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MRI diagnosis of plantar fibromatosis—a rare anatomic location
The Foot 13 (2003) 219–222
Case report
MRI diagnosis of plantar fibromatosis—a rare anatomic location S. Sharma a,∗ , A. Sharma b,1 a
Department of Orthopaedics, Victoria Infirmary, South Glasgow University Hospitals, Glasgow G42 9TY, UK b Department of Radiology, Victoria Infirmary, South Glasgow University Hospitals, Glasgow G42 9TY, UK Received 6 January 2003; received in revised form 9 May 2003; accepted 19 May 2003
Abstract Plantar fibromatosis is a relatively uncommon benign, focally invasive fibrous neoplasm. It is most often found to invest the central and medial portions of the plantar fascia. Since the lesion is not encapsulated, clinical margins are often difficult to define. Inadequate excision is the primary cause of recurrence. While it is accepted that the principal use of magnetic resonance imaging (MRI) is showing the extent of a lesion and that it is limited in its ability to provide information regarding likely histology, recognition of the imaging characteristics of plantar fibromatoses can help in the clinical diagnosis. The exception to this role of MRI is when plantar fibromatosis presents itself in an uncharacteristic location. Knowledge of the uncharacteristic locations of these lesions will certainly help radiologists guide the often difficult and protracted therapy of these lesions. The authors present a unique case report of plantar fibromatosis affecting the plantar aspect of the 2nd toe of the foot. © 2003 Elsevier Ltd. All rights reserved. Keywords: Plantar fibromatosis; MRI; Uncharacteristic location
1. Introduction Plantar fibromatosis is a slow growing nodular thickening that occurs within the central band of the plantar fascia. In patients presenting with classic features of plantar fibromatosis, a presumptive diagnosis may be made on clinical grounds alone. In less clear cases, a biopsy may allow confirmation of the diagnosis. However, a biopsy exposes the patient to operative complications. Magnetic resonance imaging (MRI) offers a non-invasive method for confirmation of the clinical diagnosis and can help in preoperative planning [1]. It may also obviate the need for a biopsy [2], which carries with it all the potential risks of a surgical procedure. It is important to diagnose plantar fibromatosis preoperatively as a wide resection is required to prevent recurrence [3]. The paper by Wetzel and Levine [4], point out the difficulty in diagnosing the aggressive variant of plantar fibromatosis as it can be confused with a giant cell tumour. In contrast the benign variant could be diagnosed with ease. While it is accepted that the principal use of MRI is showing the extent of a lesion and that it is limited in ∗ Corresponding author. Present address: 47 Shuna Place, Newton Mearns, Glasgow G77 6TN, UK. Tel.: +44-141-6393820/773-6389740. E-mail address: [email protected] (S. Sharma). 1 Tel.: +44-141-2016000.
0958-2592/$ – see front matter © 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0958-2592(03)00045-2
its ability to provide information regarding likely histology, recognition of the imaging characteristics of plantar fibromatoses and knowledge of the uncharacteristic locations of these lesions will certainly help radiologists guide the often difficult and protracted therapy of these lesions [5].
2. Case report A 41-year-old Asian lady was seen in the orthopaedic clinic complaining of noticing a slowly enlarging swelling of her 2nd toe. The swelling had started 1 year ago and had gradually enlarged to its present size. On examination she had a firm, painless, non-fixed swelling predominantly over the plantar aspect of the proximal phalanx of the 2nd toe but also extending along the medial and lateral borders of the toe. There was no distal neurovascular deficit and she had a full and pain free range of movement of her metatarso-phalangeal (MTP) and proximal inter phalangeal (PIP) joints of the 2nd toe. Axial T1 (Fig. 1) and T2 (Fig. 2) and sagittal T1 (Fig. 3) weighted images (633/20 Repetition time in seconds/echo time milliseconds) of the left forefoot with a surface marker applied to the plantar aspect of the proximal phalanx of the 2nd toe were obtained to help with the diagnosis and preoperative planning. A well defined approximately 2 cm diameter soft tissue mass of
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Fig. 1. Axial T1 image of the foot at the level of the proximal phalanx with a marker over the plantar surface of the 2nd toe showing a soft tissue mass of inhomogenous intermediate signal intensity.
Fig. 2. Axial T2 image of the foot at the level of the proximal phalanx in which the soft tissue mass has a very low signal intensity suggestive of a high collagen content.
Fig. 3. Sagittal T1 image of the foot showing the soft tissue mass of inhomogenous intermediate signal intensity deep to the subcutaneous tissue at the level at the proximal phalanx of the 2nd toe.
S. Sharma, A. Sharma / The Foot 13 (2003) 219–222
221
Fig. 4. Photomicrograph of histology shows a lesion that is predominantly fibrotic.
inhomogeneous intermediate T1 and very low T2 signal was demonstrated over the plantar aspect of the proximal phalanx of the 2nd toe. An intact flexor digitorum tendon was seen to lie eccentrically within the soft tissue mass. There was no evidence of destruction or marrow infiltration of the proximal phalanx. The MTP and PIP joints were normal. A differential diagnosis of a focal nodular synovitis of the tendon sheath of the flexor digitorum longus, giant cell tumour, desmoid tumour and a synovial sarcoma were offered. In the absence of a clear diagnosis a decision was taken to proceed with an excision biopsy of the lesion. Intraoperatively an unencapsulated firm white soft tissue tumour was found deep to the subcutaneous tissue encasing the tendon of the flexor digitorum and displacing it laterally. There was also evidence of erosion of the medial aspect of the proximal pha-
lanx of the 2nd toe. An excision biopsy of the soft tissue tumour, medial neurovascular bundle and flexor tendon along with a curettage of the bony defect of the proximal phalanx was performed. The size of the tissue excised measured 4 cm. Pathological analysis of this tissue (Figs. 4 and 5) revealed spindle-shaped fibrous cells surrounded by abundant collagen suggestive of a plantar fibromatosis. The patient has had no recurrence of the lesion six months following surgery.
3. Discussion and conclusion Plantar fibromatosis is a superficial fibromatosis which occurs between the ages of 30 and 50 years with bilateral
Fig. 5. Magnified photomicrograph of Fig. 4, which shows abundant collagen interspersed with spindle-shaped fibrous cells.
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involvement seen in 20–50% of cases, commonly found in the medial aspect of the plantar aponeurosis as one or multiple firm fixed subcutaneous nodules. Histologically it is composed of spindle-shaped cells separated and surrounded by abundant collagen. It has a strong tendency to local recurrence but does not metastasise. The typical MRI appearance of plantar fibromatosis is a poor defined, infiltrative mass occurring in the deep aponeurosis adjacent to the plantar muscles in the medial aspect of the foot. MRI may show characteristic features of prominent low to intermediate signal intensity and bands of low signal intensity representing highly collagenised tissue and relative hypocellularity in the benign variant, however, the aggressive variant has less collagen and higher cellularity may have a non-specific intermediate to high signal intensity on T2 weighted images. The enhancement with gadolinium contrast material is variable, with marked enhancement seen in approximately 50% of the lesions. While determination of specific anatomic location may help characterise most lesions, this case report highlights the difficulty in diagnosing plantar fibromatosis using a MRI especially in this case where the lesion extended into an uncharacteristic location such as the forefoot. Moreover, the diagnostic capability of MRI can be affected by the aggressiveness of the lesion. While the benign variant of plantar fibromatosis can be accurately diagnosed [6]; the aggressive variant may be confused with a giant cell tumour.
This case report emphasises that while MRI delineates the extent of the lesion, it cannot always replace a biopsy in the diagnosis and preoperative planning of plantar fibromatosis. Acknowledgements The authors would like to acknowledge Dr. McLellan, Consultant Pathologist, for his help with the histopathological images in this paper. References [1] Pasternack WA, Davison GA. Plantar fibromatosis: staging by magnetic resonance imaging. J Foot Ankle Surg 1993;32:390–6. [2] Watson-Ramirez L, Rasmussen SE, Warschaw KE, Mulloy JP, Elston DM. Plantar fibromatosis: use of magnetic resonance imaging in diagnosis. Cutis 2001;68(3):219–22. [3] Sammarco GJ, Mangone PG. Classification and treatment of plantar fibromatosis. Foot Ankle Int 2000;21(7):563–9. [4] Wetzel LH, Levine E. Soft-tissue tumors of the foot: value of MR imaging for specific diagnosis. Am J Roentgenol 1990;155(5):1025– 30. [5] Robbin MR, Murphey MD, ThomasTemple H, Kransdorf MJ, Choi JJ. Imaging of musculoskeletal fibromatosis. Radiographics 2001;21:585– 600. [6] Morrison WB, Schweitzer ME, Wapner KL, Lackman RD. Plantar fibromatosis: a benign aggressive neoplasm with a characteristic appearance on MR images. Radiology 1993;3:841–5.
Case report
MRI diagnosis of plantar fibromatosis—a rare anatomic location S. Sharma a,∗ , A. Sharma b,1 a
Department of Orthopaedics, Victoria Infirmary, South Glasgow University Hospitals, Glasgow G42 9TY, UK b Department of Radiology, Victoria Infirmary, South Glasgow University Hospitals, Glasgow G42 9TY, UK Received 6 January 2003; received in revised form 9 May 2003; accepted 19 May 2003
Abstract Plantar fibromatosis is a relatively uncommon benign, focally invasive fibrous neoplasm. It is most often found to invest the central and medial portions of the plantar fascia. Since the lesion is not encapsulated, clinical margins are often difficult to define. Inadequate excision is the primary cause of recurrence. While it is accepted that the principal use of magnetic resonance imaging (MRI) is showing the extent of a lesion and that it is limited in its ability to provide information regarding likely histology, recognition of the imaging characteristics of plantar fibromatoses can help in the clinical diagnosis. The exception to this role of MRI is when plantar fibromatosis presents itself in an uncharacteristic location. Knowledge of the uncharacteristic locations of these lesions will certainly help radiologists guide the often difficult and protracted therapy of these lesions. The authors present a unique case report of plantar fibromatosis affecting the plantar aspect of the 2nd toe of the foot. © 2003 Elsevier Ltd. All rights reserved. Keywords: Plantar fibromatosis; MRI; Uncharacteristic location
1. Introduction Plantar fibromatosis is a slow growing nodular thickening that occurs within the central band of the plantar fascia. In patients presenting with classic features of plantar fibromatosis, a presumptive diagnosis may be made on clinical grounds alone. In less clear cases, a biopsy may allow confirmation of the diagnosis. However, a biopsy exposes the patient to operative complications. Magnetic resonance imaging (MRI) offers a non-invasive method for confirmation of the clinical diagnosis and can help in preoperative planning [1]. It may also obviate the need for a biopsy [2], which carries with it all the potential risks of a surgical procedure. It is important to diagnose plantar fibromatosis preoperatively as a wide resection is required to prevent recurrence [3]. The paper by Wetzel and Levine [4], point out the difficulty in diagnosing the aggressive variant of plantar fibromatosis as it can be confused with a giant cell tumour. In contrast the benign variant could be diagnosed with ease. While it is accepted that the principal use of MRI is showing the extent of a lesion and that it is limited in ∗ Corresponding author. Present address: 47 Shuna Place, Newton Mearns, Glasgow G77 6TN, UK. Tel.: +44-141-6393820/773-6389740. E-mail address: [email protected] (S. Sharma). 1 Tel.: +44-141-2016000.
0958-2592/$ – see front matter © 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0958-2592(03)00045-2
its ability to provide information regarding likely histology, recognition of the imaging characteristics of plantar fibromatoses and knowledge of the uncharacteristic locations of these lesions will certainly help radiologists guide the often difficult and protracted therapy of these lesions [5].
2. Case report A 41-year-old Asian lady was seen in the orthopaedic clinic complaining of noticing a slowly enlarging swelling of her 2nd toe. The swelling had started 1 year ago and had gradually enlarged to its present size. On examination she had a firm, painless, non-fixed swelling predominantly over the plantar aspect of the proximal phalanx of the 2nd toe but also extending along the medial and lateral borders of the toe. There was no distal neurovascular deficit and she had a full and pain free range of movement of her metatarso-phalangeal (MTP) and proximal inter phalangeal (PIP) joints of the 2nd toe. Axial T1 (Fig. 1) and T2 (Fig. 2) and sagittal T1 (Fig. 3) weighted images (633/20 Repetition time in seconds/echo time milliseconds) of the left forefoot with a surface marker applied to the plantar aspect of the proximal phalanx of the 2nd toe were obtained to help with the diagnosis and preoperative planning. A well defined approximately 2 cm diameter soft tissue mass of
220
S. Sharma, A. Sharma / The Foot 13 (2003) 219–222
Fig. 1. Axial T1 image of the foot at the level of the proximal phalanx with a marker over the plantar surface of the 2nd toe showing a soft tissue mass of inhomogenous intermediate signal intensity.
Fig. 2. Axial T2 image of the foot at the level of the proximal phalanx in which the soft tissue mass has a very low signal intensity suggestive of a high collagen content.
Fig. 3. Sagittal T1 image of the foot showing the soft tissue mass of inhomogenous intermediate signal intensity deep to the subcutaneous tissue at the level at the proximal phalanx of the 2nd toe.
S. Sharma, A. Sharma / The Foot 13 (2003) 219–222
221
Fig. 4. Photomicrograph of histology shows a lesion that is predominantly fibrotic.
inhomogeneous intermediate T1 and very low T2 signal was demonstrated over the plantar aspect of the proximal phalanx of the 2nd toe. An intact flexor digitorum tendon was seen to lie eccentrically within the soft tissue mass. There was no evidence of destruction or marrow infiltration of the proximal phalanx. The MTP and PIP joints were normal. A differential diagnosis of a focal nodular synovitis of the tendon sheath of the flexor digitorum longus, giant cell tumour, desmoid tumour and a synovial sarcoma were offered. In the absence of a clear diagnosis a decision was taken to proceed with an excision biopsy of the lesion. Intraoperatively an unencapsulated firm white soft tissue tumour was found deep to the subcutaneous tissue encasing the tendon of the flexor digitorum and displacing it laterally. There was also evidence of erosion of the medial aspect of the proximal pha-
lanx of the 2nd toe. An excision biopsy of the soft tissue tumour, medial neurovascular bundle and flexor tendon along with a curettage of the bony defect of the proximal phalanx was performed. The size of the tissue excised measured 4 cm. Pathological analysis of this tissue (Figs. 4 and 5) revealed spindle-shaped fibrous cells surrounded by abundant collagen suggestive of a plantar fibromatosis. The patient has had no recurrence of the lesion six months following surgery.
3. Discussion and conclusion Plantar fibromatosis is a superficial fibromatosis which occurs between the ages of 30 and 50 years with bilateral
Fig. 5. Magnified photomicrograph of Fig. 4, which shows abundant collagen interspersed with spindle-shaped fibrous cells.
222
S. Sharma, A. Sharma / The Foot 13 (2003) 219–222
involvement seen in 20–50% of cases, commonly found in the medial aspect of the plantar aponeurosis as one or multiple firm fixed subcutaneous nodules. Histologically it is composed of spindle-shaped cells separated and surrounded by abundant collagen. It has a strong tendency to local recurrence but does not metastasise. The typical MRI appearance of plantar fibromatosis is a poor defined, infiltrative mass occurring in the deep aponeurosis adjacent to the plantar muscles in the medial aspect of the foot. MRI may show characteristic features of prominent low to intermediate signal intensity and bands of low signal intensity representing highly collagenised tissue and relative hypocellularity in the benign variant, however, the aggressive variant has less collagen and higher cellularity may have a non-specific intermediate to high signal intensity on T2 weighted images. The enhancement with gadolinium contrast material is variable, with marked enhancement seen in approximately 50% of the lesions. While determination of specific anatomic location may help characterise most lesions, this case report highlights the difficulty in diagnosing plantar fibromatosis using a MRI especially in this case where the lesion extended into an uncharacteristic location such as the forefoot. Moreover, the diagnostic capability of MRI can be affected by the aggressiveness of the lesion. While the benign variant of plantar fibromatosis can be accurately diagnosed [6]; the aggressive variant may be confused with a giant cell tumour.
This case report emphasises that while MRI delineates the extent of the lesion, it cannot always replace a biopsy in the diagnosis and preoperative planning of plantar fibromatosis. Acknowledgements The authors would like to acknowledge Dr. McLellan, Consultant Pathologist, for his help with the histopathological images in this paper. References [1] Pasternack WA, Davison GA. Plantar fibromatosis: staging by magnetic resonance imaging. J Foot Ankle Surg 1993;32:390–6. [2] Watson-Ramirez L, Rasmussen SE, Warschaw KE, Mulloy JP, Elston DM. Plantar fibromatosis: use of magnetic resonance imaging in diagnosis. Cutis 2001;68(3):219–22. [3] Sammarco GJ, Mangone PG. Classification and treatment of plantar fibromatosis. Foot Ankle Int 2000;21(7):563–9. [4] Wetzel LH, Levine E. Soft-tissue tumors of the foot: value of MR imaging for specific diagnosis. Am J Roentgenol 1990;155(5):1025– 30. [5] Robbin MR, Murphey MD, ThomasTemple H, Kransdorf MJ, Choi JJ. Imaging of musculoskeletal fibromatosis. Radiographics 2001;21:585– 600. [6] Morrison WB, Schweitzer ME, Wapner KL, Lackman RD. Plantar fibromatosis: a benign aggressive neoplasm with a characteristic appearance on MR images. Radiology 1993;3:841–5.