenBussche (Diagnostic Cytopathology, 2020).

The study

• Authors: R.M. Jones, C.J. VandenBussche
• Journal: Diagnostic Cytopathology
• Published: 2020;48(11):1155-1161
• Type of article: Case report, Review
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Involvement of serous cavity specimens by alveolar rhabdomyosarcoma (ARMS) is a rare event and only a few case reports have been reported in the literature, with conflicting cytomorphologic patterns. Herein, we report on a 41-year-old man with no significant past medical history who presented with pancytopenia and shortness of breath and was found to have widely metastatic sinonasal alveolar rhabdomyosarcoma, including involvement of the pleura. The pleural fluid specimen was cellular and contained ARMS cells in small-to-medium sized three-dimensional fragments that resembled an adenocarcinoma or mesothelioma, and numerous single cells were seen in the background. The individual tumor cells demonstrated variable morphology; all were large, with varying degree of cytoplasm, and multinucleated cells were commonly seen in the background. The cells were negative for calretinin and claudin-4 and were positive for myogenin, confirming the diagnosis. Given the cytomorphologic diversity of ARMS seen in serous fluid specimens, patient history and the use of confirmatory immunostains are essential.

© 2020 Wiley Periodicals LLC.

In plain English

This article is a case report with a discussion of earlier published reports. It does not study asbestos exposure; mesothelioma appears only as a cancer the tumor cells resembled. The authors described a 41-year-old man whose only past condition was well-controlled type 2 diabetes. He came to hospital with shortness of breath, weakness and fatigue, fluid around both lungs (pleural effusions) and low blood counts. A bone marrow biopsy, and genetic testing that found a PAX3/FOXO1 translocation, confirmed alveolar rhabdomyosarcoma, a muscle-type cancer. Imaging showed a 3.8 cm mass in the left nasal cavity, suspicious lymph nodes, and nodules on the pleura. The pleural fluid contained many tumor cells, lying singly and in small-to-medium three-dimensional clusters. Their appearance varied within the same sample, and the authors wrote that they resembled adenocarcinoma or mesothelioma. Stains were negative for calretinin and claudin-4 and positive for myogenin, confirming the diagnosis. The authors noted that earlier reports described differing appearances for this tumor in body fluids. They concluded that patient history and confirmatory stains are essential.

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 with a discussion of previously published case reports and case series
• Who was studied: one 41-year-old man, previously noted only for well-controlled type 2 diabetes, treated at the authors' institution (Johns Hopkins, Baltimore) after transfer from a community hospital
• Main results:
  • In the patient's bone marrow biopsy, the atypical cells were positive for desmin, myogenin, CD56 and SMA
  • Cytogenetic testing of the bone marrow showed a complex karyotype in 9 of the 18 analyzed metaphases, including the PAX3/FOXO1 translocation that confirmed alveolar rhabdomyosarcoma
  • Imaging in the patient showed a 3.8 cm mass in the left nasal cavity, suspicious mediastinal and hilar lymph nodes, and large bilateral pleural effusions with pleural nodularity
  • The patient's pleural fluid was highly cellular, with single tumor cells and small-to-medium irregular three-dimensional clusters
  • The tumor cells varied in appearance within the specimen: some were multinucleated with wreath-like nuclei, and others looked rhabdoid or histiocytoid. The authors stated that the cells better resembled adenocarcinoma and mesothelioma
  • On the cell block, the patient's tumor cells were negative for calretinin and claudin-4 and showed strong, diffuse nuclear staining for myogenin
• The authors' conclusion: The authors concluded that because alveolar rhabdomyosarcoma looks so varied in serous fluid specimens, patient history and confirmatory immunostains are essential

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Pleura, Adenocarcinoma, Mesothelioma, Calretinin, Claudin-4, Serous Fluid.

Related studies

• MicroRNA profiling in serous cavity specimens: Diagnostic challenges and new opportunities — L. Nicolè, F. Cappello, et al. (2019)
• Claudin-4 immunohistochemistry is a useful pan-carcinoma marker for serous effusion specimens — M. Vojtek, M.D. Walsh, et al. (2019)
• Lectin binding properties of cells from serous effusion and peritoneal washing specimens — P.W. Shield (1989)
• Utility of HBME-1 immunostaining in serous effusions — V. Ascoli, C. Carnovale-Scalzo, et al. (1997)
• Diagnostic use of muscle markers in the cytologic evaluation of serous fluids — A.M. Afify, B.M. Al-Khafaji, et al. (2002)
• Current applications of molecular testing on body cavity fluids — D. Pinto, F. Schmitt (2020)

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