Case Report
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. May 24, 2019; 10(5): 213-221
Published online May 24, 2019. doi: 10.5306/wjco.v10.i5.213
Clear cell sarcoma in unusual sites mimicking metastatic melanoma
Ifeyinwa E Obiorah, Metin Ozdemirli
Ifeyinwa E Obiorah, Metin Ozdemirli, Department of Pathology, Medstar Georgetown University Hospital, Washington, DC 20007, United States
Author contributions: Obiorah IE and Ozdemirli M contributed to the acquisition of data and the writing and revision of the manuscript.
Informed consent statement: Consent was obtained from the patients prior to study enrollment.
Conflict-of-interest statement: Both authors declare that they have no conflicts of interests.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Ifeyinwa E Obiorah, MD, PhD, Staff Physician, Department of Pathology, Medstar Georgetown University Hospital, 3800 Reservoir Road NW, Washington, DC 20007, United States. ifeyinwa.e.obiorah@gunet.georgetown.edu
Telephone: +1-202-3843639 Fax: +1-202-6878935
Received: January 25, 2019
Peer-review started: January 25, 2019
First decision: January 29, 2019
Revised: February 15, 2019
Accepted: March 16, 2019
Article in press: March 16, 2019
Published online: May 24, 2019
Abstract
BACKGROUND

Clear cell sarcoma is an aggressive rare malignant neoplasm with morphologic and immunohistochemical similarities to malignant melanoma. Both disease entities display melanin pigment and melanocytic markers, making differentiation between the two difficult. Although clear cell sarcoma cases in the literature have mainly involved deep soft tissues of the extremities, trunk or limb girdles, we report here two cases of primary clear cell sarcoma in unusual sites and describe their clinicopathologic findings.

CASE SUMMARY

The first case involves a 37-year-old female, who presented with jaw pain and a submandibular mass. The second case involves a 33-year-old male, who presented with back pain and a thoracic spine tumor. Both cases showed tumors with diffuse infiltration of neoplastic cells that were positive for melanocytic markers, and in both cases this finding led to an initial diagnosis of metastatic melanoma. However, further analysis by fluorescence in situ hybridization (commonly known as FISH) showed a rearrangement of the EWS RNA binding protein 1 (EWSR1) gene on chromosome 22q12 in both patients, confirming the diagnosis of clear cell sarcoma.

CONCLUSION

Distinction between clear cell sarcoma and malignant melanoma can be made by FISH, particularly in cases of unusual tumor sites.

Keywords: Clear cell sarcoma, Melanoma, Salivary gland, Spine, Fluorescence in situ hybridization, Case report

Core tip: The diagnosis and management of clear cell sarcoma can be a clinical dilemma. Recognition of the clinicopathologic pattern and differentiating it from malignant melanoma can prevent misdiagnosis. This case report not only represents the first reported occurrence of clear cell sarcoma in the submandibular gland in the literature but also identifies another unusual location of involvement, the thoracic spine. It is important to promptly recognize this disease entity because early treatment is necessary to prevent fatal consequences.