Benign Fibrous Histiocytoma of The Right Clavicle



Introduction

Benign Fibrous Histiocytoma (BFH) occurs approximately, 1% of all benign bone tumors and mostly BFH occurs in the long bones where the femur and tibia are most frequently involved. The clavicle is not the common site for all bone tumors and the majority of the clavicular tumor has malignant characteristics.

Case Report

A 20-year-old male presented with chief complaint of mass in the right shoulder. Two years prior to admission, he had a traffic accident and sustained right clavicle fracture. At that time, open reduction internal fixation using plate and screw was carried out. Ten months prior to admission, he complained about a cough but recovered shortly afterward after visiting pulmonologist and received treatment. Four months after, the fracture said to be recovered, therefore he underwent implant removal of the clavicle. He began to realize that there was a painless growing mass on the former site of surgery one month before admission.

Diagnosis

From physical examination, there was a mass with size 8x8x2 cm, regular border and tenderness in his right shoulder without a range of motion limitation. The patient denied having a fever, chronic cough, and weight loss. The post operative scar was good and there was no history of pus or other abnormal condition. There was no past history of illness and there was no family history of malignancy. Laboratory results were uniformly remarkable. Plain radiograph suspected nonunion os clavicula extra. Shoulder CT revealed soft tissue nodule 5.8x5.6x3 cm with clavicle destruction. Plain X-ray of the right clavicle showed that it grew expansively and became 9x6x4 cm in two months based on the physical examination. MRI shoulder extra showed soft tissue tumor in the right shoulder area with the size of 9x6x4 cm. A fine needle aspiration biopsy (FNAB) was performed with a result of benign fibrous histiocytoma. Cytology microscopic showed spreading hypercellular consist of the monomorphic cell with story form pattern, medium size, spindle, ovale, fine chromatine with foamy macrophages, background with eosinophilic amorf mass and diffuse erythrocyte.

Treatment

After we explained the diagnosis, the patient refused any medical procedure.

Discussion

.BFH can arise from a primary process or secondary to another process. It usually presents with mass and pain for days up to several years at the site of the lesions. The histogenesis and classification of fibrohistiocytic lesions that involve bones, are confusing and overlap several entities such as (a) metaphyseal fibrous defect, (b) nonossifying fibroma, (c) fibrous cortical defect, (d) fibrous xanthoma and (e) benign fibrous histiocytoma. Local pain is the main symptom in benign fibrous histiocytoma in contrast to nonossifying fibroma and the X-ray shows an osteolytic lesion with sharply defined sclerotic borders in a typical case of benign fibrous histiocytoma.Histological appearance of BFH of bone is characterized by proliferation of fibroblasts and histiocytes with many multinucleated giant cells. The fibroblasts are arranged in a storiform pattern, the giant cells tend to have fewer nuclei than those found osteoclastoma or giant cell tumor. Most neoplasms of the bone may contain giant cells but the uniform spatial arrangement of osteoclastic giant cells with mononuclear stromal cells is critical in making a diagnosis of giant cell tumor. Lesions with osteoclastic giant cells and spindle cells if present in flat bones also needs to be differentiated from hyperparathyroidism and aneurysmal bone cyst which have other distinctive histological features. BFH may show indistinct borders with an aggressive pattern. It can be locally aggressive and amputation may be necessary to eliminate the tumor after recurrence. Suggested treatments for this tumor are curettage and filling of the defect with bone graft or cement. Recurrence is a risk in treatment and there are reports of recurrence and variable rate of amputation afterward. To rule out the diagnosis of BFH, complete history taking, physical examination, radiograph imaging, and histopathological examination were carried out. BFH may recur after curettage and grew expansively at the local site as seen in a report where five out of eight patients had pain and three patients had a recurrence and two patients had undergone amputation.

Keywords

Benign fibrous histiocytoma, Clavicle, Soft tissue tumor

Author : Happidoc Content Team