Myositis ossificans mimicking sarcoma: a not so rare bioptic diagnostic pitfall

Abstract

Background: Myositis ossificans (MO) is a heterotopic bone formation in soft tissues, usually caused by traumas or neuropathies. Although the aetiology remains unclear, MO is supposed to be an osteoblast metaplasia with a benign and self-limiting course. Remarkably, at onset MO can be clinically, radiologically and histologically indistinguishable to soft tissue malignancies, especially in cases lacking a history of trauma, leading to misdiagnoses and improper treatments. Case presentation: A 13-year-old male was referred to the Oncology Department because of a previous diagnosis of osteogenic sarcoma of his left thigh. The diagnosis was made upon a history of isolated thigh pain in the absence of traumas, the evidence of a contrast-enhanced soft tissue mass on magnetic resonance imaging and the histological findings of atypical nuclei and mitotic figures. The lesion was eventually radiologically unchanged after five cycles of chemotherapy; thus, the child was referred for radical surgery. At admission, endorsing the child wellappearance, together with the evidence of a reduced calcified lesion on a further magnetic resonance, a clinical suspicion of myositis ossificans was raised. Hence, the excisional biopsy confirmed the pathognomonic zonal pattern of myositis ossificans. Conclusions: This case highlights some frequent diagnostic pitfalls facing myositis ossificans. A lacking history of traumas, along with a too early radiological and histological evaluation can lead to a misdiagnosis of soft tissue malignancies. Even in the absence of a clear history of trauma, a painful soft tissue swelling with a benign clinical course should raise the suspicion of myositis ossificans.

Myositis ossificans mimicking bone surface osteosarcoma: case report with literature review

“…Early misdiagnosis of myositis ossificans for other malignant bone surface lesions can be a diagnostic pitfall and challenge for clinicians, as highlighted by several case reports and series published in the literature (Table 1) (13)(14)(15)(16)(17)(18). While the radiographic appearance of bone formation at the periphery of the lesion may be suggestive of myositis ossificans, a definitive diagnosis of surface myositis ossificans requires pathologic examination of the tissue (14,19,20).…”

Sağlık Bilimlerinde Akademik Analiz ve Tartışmalar

“…Osteoid matriks nekroz ve dejenerasyon sonucunda gelişen kalsifikasyonlar ve patalojik kırık sonucu gelişen kallus dokusuyla karıştırılmamalıdır. Myozitis ossifikansta ortaya çıkan matür ossifikasyonda en yüksek dansite periferde izlenirken parosteal osteosarkom gibi yüzey tümörlerinde en yüksek dansite merkezde olup perifere doğru yoğunluk azalmış olarak izlenmektedir (Cortellazzo Wiel, Trevisan, Murru, Rabusin, & Barbi, 2020). Kıkırdak üreten, enkondrom, kondroblastom, kondrosarkom ve kondromiksoid fibrom gibi lezyonlarda, lezyon santralinde nokta, virgül, halka ve patlamış mısır şeklinde matriks kalsifikasyonları izlenir (Vasudeva, Shyam Kumar, & Ayyappa Naidu, 2020).…”

Diagnostic and Imaging Approaches to Chest Wall Lesions

“…Early MO can enhance and be mistaken for sarcoma; in this scenario, follow-up imaging can be performed for a more definitive diagnosis (27). It should be noted that it is preferable not to perform biopsy of these lesions, as they have been reported to be mistaken for malignancy at histopathologic analysis (28,29).…”