S Fiona Bonar

University of Notre Dame, South Bend, Indiana, United States

Are you S Fiona Bonar?

Claim your profile

Publications (18)42.59 Total impact

  • Timothy Shiraev · S Fiona Bonar · Paul Stalley · Suzanne E Anderson ·
    [Show abstract] [Hide abstract]
    ABSTRACT: The retention of foreign bodies after surgery is rare, but carries significant morbidity and mortality as well as financial and legal implications. Such retained items cause a foreign-body reaction, which in the case of cotton-based materials are called gossypibomas. We present the case of an 84-year-old woman with a pseudotumor secondary to a retained dressing gauze roll, presenting 5 months after resection of a gluteal sarcoma, which had raised concerns of local recurrence. We also outline the imaging modalities that may assist in diagnosis of a retained foreign body, and suggest the MRI "row of dots" sign as a useful radiological feature associated with gossypiboma. Awareness of the imaging appearances of retained foreign bodies allows the inclusion of this possibility in differential diagnosis of a mass in patients with a surgical history.
    Skeletal Radiology 03/2013; 42(7). DOI:10.1007/s00256-013-1596-5 · 1.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The histological features of periprosthetic tissues are related to the bioreactivity of particles generated by the prosthesis. This study analyzed synovial-like pseudocapsules collected from 21 patients with alumina ceramic-on-ceramic hip arthroplasties and correlated histological features with wear of the ceramic bearings, duration of implantation and clinical factors such as neck-to-rim impingement. A histopathological classification system was developed for this purpose. The pseudocapsules were viable, with few foreign body type giant cells and occasional lymphocytes. This differs from tissues in polyethylene containing hip arthroplasties which often have extensive foreign body type inflammatory changes or from metal-on-metal hip arthroplasties in which extensive necrosis is common. Soft-tissue inflammation was not associated with failure of the hip arthroplasties, and may be clinically insignificant in alumina-on-alumina total hip arthroplasties.
    The Journal of arthroplasty 03/2013; 28(5). DOI:10.1016/j.arth.2012.10.021 · 2.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A tissue biopsy is usually a critical aspect in guiding appropriate initial management in patients with musculoskeletal tumours. We have previously outlined the role of intra-operative frozen section in both the determination of adequacy of a biopsy and for its diagnostic utility. In this article, the options and techniques for intra-operative pathological evaluation, namely frozen section, fine needle aspiration cytology and touch imprint cytology are reviewed. Frozen section examination may be applicable in the following Sections, including (1) at core biopsy, (2) at surgical margins, (3) at confirming diagnosis prior to definitive treatment or to evaluate tumour spread, and (4) at establishing a diagnosis of a metastasis prior to intramedullary nailing. There are also situations in which frozen section is inappropriate. Pitfalls associated with frozen sections are also highlighted. There are also cost implications, which we have quantified, of performing frozen sections. In our experience that the use of intra-operative pathological evaluation reduces the non-diagnostic rate of bone and soft tissue sarcoma biopsies, eliminates the need for re-biopsy hence alleviating stress, and is a useful addition to the armamentarium in evaluating musculoskeletal tumours.
    Recent results in cancer research. Fortschritte der Krebsforschung. Progr├Ęs dans les recherches sur le cancer 02/2009; 179:11-24. DOI:10.1007/978-3-540-77960-5_2

  • Pathology 01/2009; 40(7):719-22. DOI:10.1080/00313020802436824 · 2.19 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The most common cause of long-term failure of total hip arthroplasty is osteolysis and aseptic loosening secondary to wear debris. Combinations of hard materials such as ceramic-on-ceramic generate smaller volumes of particulate wear debris than traditional combinations such as metal-on-polyethylene. We describe 2 cases where osteolysis arose in hips with third-generation alumina ceramic-on-ceramic couplings. Periarticular tissue in both cases contained titanium wear debris due to impingement of the neck of the titanium femoral component against the rim of the titanium shell and ceramic debris from edge loading wear (stripe wear) of the ceramic. It is not clear whether the titanium debris, the ceramic debris, or both caused the osteolysis. These cases illustrate that the risk of osteolysis persists, even with third-generation alumina ceramics.
    The Journal of arthroplasty 05/2008; 23(8):1240.e13-9. DOI:10.1016/j.arth.2007.10.020 · 2.67 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A case of epithelioid and spindle cell haemangioma of bone occurring in the proximal femur is presented. The tumour had typical microscopic features with a striking lobular pattern comprising spindled and epithelioid areas with admixed inflammatory cells. The case represents only the eighth reported example of this rare tumour, which appears to fit in the spectrum of epithelioid haemangioma. This is the first case to involve the proximal portion of a long bone. A review of the classification and features of similar vascular tumours of bone is presented.
    Skeletal Radiology 07/2007; 36 Suppl 1(S1):S50-7. DOI:10.1007/s00256-006-0135-z · 1.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The most appropriate protocol for the biopsy of musculoskeletal tumours is controversial, with some authors advocating CT-guided core biopsy. At our hospital the initial biopsies of most musculoskeletal tumours has been by operative core biopsy with evaluation by frozen section which determines whether diagnostic tissue has been obtained and, if possible, gives the definitive diagnosis. In order to determine the accuracy and cost-effectiveness of this protocol we have undertaken a retrospective audit of biopsies of musculoskeletal tumours performed over a period of two years. A total of 104 patients had biopsies according to this regime. All gave the diagnosis apart from one minor error which did not alter the management of the patient. There was no requirement for re-biopsy. This protocol was more labour-intensive and 38% more costly than CT-guided core biopsy (AU$1804 vs AU$1308). However, the accuracy and avoidance of the anxiety associated with repeat biopsy outweighed these disadvantages.
    The Bone & Joint Journal 10/2006; 88(9):1207-11. DOI:10.1302/0301-620X.88B9.17680 · 3.31 Impact Factor
  • Rajmohan Murali · Denis Moir · S Fiona Bonar · Leo Pinczewski ·

    International Journal of Surgical Pathology 05/2006; 14(2):146. · 0.95 Impact Factor
  • Rajmohan Murali · Denis Moir · S. Fiona Bonar · Leo Pinczewski ·

    International Journal of Surgical Pathology 04/2006; 14(2):146-146. DOI:10.1177/106689690601400210 · 0.95 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A highly unusual variant of an intraneural ganglion of the common peroneal nerve in a 30-year-old male is presented. There was extrusion of the contents of the cyst into the substance of the nerve, dissecting between the fibres and expanding the nerve in such a way that it mimicked an intraneural tumour clinically, radiologically and histologically. A comprehensive review of the entity is undertaken.
    Skeletal Radiology 04/2006; 35(3):165-71. DOI:10.1007/s00256-005-0031-y · 1.51 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Myopericytoma (MPC) is a recently proposed term to describe a group of tumours that originate from perivascular myoid cells and show a range of histological growth patterns. Only a small number of series describing MPC have been reported. MPC is frequently misdiagnosed as a sarcoma. To document the clinical and histopathological findings of a series of MPCs, to describe the range of growth patterns and morphological spectrum, and to compare MPC with myofibroma (MF). Fourteen patients with features of MPC and/or MF were identified from the archival files of the department of anatomical pathology, Royal Prince Alfred Hospital, Sydney, Australia. There were six female and eight male patients. The mean and median patient ages were 37 and 35.5 years, respectively. The tumours were located in the skin, subcutis, or superficial soft tissues of the distal extremities (13 patients) or the head and neck region (one patient), and showed a spectrum of morphological appearances. They were divided into two groups based upon the predominant growth pattern corresponding to MPC (seven cases) and MF (seven cases). The feature most suggestive of MPC was the presence of a concentric perivascular arrangement of plump spindle shaped cells. The presence of a zonation/biphasic appearance was most characteristic of MF. MPC exhibits a spectrum of growth patterns that overlap with MF. Tumours can be designated as MPC or MF depending on the predominant growth pattern.
    Journal of Clinical Pathology 02/2006; 59(1):67-73. DOI:10.1136/jcp.2005.028704 · 2.92 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Telomeres of tumor cells may be maintained by telomerase or by alternative lengthening of telomeres (ALT). The standard ALT assay requires Southern analysis of high molecular weight genomic DNA. We aimed to establish and validate an ALT assay suitable for archived paraffin-embedded tumors and to use it to examine the prevalence and clinical significance of ALT in various types of tumors that are often telomerase negative. To assay for ALT, we detected ALT-associated promyelocytic leukemia (PML) bodies (APBs) by combined PML immunofluorescence and telomere fluorescence in situ hybridization. APBs are PML nuclear domains containing telomeric DNA and are a known hallmark of ALT in cell lines. The APB assay concurred with the standard ALT assay in 62 of 62 tumors and showed that 35% of 101 soft tissue sarcomas (STS), 47% of 58 osteosarcomas (especially younger patients), 34% of 50 astrocytomas, and 0% of 17 papillary thyroid carcinomas were ALT positive (ALT+). The prevalence of ALT varied greatly among different STS subtypes: malignant fibrous histiocytomas, 77%; leiomyosarcomas, 62%; liposarcomas, 33%; synovial sarcomas, 9%; and rhabdomyosarcomas, 6%. ALT correlated with survival in glioblastoma multiforme and occurred more often in lower-grade astrocytomas, but ALT+ and ALT- sarcomas were equally aggressive in terms of grade and clinical outcome. The APB assay for ALT is suitable for paraffin-embedded tumors. It showed that a substantial proportion of STS, osteosarcomas, and astrocytomas, but not papillary thyroid carcinomas use ALT. APB positivity correlated strongly with survival of patients with astrocytomas.
    Clinical Cancer Research 02/2005; 11(1):217-25. · 8.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Parachordoma is a rare soft tissue tumor that morphologically resembles chordoma of the axial skeleton but occurs in a peripheral site. A recent study reported immunohistochemical differences between chordoma and parachordoma. While both tumors were positive for cytokeratin (CK) 8/18 (as recognized by the antibody Cam5.2), S100 and epithelial membrane antigen (EMA), only the chordoma was positive for CK7, CK20, CK 1/5/10/14 (as recognized by the antibody 34betaE12) and carcinoembryonic antigen (CEA). It has since been suggested that tumors indistinguishable from chordoma that involve the periphery should be termed chordoma periphericum and that these tumors are distinct from parachordoma. In the current study, the clinical, radiological, pathological, immunohistochemical and ultrastructural features of a chordoma-like tumor involving the deep soft tissues of the lower leg of a 69-year-old woman are presented. Microscopically, the tumor had a pseudolobulated growth pattern and consisted of sheets, nests and cords of epithelioid cells, some with a physaliferous appearance, separated by abundant myxoid stroma. The tumor cells were positive for CK 8/18, EMA and S100, showed focal staining for CK7, and were negative for CK20, CK 1/5/10/14 and CEA. On the basis of these results a diagnosis of parachordoma was favored. For comparison, an immunohistochemical analysis of five axial chordomas was also performed. The chordomas showed positivity for CK 8/18 (5 of 5 cases), EMA (5 of 5 cases), S100 (5 of 5 cases), CK 1/5/10/14 (1 of 5 cases) and CK7 (1 of 5 cases). Stains for CK20 and CEA were negative in all five chordomas. The results of the present study suggest that the expression of antigens for CK 1/5/10/14, CK7, CK20 and CEA in chordoma might not be as common as what has been previously reported. The results also suggest that parachordoma might not be easily distinguished immunohistochemically from axial chordoma (and therefore also from so-called chordoma periphericum).
    Pathology International 06/2004; 54(5):364-70. DOI:10.1111/j.1440-1827.2004.01633.x · 1.69 Impact Factor
  • S F Bonar · S McCarthy · P Stalley · J Schatz · J Soper · R Scolyer · I Barrett ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Osteoblastoma-like osteosarcoma is a rare variant of osteosarcoma occurring in this instance in a highly unusual location: the lateral femoral condyle of a 13-year-old girl. The radiological features were non-aggressive and, although slightly unusual, were most suggestive of chondroblastoma.
    Skeletal Radiology 02/2004; 33(1):46-50. DOI:10.1007/s00256-003-0716-z · 1.51 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dendritic fibromyxolipoma (DFML) is an uncommon, recently described, benign soft tissue lesion that shares many clinical and pathological features with myxoid variants of spindle cell lipoma (SCL). As described, DFML is distinguished from SCL by the presence of dendritic cytoplasmic processes, abundant keloidal collagen and a prominent, often plexiform vascular pattern. We describe the first known reported case of an intramuscular DFML that occurred in the right shoulder region of a 73-year-old man. The tumor displayed the typical histopathological features of DFML but also included foci of chondroid metaplasia, a previously unreported finding. This report also discusses the differential diagnosis, particularly distinguishing DFML from SCL and myxoid liposarcoma. In view of the similarities in many clinical and pathological features between SCL and DFML, we speculate that DFML probably represents an unusual variant of myxoid SCL.
    Pathology International 05/2003; 53(4):252-8. DOI:10.1046/j.1320-5463.2003.01464.x · 1.69 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Matrix metalloproteinases (MMPs), together with their tissue inhibitors (TIMPs), are responsible for the controlled degradation of collagen and other matrix substrates in bone and other tissues. This study evaluated the expression of MMPs and TIMPs in bony remodelling in a bilateral sheep mandible model up to 12 months following lengthening by distraction osteogenesis. Sheep mandibles were harvested 3, 6, 9 or 12 months following lengthening by bilateral mandibular distraction (1 mm/day for 20 days). Undistracted sheep mandibles were used as controls. The tissues underwent routine histology and immunohistochemical staining with monoclonal antibodies specific to MMPs 1-3 and TIMP-1, 2. Matrix and cell staining was assessed using a semi-quantitative analysis. Matrix metalloproteinases and their tissue inhibitors (TIMPs) expression levels were marked at 3 months and decreased thereafter becoming similar to undistracted controls by 12 months. The histologic development of mature lamellar cortical bone was similar to undistracted controls by 9 months following distraction. A temporal expression of MMPs and TIMPs was found in distraction osteogenesis. MMPs and TIMPS may, in part, reflect the state of bony remodelling following mandibular lengthening by distraction osteogenesis. Matrix metalloproteinases and TIMP expression were comparable to undistracted controls by 12 months, suggesting that equilibrium had been achieved and that bony relapse is unlikely.
    Journal of Cranio-Maxillofacial Surgery 09/2002; 30(4):208-12. DOI:10.1054/jcms.2002.0289 · 2.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Distraction osteogenesis is a technique used to lengthen the shortened mandible. However, the long term stability of the distracted mandibular bone is not known. The aim of this study was to assess if the sheep mandible relapses following lengthening, and to assess the quality of distracted bone up to 1 year post lengthening. Twenty-four sheep had bilateral external mandibular distractors applied, with three sheep as controls. Titanium marker screws were positioned both proximal and distal to the distraction zone in all sheep. Following a 5 day latency period, the interdental gap was distracted 1 mm/day for 20 days, with a subsequent 20 day consolidation period. Ante-mortem serial X-rays were used to assess for relapse by measuring the distance between the screws. The animals were sacrificed at either 3, 6, 9 or 12 months post-distraction. At post mortem, the distance between the screws was re-measured. The distracted bone was assessed mechanically and histologically. The mean mandibular lengthening obtained was 13.2 mm. There was no relapse of the mandible over 12 months. The distracted bone had attained the strength and stiffness of undistracted bone by 6 months post-distraction (p < 0.05). Histological evaluation revealed significant amounts of lamellar bone by 6 months post-distraction. No relapse occurred for 12 months post distraction lengthening. The bone formed following distraction was stable and of good quality. These findings lend support to the use of distraction osteogenesis in clinical practice.
    Journal of Cranio-Maxillofacial Surgery 11/2000; 28(5):251-7. DOI:10.1054/jcms.2000.0153 · 2.93 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The rabbit model has been used to study the effects of different rates of distraction upon mandibular bone. Bilateral distraction was performed at two different rates anterior to the molar teeth. Both experimental groups were significantly inferior to sham operated controls in terms of bone density (DEXA) and mechanical testing. No difference in new bone formation between the two distraction rates was detected by these modalities. However, histological examination revealed non-union to be more common in the rapidly distracted group. This suggests that attempts to shorten the duration of external fixation in clinical mandibular distraction osteogenesis should be by methods other than more rapid distraction.
    Journal of Cranio-Maxillofacial Surgery 03/1998; 26(1-26):43-49. DOI:10.1016/S1010-5182(98)80034-6 · 2.93 Impact Factor