Natural evolution of desmoplastic fibroblastoma on magnetic resonance imaging: a case report

<p>Abstract</p> <p>Introduction</p> <p>Desmoplastic fibroblastoma (collagenous fibroma) is a recently described tumor thought to arise predominantly from subcutaneous tissue or skeletal muscle. The natural evolution of this tumor on magnetic resonance imaging has never been described, to the best of our knowledge. We herein report a case of desmoplastic fibroblastoma arising in the thigh and show the longitudinal magnetic resonance imaging findings.</p> <p>Case presentation</p> <p>A 60-year-old Japanese man presented with swelling of the medial side of his right thigh, and he complained of nighttime pain and slight tenderness. Magnetic resonance imaging demonstrated a 4 × 4 cm mass in the right thigh. Open biopsy was performed. The mass was diagnosed histologically as a benign fibrous tumor, and we maintained follow-up without surgical therapy. After one year, magnetic resonance imaging showed an increase in tumor size to 4 × 5 cm, but the histologic findings were the same as those obtained one year earlier. Resection was performed with narrow surgical margins. Pathologic diagnosis was desmoplastic fibroblastoma. Two years after surgery, the patient is free from pain and shows no signs or symptoms of recurrence.</p> <p>Conclusion</p> <p>The natural evolution of desmoplastic fibroblastoma is characterized by no changes in patterns on magnetic resonance imaging despite increasing size. This finding is clinically helpful for distinguishing desmoplastic fibroblastoma with increasing pain from the desmoid tumor.</p

Pseudotumoural soft tissue lesions of the hand and wrist: a pictorial review

Mimickers of soft tissue tumours in the hand and wrist are more frequent than true neoplastic lesions. Pseudotumours belong to a large and heterogeneous group of disorders, varying from normal anatomical variants, cystic lesions, post-traumatic lesions, skin lesions, inflammatory and infectious lesions, non-neoplastic vascular lesions, metabolic disorders (crystal deposition disease and amyloidosis) and miscellaneous disorders. Although the imaging approach to pseudotumoural lesions is often very similar to the approach to “true” soft tissue tumoral counterparts, further management of these lesions is different. Biopsy should be performed only in doubtful cases, when the diagnosis is unclear. Therefore, the radiologist plays a pivotal role in the diagnosis of these lesions. Awareness of the normal anatomy and existence and common imaging presentation of these diseases, in combination with relevant clinical findings (clinical history, age, location and skin changes), enables the radiologist to make the correct diagnosis in most cases, thereby limiting the need for invasive procedures

Pseudotumoural soft tissue lesions of the foot and ankle: a pictorial review

In the foot and ankle region, benign neoplasms and pseudotumoural soft tissue lesions are significantly more frequent than malignant tumours. The pseudotumoural lesions constitute a heterogeneous group, with highly varied aetiology and histopathology. This article reviews the imaging features of the most common pseudotumours of the soft tissues in the foot and ankle. Although the imaging characteristics of several of the lesions discussed are non-specific, combining them with lesion location and clinical features allows the radiologist to suggest a specific diagnosis in most cases

MR imaging of clear cell sarcoma (malignant melanoma of the soft parts): a multicenter correlative MRI-pathology study of 21 cases and literature review.

textabstractObjective. To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). Design and patients. MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. Results. On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. Conclusions. Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well- defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images