Juxta-articular extraskeletal myxoid chondrosarcoma mistaken for a benign cyst presenting with multiple lung metastases

Dmitriy Starostin; Ibrahim Azam; Michael Paddock; Malee S Fernando; Scott Evans MBChB; Nikhil Kotnis

doi:10.1016/j.radcr.2023.10.075

Juxta-articular extraskeletal myxoid chondrosarcoma mistaken for a benign cyst presenting with multiple lung metastases

Radiol Case Rep. 2023 Nov 27;19(2):684-690. doi: 10.1016/j.radcr.2023.10.075. eCollection 2024 Feb.

Authors

Dmitriy Starostin¹, Ibrahim Azam², Michael Paddock^{3

4

5

6}, Malee S Fernando⁷, Scott Evans MBChB^{8

9}, Nikhil Kotnis¹⁰

Affiliations

¹ Clinical Radiology Department, Sheffield Teaching Hospitals NHS Trust, Sheffield, UK.
² Department of Radiology, Stoke Mandeville Hospital, Buckinghamshire Healthcare NHS Trust, Buckinghamshire, UK.
³ Medical Imaging Department, Perth Children's Hospital, Perth, Western Australia, Australia.
⁴ Division of Pediatrics, University of Western Australia, Perth, Western Australia, Australia.
⁵ School of Medicine, The University of Notre Dame Australia, Perth, Western Australia, Australia.
⁶ Division of Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK.
⁷ Sheffield Teaching Hospitals NHS Trust, Sheffield, UK.
⁸ The Royal Orthopedic Hospital, Birmingham, UK.
⁹ University of Birmingham, Birmingham, UK.
¹⁰ MSK Radiology Department, Sheffield Teaching Hospitals NHS Trust, Sheffield, UK.

Abstract

Extraskeletal myxoid chondrosarcoma (EMC) is a malignant cartilage neoplasm usually encountered in the proximal extremities. We report the case of a 58-year-old male who presented initially with a 3-month history of cough. Initial staging demonstrated a right upper lobe mass with bilateral pulmonary nodules and moderate tracer uptake in the right lung mass and right groin on positron emission tomography imaging. Endobronchial ultrasound biopsy confirmed a histological diagnosis of EMC for which the patient underwent right upper lobe wedge resection. Pelvic MRI revealed a peripherally enhancing juxta-articular lesion within the region of the right obturator externus bursa, which was thought initially to represent either a ganglion or paralabral cyst. However, ultrasound-guided biopsy yielded identical histology to the resected lung mass leading to the diagnosis of primary EMC in the right groin with pulmonary metastases. The patient underwent surgical excision of the right groin mass with no local recurrence on the surveillance computed tomography at 5, 12, and 18 months but eventual disease recurrence in the right groin and further progression of the pulmonary metastases at 29 months. We emphasize that the contrast enhancement pattern of EMC can mimic a benign cystic lesion, in particular, when in a juxta-articular location, which has the potential to mislead radiologists and delay diagnosis and definitive treatment.

Keywords: EMC; Extraskeletal myxoid chondrosarcoma; Paralabral cyst; Sarcoma.

Publication types

Case Reports