Collagenous Fibroma With Metaplastic Ossification in the Periocular Region

Key findings from this study

• The study found that metaplastic ossification within collagenous fibroma, although rarely reported, can occur in the periocular region and creates diagnostic ambiguity on imaging studies.
• The authors report that histopathologic examination demonstrating hypocellular collagen-rich stroma with spindle-to-stellate cells and mature lamellar bone islands confirmed the diagnosis in this case.
• The researchers demonstrate that complete local excision achieved curative treatment without recurrence, supporting the benign nature of the lesion despite its radiologic appearance.

Overview

Collagenous fibroma represents a rare benign soft-tissue neoplasm with exceptionally uncommon periocular involvement. Metaplastic ossification within this tumor type has been rarely documented in the literature. The clinical and radiologic presentation can closely resemble more aggressive fibrous or osseous lesions, potentially leading to diagnostic misinterpretation.

Methods and approach

A 49-year-old woman presented with a small, firm mass in the lateral eyebrow region. Magnetic resonance imaging characterized the lesion as well-circumscribed with low signal intensity. Histopathologic examination followed, with tissue sections analyzed for cellular composition and osseous differentiation.

Results

MRI demonstrated a well-circumscribed lesion with low signal intensity, raising concern for fibrous or osseous tumors. Histopathologic evaluation revealed a hypocellular, collagen-rich stroma containing sparse spindle-to-stellate fibroblastic cells. Discrete islands of mature lamellar bone were present within the tumor, establishing the diagnosis of collagenous fibroma with metaplastic ossification. Complete local excision resulted in curative treatment with no recurrence documented during follow-up.

Implications

Recognition of periocular collagenous fibroma with ossification is clinically important despite its benign nature. The radiologic appearance can mimic more aggressive lesions, potentially prompting unnecessary aggressive surgical intervention or misguided clinical management strategies. Inclusion of this entity in the differential diagnosis for periocular firm masses prevents diagnostic confusion and supports conservative surgical planning.

Scope and limitations

This summary is based on the study abstract and available metadata. It does not include a full analysis of the complete paper, supplementary materials, or underlying datasets unless explicitly stated. Findings should be interpreted in the context of the original publication.