A Picture Gallery of Fibroblastic and Myofibroblastic Tumors with Pathologic Correlation

Purpose or Learning Objective: (1) To show the different types of musculoskeletal fibroblastic and myofibroblastic tumors that belong to the World Health Organization Classification for Soft Tissue Tumors (group II); (2) to classify these tumors according to their characteristics in these subgroups: benign, intermediate locally aggressive, intermediate, rarely metastasizing (low metastatic potential), and malignant; and (3) to describe the radiologic findings of these tumors with pathologic correlation in case examples from our practice.

Methods or Background: All of the patients had a magnetic resonance imaging (MRI) study (Phillips Achieva 1.5 T) with a protocol study of T1-weighted, T2, flow-sensitive dephasing perfusion-weighted imaging, and/or short tau inversion recovery images and postcontrast (gadolinium) fat-saturated T1-weighted images. Most of the patients were studied with both ultrasonography (US) and MRI.

US-guided biopsies were performed in all the patients except for some of the benign tumors (nodular fascitis, palmar/ plantar fibromatosis, and elastofibroma). A 14G core needle biopsy with a spring-loaded biopsy gun was used for all the masses.

Results or Findings: A correct radiologic diagnosis was provided for most of the benign tumors (nodular fascitis, myositis ossificans [except for one], elastofibroma, fibromatosis colli, nasopharyngeal angiofibroma) and for the intermediate /locally aggressive tumors (superficial fibromatosis palmar and plantar, desmoid-type fibromatosis) based on the radiologic findings, age, and location.

However, both the lipofibromas we show were formerly characterized by US and MRI as atypical lipomatous tumors/well-differentiated liposarcomas, and biopsies were indicated to rule out malignancy. The diagnosis of myositis ossificans was not suggested for one of the patients because the radiologic findings in the lesion were early and nonspecific. Early on, the lesion had no calcifications or ossifications, and the patient denied any previous trauma. We could not suggest a correct diagnosis for the solitary fibrous tumor, but it was thought to be an intermediate aggressive or even malignant lesion. The sarcomatous tumors were correctly identified as malignant lesions based on their radiologic findings.

Conclusion: To suggest a correct diagnosis of the fibroblastic and myofibroblastic tumors, thorough knowledge of their radiologic characteristics, typical locations, and age group of presentation are required, so they can be correctly classified into benign, intermediate, and malignant tumors and patients can be provided with the appropriate treatment and follow-up.

Publication History

Article published online:
26 May 2023