Angiomatoid fibrous histiocytoma: a series of seven cases including genetically confirmed aggressive cases and a literature review

Abstract

Background: Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor of intermediate biologic potential. Because of its rarity and nonspecific radiological and diverse pathological findings, AFH is often clinically misdiagnosed. However, few clinical reports have described this tumor. As reported herein, we analyzed the clinical and radiological features and clinical outcomes of AFH.

Methods: We retrospectively reviewed the medical records of seven cases histopathologically diagnosed as AFH. We examined clinical features, MRI findings, histopathological diagnoses, treatments, and outcomes.

Results: These seven cases comprised five male and two female patients with ages ranging from 8 to 50 years old. The primary locations included upper extremities in 2, lower extremities in 4, and the inguinal region in one patient. Of the tumors, 4 occurred in subcutaneous tissues and 3 occurred in deep tissues. No cases were diagnosed as AFH from MRI and needle biopsy results. All cases were diagnosed histopathologically after excision. After treatment, 2 patients (29%) had tumor recurrence and metastasis, one of whom died from disease progression. These 2 aggressive cases involved both EWSR1 and CREB1 gene rearrangements as determined by FISH. The other patients were alive and well without recurrence or metastasis.

Conclusion: AFH is a rare tumor that is difficult to diagnose. Therefore, it tends to be misdiagnosed and to be treated inadequately by referring physicians. Surgeons must therefore be mindful of the presence of AFH, learn about appropriate treatment necessary for this tumor, and conduct careful follow-up because AFH can engender poor outcomes.

Keywords: Angiomatoid fibrous histiocytoma; Diagnosis; Prognosis.

Fig. 1

Histopathological studies of AFH. The photomicrographic images show: (a) peritumoral lymphoplasmacytic cuffing mimicking a lymph node; (b) the growth of spindle cells with storiform distributions; (c) pseudoangiomatous spaces filled with blood, fibrous pseudocapsules, and hemosiderin deposition; and (d) desmin immunoreactivity. (a) Case 3 and (b)-(d) case 6

Fig. 2

A FISH analysis of AFH. The presence of split red and green signals indicates the presence of EWSR1 rearrangement (case 6)

Fig. 3

A 28-year-old woman diagnosed with angiomatoid fibrous histiocytoma (case 1): (a) T1-weighted spin echo, (b) T2-weighted spin echo, and (c) STIR images. A 21 × 23 × 22-mm well-circumscribed, round mass is present in the subcutaneous fat of the posterior right thigh. The lesion is homogeneously hypointense on T1 WI and presents fluid–fluid level (green arrow) and pseudocapsule (yellow arrow) on T2 WI. STIR shows peritumoral edema (red arrows)

Fig. 4

A 36-year-old man diagnosed with angiomatoid fibrous histiocytoma (case 5): (a) T1-weighted spin echo, (b) T2-weighted spin echo, and (c) contrast-enhanced MR images. (d) Non-enhanced and (e) enhanced CT images. A 32 × 36 × 45-mm asymptomatic mass is present in the popliteal lesion of right knee. The lesion is homogeneously isointense on T1 WI and presents with a multilocular area (pink arrow) and pseudocapsule (yellow arrow) on T2 WI. A contrast-enhanced MR image shows intratumoral and peritumoral (white arrow) enhancement. In addition, an enhanced CT image shows variegated enhancement

Fig. 5

A 34-year-old man diagnosed with angiomatoid fibrous histiocytoma (case 6): (a) T1-weighted spin echo, (b, c) T2-weighted spin echo, and (d) contrast-enhanced images. A 163 × 130 × 303-mm painless mass is present in the vastus intermedius of the right thigh. The lesion is heterogeneously iso-hyperintense on T1 WI and presents with a multilocular area, cystic area (blue arrows), fluid–fluid level (green arrows), pseudocapsule, and peritumoral edema (red arrows) on T2 WI. A contrast-enhanced image shows partial gadolinium enhancement (white arrows)