The pre-operative differentiation between enchondroma,
low-grade chondrosarcoma and high-grade chondrosarcoma remains a
diagnostic challenge. We reviewed the accuracy and safety of the
radiological grading of cartilaginous tumours through the assessment
of, first, pre-operative radiological and post-operative histological agreement,
and second the rate of recurrence in lesions confirmed as high-grade
on histology. We performed a retrospective review of major long
bone cartilaginous tumours managed by curettage as low grade between
2001 and 2012. A total of 53 patients with a mean age of 47.6 years
(8 to 71) were included. There were 23 men and 30 women. The tumours
involved the femur (n = 20), humerus (n = 18), tibia (n = 9), fibula
(n = 3), radius (n = 2) and ulna (n = 1). Pre-operative diagnoses
resulted from multidisciplinary consensus following radiological
review alone for 35 tumours, or with the addition of pre-operative
image guided needle biopsy for 18. The histologically confirmed diagnosis
was enchondroma for two (3.7%), low-grade chondrosarcoma for 49
(92.6%) and high-grade chondrosarcoma for two (3.7%). Three patients
with a low-grade tumour developed a local recurrence at a mean of 15
months (12 to 17) post-operatively. A single high-grade recurrence
(grade II) was treated with tibial diaphyseal replacement. The overall
recurrence rate was 7.5% at a mean follow-up of 4.7 years (1.2 to
12.3). Cartilaginous tumours identified as low-grade on pre-operative
imaging with or without additional image-guided needle biopsy can
safely be managed as low-grade without pre-operative histological
diagnosis. A few tumours may demonstrate high-grade features histologically,
but the rates of recurrence are not affected. Cite this article:
Local recurrence along the biopsy track is a
known complication of percutaneous needle biopsy of malignant musculoskeletal
tumours. In order to completely excise the track with the tumour
its identification is essential, but this becomes increasingly difficult
over time. In an initial prospective study, 22 of 45 patients (48.8%)
identified over a three-month period, treated by resection of a
musculoskeletal tumour, had an unidentifiable biopsy site at operation,
with identification statistically more difficult after 50 days.
We therefore introduced the practice of marking the biopsy site
with India ink. In all 55 patients undergoing this procedure, the
biopsy track was identified pre-operatively (100%); this difference
was statistically significant. We recommend this technique as a
safe, easy and accurate means of ensuring adequate excision of the
biopsy track.
Cite this article:
The aim of this study was to compare accuracy of an image guided percutaneous core needle biopsy (PCNB), using ultrasound or computed tomography, to PCNB without image guidance in the diagnosis of palpable soft tissue tumors. One hundred forty patients with a suspected soft tissue sarcoma underwent a percutaneous core needle biopsy with or without image guidance. One hundred eleven patients had subsequent surgical excision. The accuracy of guided PCNB and blind PCNB was calculated by comparing the histological results of the needle biopsy to the surgical specimen. The diagnostic accuracy of blind percutaneous core needle biopsy was 78% (36 of 46 biopsies) and significantly lower (p ≤ 0.025) in comparison to image guided percutaneous core needle biopsy which was 95% (62 of 65 biopsies). We suggest that image guidance improves the diagnostic accuracy of PCNB especially for small size deep sited suspected soft tissue tumours.
Of the 27 repeat biopsies a positive histological diagnosis was obtained in 22 patients. The remaining 5 were again non-diagnostic giving a total of 98 patients being treated definitively without a tissue diagnosis. Of these 98 cases, 39 (40%) were treated non-operatively, 37 (38%) had curettage and 22 (22%) underwent wide excision. In the curettage group 33 out of 37 patients had a benign tumour on final histology. Four patients turned out to have intermediate/high grade tumours and subsequently underwent wide excision. In the wide excision group, 17 out of 22 patients had an intermediate/high grade tumour on final histology. Five patients underwent an unnecessarily wide excision of a benign lesion. None of the patients treated non-operatively turned out to have a tumour.
To determine the diagnostic performance of image-guided percutaneous core needle biopsy (CNB) in patients presenting with pathologic fractures of the appendicular skeleton. To determine factors associated with non-diagnostic biopsy and identify cases which should be considered for primary open biopsy. A retrospective audit identified 129 consecutive patients presenting with pathological fractures to a specialist orthopaedic oncology unit over a 9 year period. All patients underwent percutaneous CNB using CT (n=98), fluoroscopy (n=15) or US (n=16) guidance. In all cases MRI or CT was available prior to biopsy to assess the presence and degree of extra-osseous tumour mass. The resulting sample was classified as diagnostic (Group 1) or non-diagnostic (Group 2) on histopathological study. Diagnostic performance was evaluated on the basis of the diagnostic yield and accuracy; these were related to the site of the lesion and presence/absence of extra-osseous mass. Of 129 biopsies, 99 (77%) were classified as Group 1 and 30 (23%) as Group 2. The commonest sites of pathological fracture without associated soft tissue component and resulting in a non-diagnostic biopsy were the proximal femur and proximal humerus. The average cross-sectional diameter of lesions in Group 1 was 5.7 x 5.9cm. Of the 30 lesions comprising Group 2, no soft tissue component was identified on pre-biopsy cross-sectional imaging in 27 lesions (90%) whereas the remaining 3 (10%) showed a smaller extra-osseous soft tissue component compared to the lesions in Group 1. Image-guided percutaneous CNB is a reliable method for obtaining a tissue diagnosis in patients presenting with a pathologic fracture of the appendicular skeleton with high accuracy rate. However, those lesions which are purely intra-osseous or have only very small extra-osseous components are likely to be associated with a non-diagnostic biopsy, and should be considered for a primary open procedure.
Within a study group of 102 consecutive patients diagnosed at a supra-regional bone tumour unit with chondrosarcoma of the femur, tibia or humerus, an association with previously treated breast cancer was noted. There were 58 female patients and 44 male patients. The study group contained six females (10%, mean age 53 years) who had previously been treated for breast cancer, a higher proportion than would be expected. They were referred following identification of a solitary area of increased activity on routine screening with isotope bone scan, presumed to be a solitary bony metastasis. Most (86%) of this breast carcinoma sub-group had developed low-grade bone chondrosarcoma (Trojani grade 0.5-I) and only one case (14%) had developed high-grade chondrosarcoma (Trojani grade II-III). A suspicious long bone lesion on bone scan in a patient with a past medical history of breast cancer must, therefore, not be assumed to be a metastasis without further investigation; the possibility of a chondral lesion should be considered. It is important that patients receive a full multidisciplinary team investigation prior to treatment in order to obtain the correct tissue diagnosis, as the management of these conditions is often different. Our study suggests there may be a relationshipbetween patients previously treated for breast cancer and the development of subsequent chondrosarcoma.
Chondrosarcoma is the second most common primary malignant bone tumour. Distinguishing between grades is not necessarily straightforward and may alter the management of the disease. We evaluated the correlation between the pre-operative needle biopsy and excision biopsy histological grading of chondrosarcoma of the femur, tibia and humerus. A consecutive retrospective series of 100 patients with a histological diagnosis of chondrosarcoma was reviewed. Twenty-one patients were excluded because 20 had only excision biopsy and one had only the pre-operative biopsy on record, thus this series included 79 available cases. In 11 instances, there was a discrepancy in histological grade. Therefore, there was an 86% (68 out of 79) accuracy rate for pre-operative histological grading of chondrosarcoma, based on needle biopsy. However, the accuracy of the diagnostic biopsy to distinguish low-grade from high-grade was 90% (71 out of 79).
The five most common histopathological diagnoses were chondrosarcoma (9%), osteosarcoma (9%), meta-static renal carcinoma (8%), giant-cell tumour (6%), lymphoma (5%). 77% of biopsies yielded a tissue diagnosis. The remaining 23% underwent open biopsy, repeat image-guided needle biopsy or were not further investigated. In the 30 cases (23%) of non-diagnostic biopsies 80% of these lesions had no extra-osseous component to them and the remaining 20% had a very small extra-osseous component.
Elastofibroma dorsi is an uncommon, benign, slow-growing soft-tissue tumour of uncertain aetiology. It classically presents as an ill-defined mass at the inferior pole of the scapula with symptoms which include swelling, discomfort, snapping, stiffness and occasionally pain. We report the symptoms, function and outcome after treatment of 21 elastofibromas in 15 patients. All were diagnosed by MRI and early in the series four also underwent CT-guided biopsy to confirm the diagnosis. In all, 18 tumours were excised and three were observed. After excision, the mean visual analogue score for pain decreased from 4.6 (0 to 10) pre-operatively to 2.4 (0 to 8) post-operatively (p = 0.04). The mean shoulder function, at a mean follow-up of 4.2 years (3 months to 16 years), was 78.1% (30 to 100) using the Stanmore percentage of normal shoulder assessment scoring system. The mean range of forward flexion improved from 135° (70° to 180°) to 166° (100° to 180°) after excision (p = 0.005). In four patients a post-operative haematoma formed; one required evacuation. Three patients developed a post-operative seroma requiring needle aspiration and one developed a superficial infection which was treated with antibiotics. Our findings support previous reports suggesting that a pre-operative tissue diagnosis is not necessary in most cases since the lesion can be confidently diagnosed by MRI, when interpreted in the light of appropriate clinical findings. Surgical excision in symptomatic patients, is helpful. It has been suggested that elastofibroma is caused by a local tissue reaction and is not a true neoplastic process. A strong association has been noted between elastofibroma and repetitive use of the shoulder, which is supported by our findings.
Dedifferentiated chordoma is a rare and aggressive variant of the conventional tumour in which an area undergoes transformation to a high-grade lesion, typically fibrous histiocytoma, fibrosarcoma, and rarely, osteosarcoma or rhabdomyosarcoma. The dedifferentiated component dictates overall survival, with smaller areas of dedifferentiation carrying a more favourable prognosis. Although it is more commonly diagnosed in recurrences and following radiotherapy, there have been a few reports of spontaneous development. We describe four such cases, which were diagnosed
The aim of this study was to compare the accuracy of image guided (ultrasound or CT) percutaneous needle biopsy to percutaneous needle biopsy without image guidance in diagnosis of soft tissue tumours. Eighty-eight consecutive patients with soft tissue lesion who were referred to the soft tissue tumour unit underwent percutaneous needle biopsies of their lesion either with image guidance or without. Sixty-one out of these 88 patients subsequently underwent excision of their lesion and the excised specimen was then subjected to histological examination. The accuracy of image guided percutaneous needle biopsy and percutaneous needle biopsy without image was then calculated by comparing the histological results of the needle biopsy to that of excision biopsy. The diagnosis accuracy of image guided percutaneous needle biopsy was 92% (34 out 37) compared to 79% (22 out of 28) for percutaneous needle biopsy without image. In 3 out of the 28 patients who had percutaneous needle biopsy without image guidance, there was insufficient material obtained from the needle biopsy to allow a histological diagnosis. This was not the case with any of the patients who had image guided percutaneous needle biopsy.
We compared the accuracy of image guided (ultrasound or CT) percutaneous core needle biopsy to percutaneous core needle biopsy without image guidance in diagnosis of soft tissue tumours. 140 patients with soft tissue lesion who were referred to a London bone and soft tissue tumour unit underwent percutaneous core needle biopsies of their lesion either with or without image guidance.111 of these 140 patients subsequently had surgical excision. The accuracy of image guided percutaneous biopsy and percutaneous biopsy without image was then calculated by comparing the histological results of the needle biopsy to that of the resection. The diagnosis accuracy of unguided biopsy was 78% (36 out of 46) compared to 95% (62 out of 65) in image guided. In 6 out of the 46 patients who had unguided biopsy, there was insufficient material obtained from the needle biopsy to allow histological diagnosis. This was not the case with any of the patients who had image guided core needle biopsy. Using image guidance, either USS or CT scan, improves the diagnostic accuracy of percutaneous core needle biopsy and must be considered in management of patients with soft tissue tumours.
Aim: To test the null hypothesis that plain X-rays can provide the same assessment of sacral screw placement as CT. Introduction: Engaging the anterior cortex of the sacrum provides additional strength to fixation and is a goal of surgery. The sacrum with its unique anatomy makes it a difficult bone to assess screw placement radiologically. This study examines the positioning of sacral screws as seen on X-rays and compares the result with spiral CT “gold standard”. Materials and methods: Inclusion criteria: Sacral fixation using Diapason (Stryker) Titanium pedicle screws by one surgeon. Spiral CT, plain AP and lateral X-rays of the sacrum. Exclusion criteria: X-rays with more than three level fixation. There were 66 patients (132 S1 screws). Surgical technique engaged the anterior cortex to enhance fixation. Two independent observers (a musculoskeletal radiologist and spinal fellow) who were blinded to outcome, reported findings in forms with constrained fields. Assessment of plain X-ray and CT was at separate times not less than three weeks apart. Variables noted: Screw position in pedicle, screw tip position, and angle of screw (sagittal on axial CT scans). AP X-ray was divided, for each screw, into nine zones based on the first sacral foramina. The position of the screw tip in the zones was noted. The lateral X-ray was divided into three zones to note the tip of the screw in relation to the cortex. The extent of screw protrusion was measured. X-ray technique: Supine AP centred on fusion and lateral X-ray standing, X-ray source 200 cm from the film. CT: Images acquired on Picker PQ 6000 spiral CT with collimated thickness of 3 mm, pitch 1.25 and reconstructive index of 1.Para-sagittal and coronal reconstructions. Spiral CT was used to note the position of the screw within the pedicle and the relation of the screw tip to the anterior cortex. For screws within the pelvis any structure in close proximity was noted. Results: On CT 10% of the screws had breached the pedicle compared with 2% on the plain X-rays. Anterior cortical perforation had been achieved in 48 out of 132 screws on CT. The sensitivity of the plain X-rays to perforation was 40% with a specificity of 92%. There was an average under estimation of the extent of screw perforation by 4.4 mm (95% confidence ±1 mm). There was a correlation between the position of the screw tip on the AP X-ray and the sensitivity of the lateral X-ray to detect a perforation. The sensitivity ranged from 52% for zone 1 to 15% in zone 8. 15/31 perforations were missed in zone 1, compared with 11/13 in zone 8. For screws penetrating 5 mm or more, in zone 8, 9 out of 10 were missed on lateral X-rays. Eighty-five screws were placed at an angle of less than or equal to 25° to the sagittal; this included 28 out of 34 screws placed in zone 8. The inter-observer variance of screw angle measurement was 1.1° and intra-observer difference 1.7°. Overall 95% confidence of a single measurement was ±3.3°. Conclusion: Plain X-rays and CT do not provide the same assessment of sacral screw placement. This is particularly true for sagitally placed screws with screw tips in zones 7–8.
Ultrasound (US) was used to determine the congruity of the shoulder in 22 children with a deformity of the shoulder secondary to chronic obstetric brachial plexus palsy. There were 11 boys and 11 girls with a mean age of 4.75 years (0.83 to 13.92). The shoulder was scanned in the axial plane using a posterior approach with the arm internally rotated. The humeral head was classified as being either congruent or incongruent. The US appearance was compared with that on clinical examination and related to the intraoperative findings. All 17 shoulders diagnosed as incongruent on US were found to be incongruent at operation, whereas three diagnosed as congruent by US were found to be incongruent at operation. The diagnostic accuracy of US for the identification of shoulder incongruity was 82% when compared with the findings at surgery. US is a valuable, but not infallible tool, for the detection of incongruity of the shoulder.
Osteofibrous dysplasia is a rare condition usually affecting the tibiae and fibulae of males in the first two decades of life. Involvement at the ulna has also been reported in some cases. We describe an extensive, rapidly progressive lesion of the ulna in a three-year-old girl. The progression of the disease accelerated after a local marginal removal, and required extensive resection of the ulna with reconstruction using a fibular autograft. The particular features of this case are the change in the aggressive nature of the condition, which has not been previously reported. We believe that this is only the second recorded case of histologically proven involvement of the ulna.
Needle biopsy is an established technique for the histological diagnosis of bone tumours, usually guided by fluoroscopy or CT. Surface lesions and aggressive tumours which have extended through the cortex are also amenable to imaging with ultrasound (US). We have assessed the diagnostic accuracy of US-guided Trucut needle biopsy in a consecutive series of patients referred to a Bone Tumour Unit with suspected primary bone tumours. Of 144 patients (83 men, 61 women; mean age 34.7 years) referred over a period of two years, 63 were considered suitable for US-guided biopsy. This was based on the presence of a relatively large extraosseous component, seen typically in osteosarcoma and malignant round-cell tumours. The results of needle biopsy were compared with those of surgical biopsy. The diagnostic accuracy was 98.4%, with only a single failed biopsy. Thus, in a selected group of patients, US is a very reliable technique of guidance for percutaneous needle biopsy of bone tumours.
Lateral oblique radiographs are considered important for the identification of spondylolytic lesions, but these projections will give a clear view only when the radiological beam is in the plane of the defect. We studied the variation in orientation of spondylolytic lesions on CT scans of 34 patients with 69 defects. There was a wide variation of angle: only 32% of defects were orientated within 15° of the 45° lateral oblique plane. Lateral oblique radiographs should not be considered as the definitive investigation for spondylolysis. We suggest that CT scans with reverse gantry angle are now more appropriate than oblique radiography for the assessment of spondylolysis. Variation in the angle of the defect may also need consideration when direct repair is being planned.
We have reviewed 13 operations on 11 patients using curettage and polymethylmethacrylate cement for giant-cell tumour of bone (GCT) to assess the value of radiology in the early detection of recurrence. There were four recurrences, the most specific radiological sign on plain radiography was lysis of 5 mm or more at the cement-bone interface. This preceded clinical signs by a mean of four months and was identified at a mean of 3.75 months after operation. There was not always a complete sclerotic margin around the cement, but when it was present, there was never evidence of recurrence. MRI was helpful in assessing cases with evidence of recurrence. Frequent surveillance with plain radiography should continue for one year after operation irrespective of clinical signs of recurrence. When the appearance of the plain radiographs suggests recurrence, MRI should be performed and followed by image-guided needle biopsy.