Metastatic proximal epithelioid sarcoma in pleural effusion: cytopathologic findings and differential diagnosis

Our plain-English summary of Metastatic proximal epithelioid sarcoma in pleural effusion: cytopathologic findings and differential diagnosis, by H. Guan, F. Haque, S.Z. Ali (Diagnostic Cytopathology, 2013).

The study

• Authors: H. Guan, F. Haque, S.Z. Ali
• Journal: Diagnostic Cytopathology
• Published: 2013;41(6):542-5
• Type of article: Case report
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We present a rare occurrence of metastatic proximal epithelioid sarcoma (PES) in the pleural effusion of a 23-year-old man, developed within one year of diagnosis in his gluteal soft tissue. The cytologic and immunoperoxidase findings are described. PES, due to its epithelioid morphology, can be confused with more common cancers in effusions such as adenocarcinoma and mesothelioma. PES is an aggressive neoplasm that differs clinically and pathologically from conventional epithelioid sarcoma. Knowledge of its cytomorphology in serous cavity effusions, a patient's clinical history and ancillary studies may lead to an accurate diagnosis.

Copyright © 2011 Wiley Periodicals, Inc.

In plain English

This brief report described one patient: a 23-year-old man whose proximal epithelioid sarcoma (PES), a rare, aggressive soft-tissue cancer, spread to the fluid around his lungs. The article does not discuss asbestos; mesothelioma appears only as a cancer that PES can be mistaken for. The patient's 5.8 cm tumor of the left buttock had been treated with surgery, radiation and chemotherapy. One year later, a CT scan of the pelvis showed a 15 cm mass involving the left iliac bone, and a chest X-ray showed fluid around both lungs. The fluid contained scattered cancer cells among reactive mesothelial cells. These cancer cells stained positive for EMA, cytokeratin CAM 5.2, vimentin and CD34 and negative for calretinin. They were judged consistent with spread from the known buttock tumor. The authors stated that, to their knowledge, this was the first account of PES in pleural fluid. They concluded that the fluid findings matched the original tumor, and that the cells' features, the clinical history and additional tests may lead to an accurate diagnosis.

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 23-year-old man with proximal epithelioid sarcoma of the left gluteal (buttock) soft tissue, treated with wide local excision, radiation and chemotherapy. The article does not state where or when the patient was treated.
• Exposure: No asbestos or other environmental or occupational exposure was studied or mentioned. Mesothelioma is mentioned only as a cancer that PES in effusions can be confused with.
• Main results:
  • One year after diagnosis, a CT scan of the patient's pelvis showed a 15 cm mass involving the adjacent left iliac bone, with extensive pelvic lymph node enlargement.
  • The patient's chest X-ray showed fluid around both lungs (bilateral pleural effusions).
  • The patient's pleural fluid contained loosely scattered (discohesive) malignant epithelioid cells among reactive mesothelial cells, chronic inflammatory cells and histiocytes.
  • The malignant cells in the fluid stained positive for EMA, cytokeratin CAM 5.2, vimentin and CD34, and negative for calretinin.
  • The cell features together with the staining results were judged consistent with metastatic epithelioid sarcoma from the patient's known left gluteal primary tumor.
  • Review of the previously removed primary tumor showed a solid, sheet-like growth of large rhabdoid-type cells.
• The authors' conclusion: The authors stated that, to their knowledge, this was the first account of metastatic PES in pleural effusion. They concluded that the fluid findings correlated well with the resected primary tumor, and that knowledge of the cell features, the patient's clinical history and ancillary studies may lead to an accurate diagnosis.

Topics

Medical terms in this study, explained in our Lexicon: Epithelioid, Sarcoma, Pleural Effusion, Differential Diagnosis, Adenocarcinoma, Mesothelioma, Neoplasm.

Related studies

• A case of pleural epithelioid sarcoma of proximal type presenting as malignant pleural mesothelioma — G.A. Madsen, T.R. Rasmussen, et al. (2013)
• Expression of E-cadherin in bone and soft tissue sarcomas: a possible role in epithelial differentiation — H. Sato, T. Hasegawa, et al. (1999)
• Application of markers in the diagnosis of soft tissue tumours — P.J. Roholl, A.S. De Jong, et al. (1985)
• Cytological differential diagnosis among adenocarcinoma, epithelial mesothelioma, and reactive mesothelial cells in serous effusions by immunocytochemistry — X.Y. Su, G.D. Li, et al. (2011)
• Imaging findings from a case of pleural low-grade fibromyxoid sarcoma similar to mesothelioma with pleural effusion — W. Liang, S. Xu (2016)
• Malignant peritoneal mesothelioma with lower extremity metastasis: PET/CT imaging — B.B. Le, B.D. Nguyen (2015)

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