ClinicalRadiology(1992)
46, 359-360
Case Report: Desmoplastic Fibroma of the Sternum R . O . I. O B A R O
Department of Radiology, Royal Victoria Infirmary, Newcastle upon Tyne Desmoplastic fibroma of bone is very rare. This is only the second case reported in the sternum and the first reported with CT findings. O b a r o R . O . I . ( 1 9 9 2 ) . Clinical Radiology 4 6 , 359 360. Case Report:
CASE
Desmoplastic
Fibroma
of the Sternum
REPORT
A 36-year-old Asian supermarket owner presented with a history of upper abdominal pain and acid regurgitation for 1 year. Symptoms were thought to be due to gastro-oesophageat reflux and he was treated with antacids and cimetidine with limited success. The symptoms persisted with some tenderness in the epigastrium. Chest X-ray and lateral sternum views were obtained which showed a slightly expanding lesion that breached the cortex in the lower part of the sternum (Fig. 1). A differential diagnosis of renal or thyroid secondaries, aneurysmai bone cyst, tuberculosis and lymphoma was made. Abdominal and thyroid ultrasound examinations and ESR were normal. There was slight elevation of serum alkaline phosphatase and gamma glutamyl transaminase. CT examination of the sternum showed an expansile, destructive lesion with slight soft tissue swelling (Fig. 2).
Fig. 2 - CT scan of the sternum confirming the destructive nature of the lesion and slight soft tissue swelling.
Fig. 3 The photograph shows the proliferating plump fibroblasts in the centre of the lesion within the bone in a dense collagenous background. (Courtesy of Dr C.M. Corbishley, Department of Pathology, St George's Hospital.) The lesion was excised through a bilateral submammary incision and a Martesa mesh inserted into the resulting sternal defect. Histological features showed loose bundles of fibrous tissue that were composed of slim spindle-shaped fibroblasts with variable amounts of bands of collagen fibres. No mitoses were identified. The appearances were consistent with a desmosplastic fibroma (Fig. 3). Follow-up 2 years later showed no recurrence. Fig. 1 - P l a i n film of the sternum showing an expansile, lytic lesion in the lower sternum. Only minimal soft tissue swelling is present. Correspondence to: Dr R. O. I. Obaro, Senior Registrar, Department of Radiology, Royal Victoria Infirmary, Newcastle upon Tyne NEI 4LP.
DISCUSSION Desmoplastic fibromas of bone are rare accounting for 0 . 0 6 % o f all b o n e t u m o u r s [1]. T h e t e r m w a s f i r s t
360
CLINICAL RADIOLOGY
introduced by Jaffe in 1958 (cited by Graudal [4]). The histology shows monotonous fibroblasts embedded in a dense collagenous stroma with elongated nuclei and absent mitoses [1]. It has been classifed as an 'aggressive benign lesion' [2]. The lesion may present with pain and swelling [1], tenderness [3] or pathological fracture [1]. Symptoms are often vague and of long duration. The present case had only epigastric symptoms, none of which could reliably relate to the presenting lesion. Lesions have been described most commonly in the mandible, long bones and pelvis [1,4,5]. On only one previous occasion has it been recorded in the sternum [6]. The radiological appearances are easily confused with other benign or malignant bone lesions [7]. When present in long bones such as the femur or tibia, they are usually located centrally in the metaphysis. They may show expansion, destruction, lysis or a bubbly honey-combed appearance. Periosteal reactions are usually absent [8,9]. Radionuclide seintigraphy may show raised uptake at the site of the lesion [4]. An associated soft tissue mass may be demonstrated. The present lesion was expansile and lytic with slight soft tissue swelling. The previous sternal lesion mentioned by Waddell and Gerner [6] was not described in their paper. The major radiological differential diagnoses are low grade fibrosarcoma, fibrous dysplasia, brown tumour, dentigerous cyst, chondromyxoid fibroma and secondary deposits from thyroid or kidney. The most common sternal turnouts are chondrosarcoma, myeloma and reticulum cell sarcomas [10]. It is hardly surprising that a desmoplastic fibroma was not initially considered during this patient's clinical work up. Management consists of wide surgical excision with bone grafting or prosthetic replacements in appropriate regions. Patients treated simply by currettage have a high rate of recurrence [1] which may be related to the cellularity of the lesion [7]. A few cases, including the only other reported sternal tumour, responded to Indomethacin with or without ascorbic acid [6], although the exact mechanism for this is unknown. Only one reported case of desmoplastic fibroma has responded to radiotherapy [10].
So far, the present case has shown no recurrence 2 years after local excision.
CONCLUSION A case of desmoplastic fibroma of the sternum has been presented. The difficulties in diagnosis, differential diagnoses" and management have been discussed. Acknowledgements. I wish to thank Mr N. Wright, St George's Hospital, Tooting, for allowing me access to the patient's notes. My thanks also go to Dr A. G. Wilson, St George's Hospital, Tooting, London, and Dr J. P. Owen, University of Newcastle upon Tyne, for reading the manuscript and Mrs J. T. Stoddart for typing it.
REFERENCES 1 Gebhardt MC, Campbell CJ, Schnller AL, Mankin HJ. Desmoplastic fibroma of bone. A report of eighty-eight cases and review of the literature. Journal of Bone and Joint Surgery 1985;67:732 747. 2 Hadjipaulou A, Lander PH, Begin LR, Eibel P. Desmoplastic fibroma of a metatarsal. Case report. Journal of Bone and Joint Surgery 1986;68:459 461. 3 Enneking WF. Staging of musculoskeletal neoplasms. Skeletal Radiology 1985;13:183-194. 4 Graudal N. Desmoplastic fibroma of bone. Case report and literature review. Acta Orthopaedic Scandinavia 1984;55:215 219. 5 Beskin JL, Haddard RJ. Desmoplastic fibroma of the first metatarsal. A case report. Clinical Orthopaedics and Related Research 1985; 195:299-303. 6 Waddell WR, Gerner RE. Indomethacin and ascorbate inhibit desmoit tumours. Journal of Surgical Oncology 1980; 15:85-90. 7 Rabham WN, Rosai J. Desmoplastic fibroma. Report of ten cases and review of the literature. Journal of Bone and Joint Surgery 1968;50:487-502. 8 Thirupathi RG, Voletin JC, Wadwa R, Baltah S. Desmoplastic fibroma of the ulna. A case report. Clinical Orthopaedics and Related Research 1983;179:231-238. 9 Schultz E, Herman G, Gerald AL, Shih H. Case report 380. Skeletal Radiology 1986; 15:560-564. 10 Omell HG, Anderson SL, Bramson RT. Radiologie Clinics of North America 1973;XI:197-214. 11 Dahlin DC, Hoover N. Desmoplastic fibroma of bone. Report of two cases. Journal of the American Medical Association 1964; 188:685-687.
46, 359-360
Case Report: Desmoplastic Fibroma of the Sternum R . O . I. O B A R O
Department of Radiology, Royal Victoria Infirmary, Newcastle upon Tyne Desmoplastic fibroma of bone is very rare. This is only the second case reported in the sternum and the first reported with CT findings. O b a r o R . O . I . ( 1 9 9 2 ) . Clinical Radiology 4 6 , 359 360. Case Report:
CASE
Desmoplastic
Fibroma
of the Sternum
REPORT
A 36-year-old Asian supermarket owner presented with a history of upper abdominal pain and acid regurgitation for 1 year. Symptoms were thought to be due to gastro-oesophageat reflux and he was treated with antacids and cimetidine with limited success. The symptoms persisted with some tenderness in the epigastrium. Chest X-ray and lateral sternum views were obtained which showed a slightly expanding lesion that breached the cortex in the lower part of the sternum (Fig. 1). A differential diagnosis of renal or thyroid secondaries, aneurysmai bone cyst, tuberculosis and lymphoma was made. Abdominal and thyroid ultrasound examinations and ESR were normal. There was slight elevation of serum alkaline phosphatase and gamma glutamyl transaminase. CT examination of the sternum showed an expansile, destructive lesion with slight soft tissue swelling (Fig. 2).
Fig. 2 - CT scan of the sternum confirming the destructive nature of the lesion and slight soft tissue swelling.
Fig. 3 The photograph shows the proliferating plump fibroblasts in the centre of the lesion within the bone in a dense collagenous background. (Courtesy of Dr C.M. Corbishley, Department of Pathology, St George's Hospital.) The lesion was excised through a bilateral submammary incision and a Martesa mesh inserted into the resulting sternal defect. Histological features showed loose bundles of fibrous tissue that were composed of slim spindle-shaped fibroblasts with variable amounts of bands of collagen fibres. No mitoses were identified. The appearances were consistent with a desmosplastic fibroma (Fig. 3). Follow-up 2 years later showed no recurrence. Fig. 1 - P l a i n film of the sternum showing an expansile, lytic lesion in the lower sternum. Only minimal soft tissue swelling is present. Correspondence to: Dr R. O. I. Obaro, Senior Registrar, Department of Radiology, Royal Victoria Infirmary, Newcastle upon Tyne NEI 4LP.
DISCUSSION Desmoplastic fibromas of bone are rare accounting for 0 . 0 6 % o f all b o n e t u m o u r s [1]. T h e t e r m w a s f i r s t
360
CLINICAL RADIOLOGY
introduced by Jaffe in 1958 (cited by Graudal [4]). The histology shows monotonous fibroblasts embedded in a dense collagenous stroma with elongated nuclei and absent mitoses [1]. It has been classifed as an 'aggressive benign lesion' [2]. The lesion may present with pain and swelling [1], tenderness [3] or pathological fracture [1]. Symptoms are often vague and of long duration. The present case had only epigastric symptoms, none of which could reliably relate to the presenting lesion. Lesions have been described most commonly in the mandible, long bones and pelvis [1,4,5]. On only one previous occasion has it been recorded in the sternum [6]. The radiological appearances are easily confused with other benign or malignant bone lesions [7]. When present in long bones such as the femur or tibia, they are usually located centrally in the metaphysis. They may show expansion, destruction, lysis or a bubbly honey-combed appearance. Periosteal reactions are usually absent [8,9]. Radionuclide seintigraphy may show raised uptake at the site of the lesion [4]. An associated soft tissue mass may be demonstrated. The present lesion was expansile and lytic with slight soft tissue swelling. The previous sternal lesion mentioned by Waddell and Gerner [6] was not described in their paper. The major radiological differential diagnoses are low grade fibrosarcoma, fibrous dysplasia, brown tumour, dentigerous cyst, chondromyxoid fibroma and secondary deposits from thyroid or kidney. The most common sternal turnouts are chondrosarcoma, myeloma and reticulum cell sarcomas [10]. It is hardly surprising that a desmoplastic fibroma was not initially considered during this patient's clinical work up. Management consists of wide surgical excision with bone grafting or prosthetic replacements in appropriate regions. Patients treated simply by currettage have a high rate of recurrence [1] which may be related to the cellularity of the lesion [7]. A few cases, including the only other reported sternal tumour, responded to Indomethacin with or without ascorbic acid [6], although the exact mechanism for this is unknown. Only one reported case of desmoplastic fibroma has responded to radiotherapy [10].
So far, the present case has shown no recurrence 2 years after local excision.
CONCLUSION A case of desmoplastic fibroma of the sternum has been presented. The difficulties in diagnosis, differential diagnoses" and management have been discussed. Acknowledgements. I wish to thank Mr N. Wright, St George's Hospital, Tooting, for allowing me access to the patient's notes. My thanks also go to Dr A. G. Wilson, St George's Hospital, Tooting, London, and Dr J. P. Owen, University of Newcastle upon Tyne, for reading the manuscript and Mrs J. T. Stoddart for typing it.
REFERENCES 1 Gebhardt MC, Campbell CJ, Schnller AL, Mankin HJ. Desmoplastic fibroma of bone. A report of eighty-eight cases and review of the literature. Journal of Bone and Joint Surgery 1985;67:732 747. 2 Hadjipaulou A, Lander PH, Begin LR, Eibel P. Desmoplastic fibroma of a metatarsal. Case report. Journal of Bone and Joint Surgery 1986;68:459 461. 3 Enneking WF. Staging of musculoskeletal neoplasms. Skeletal Radiology 1985;13:183-194. 4 Graudal N. Desmoplastic fibroma of bone. Case report and literature review. Acta Orthopaedic Scandinavia 1984;55:215 219. 5 Beskin JL, Haddard RJ. Desmoplastic fibroma of the first metatarsal. A case report. Clinical Orthopaedics and Related Research 1985; 195:299-303. 6 Waddell WR, Gerner RE. Indomethacin and ascorbate inhibit desmoit tumours. Journal of Surgical Oncology 1980; 15:85-90. 7 Rabham WN, Rosai J. Desmoplastic fibroma. Report of ten cases and review of the literature. Journal of Bone and Joint Surgery 1968;50:487-502. 8 Thirupathi RG, Voletin JC, Wadwa R, Baltah S. Desmoplastic fibroma of the ulna. A case report. Clinical Orthopaedics and Related Research 1983;179:231-238. 9 Schultz E, Herman G, Gerald AL, Shih H. Case report 380. Skeletal Radiology 1986; 15:560-564. 10 Omell HG, Anderson SL, Bramson RT. Radiologie Clinics of North America 1973;XI:197-214. 11 Dahlin DC, Hoover N. Desmoplastic fibroma of bone. Report of two cases. Journal of the American Medical Association 1964; 188:685-687.
