Pseudotumor In Patient Research Articles

Prevalence of likely retro-odontoid pseudotumor in patients receiving dental CBCT examinations

ObjectivesWe calculated the prevalence of unsuspected retro-odontoid pseudotumor (ROP) as detected in cone beam computed tomography examination. Additionally, we examined patient age, sex, and presence and severity of cervical osteoarthritis (OA) as potential risk factors for ROP. Study DesignWe retrospectively analyzed de-identified CBCT scans of 455 patients from the Division of Oral and Maxillofacial Radiology at the University of Connecticut School of Dental Medicine. Identification of likely ROP was completed through a likelihood scoring scale (1-4) due to the lack of magnetic resonance images. Severity of cervical OA was determined using 5 osteoarthritic features. An ordinal logistic regression model was used to link potential risk factors to ROP. ResultsIn total, 18 patients (3.9%) were classified with probable [11 patients (2.4%)] or definite [7 patients (1.5%)] likely ROP. Older age and the presence and severity of OA were significantly associated with higher ROP scores (P<0.001). There was no significant association of ROP likelihood and patient sex (P=.637). An increase of one year of age increased the chance of a patient having a higher ROP likelihood score (P<0.001). The age-adjusted chance of having a more severe ROP increased with moderate to severe OA (P≤ 0.017). ConclusionsPrevalence of likely ROP increases with age and OA but is not associated with sex. Individuals with moderate or severe OA are more likely to have ROP. Statement of Clinical RelevancePatients with retro-odontoid pseudotumor may experience spinal cord compression, which can result in adverse health effects. Clinicians should be aware of the appearance of this lesion on CBCT scans and be knowledgeable of the associations with increasing age and osteoarthritis.

Sensitivity and specificity for detecting pseudotumors in patients with hip resurfacing arthroplasty, metal-on-metal or metal-on-polyethylene total hip arthroplasty-MRI versus ultrasonography performed by an orthopedic surgery resident.

Metal artifact reduction sequence magnetic resonance imaging (MRI) scan is a common method to detect adverse reaction to metal debris in total hip arthroplasty (THA). It might be quicker and cheaper if ultrasonography (US) could screen for the need for an MRI. However, both require trained personnel. We aimed to investigate the sensitivity and specificity of US for detecting pseudotumors (PT) when performed by an orthopedic surgery resident compared to MRI. We also investigated the sensitivity and specificity of US to detect PTs in obese and non-obese patients. We examined 205 patients with hip resurfacing arthroplasty, metal-on-metal or metal-on-polyethylene THA with both MRI and US. US was performed by an orthopedic surgery resident who was trained according to a standardized training program in musculoskeletal US. Results from MRI were used as gold standard. US had a sensitivity of 0.92 (95% CI 0.81-0.98) and specificity of 0.94 (95% CI 0.89-0.97) for detecting PT. It had a positive predictive value of 0.84 (95% CI 0.73-0.91) and a negative predictive value of 0.97 (95% CI 0.93-0.99). US performed similarly in obese and non-obese patients. US had a high sensitivity and specificity for detecting PT when performed by an orthopedic surgery resident. Trained orthopedic surgeons could screen for the need of an MRI scan when searching PTs.

Suspicion of Recurrent Osteosarcoma in a Patient with Pseudotumour Adjacent To the Endoprosthesis.

PurposePseudotumor is a rare complication after arthroplasty, most often of the hip joint, in response to metal particles present in the implant. There are merely sporadic reports of pseudotumor in patients with bone sarcoma after sparing surgery with endoprosthesis implant. The aim of this study is to present the characteristic imaging features of pseudotumor.Case reportWe present a case of a 21-year-old male patient in whom a scheduled follow-up ultrasound revealed a painless lesion suspected of local recurrence at the border of the endoprosthesis and the bone stump 3.5 years after the end of treatment for osteosarcoma of the femur. Histopathology of the biopsy specimen revealed that the lesion was a pseudotumor.ConclusionsAlthough pseudotumor is sporadic in patients treated with endoprosthesis for bone sarcoma, their prolonged survival could bear the risk of such a complication. Imaging studies, in particular ultrasound, may be helpful in differentiating from local recurrence of sarcoma, however, the histopathology of the specimen obtained by open biopsy at a reference center is crucial for the final diagnosis.

Postoperative Regression of Retro-odontoid Pseudotumor After Atlantoaxial Posterior Fixation: 11 Years of Experience in Patients With Atlantoaxial Instability.

Case series study. The aim was to investigate the incidence of retro-odontoid pseudotumor in patients with atlantoaxial instability (AAI) and evaluate pseudotumor regression after posterior fixation. The incidence of retro-odontoid pseudotumor in atlantoaxial instability patients remains uncertain. Moreover, the regression of retro-odontoid pseudotumor after posterior fixation in patients with various underlying diseases needs to be further investigated. From July 2004 to August 2015, 175 patients with AAI underwent posterior fixation operations at our institution. After excluding 11 patients (previous operation, n = 4; history of tumor, n = 7), the final study population comprised 164 patients. The final study population was categorized according to their underlying diseases (rheumatoid arthritis [RA], os odontoideum, atlanto-occipital assimilation, dens fracture, AAI of unknown cause, etc.) and age (adult and pediatric groups). The incidence of retro-odontoid pseudotumor in each group was analyzed. Pre- and postoperative magnetic resonance or computed tomography images were reviewed to assess its regression following surgery. Of the 164 patients included, 38 had retro-odontoid pseudotumor (23.2%). Three were diagnosed with RA and the rest were non-RA patients including os odontoideum (n = 12), dens fracture (n = 6), atlanto-occipital assimilation (n = 4), Morquio syndrome (n = 1), and AAI of unknown cause (n = 12). Pseudotumor size regressed in all 38 patients after atlantoaxial posterior fixation. There was a statistically significant decrease in pseudotumor size (the length between the anterior border of the odontoid process to the posterior border of the pseudotumor) from a mean length of 17.7 to 14.9 mm (P < 0.001). The patients had various underlying diseases and the overall incidence of retro-odontoid pseudotumor in patients with symptomatic AAI was 23.2% at our institution during the past 11 years. All patients who underwent posterior fixation for AAI showed a statistically significant decrease in pseudotumor size. 4.

Longitudinal Followup of Incidentally Detected Pseudotumors in Patients with Metal on Metal Implants: A Retrospective Study.

Background:This study describes the significance and temporal evolution of incidentally detected, presumed, metal-induced reactive periprosthetic masses in patients with metal on metal (MoM) hip arthroplasty and its management. The literature concerning the temporal evolution of these lesions is meagre and so it is still unclear, whether asymptomatic patients with periprosthetic collections should undergo revision.Materials and Methods:Patients with MoM hip replacements fitted with a recalled implant (ASR, DuPuy) often undergo magnetic resonance imaging with metal artifact reduction sequences to look for complications. From a cohort of 136 asymptomatic patients, with 181 MoM hips, hips with a mention of periprosthetic masses in their reports at first presentation, and a repeat scan within 6 months to 3 years were selected for this retrospective study. Patients with complications such as loosening, osteomyelitis, and muscle/tendon tears were excluded from the study, and the final study cohort consisted of 55 MoM hips and 61 periprosthetic masses. Ethics committee approval is not required in our institution for retrospective studies. The followup scans of each patient were compared, and the periprosthetic masses were described to have progressed, regressed, or remained unchanged.Results:Comparison revealed that 29 of the 61 reactive masses remained unchanged, 20 regressed, while only 12 showed progression. The study, therefore, has maximum power as the outcome of interest, i.e., regression or unchanged status of the pseudotumors, was seen in approximately 80% (more than half) of the study group. The P value of the study was < 0.005.Conclusion:Periprosthetic soft tissue masses are not uncommon in patients with MoM hips. The majority of them in asymptomatic individuals remain stable or regress in the short to medium term, and close followup or decisions on revision surgery may not be warranted in asymptomatic patients.

Asymptomatic Pseudotumors in Patients with Taper Corrosion of a Dual-Taper Modular Femoral Stem: MARS-MRI and Metal Ion Study.

Modularity in total hip arthroplasty facilitates intraoperative restoration of patient anatomy. Although dual-taper modular total hip arthroplasty offers potential advantages for optimizing the hip center of rotation, it has been associated with modular taper corrosion. This corrosion has led to adverse local tissue reactions (pseudotumors) at the neck-stem junction and elevated metal-ion levels. However, the occurrence of taper-corrosion-related pseudotumors in patients who remain asymptomatic following total hip arthroplasty with a dual-taper modular femoral stem remains largely unknown. The aims of this study were (1) to determine the prevalence of asymptomatic pseudotumors by utilizing metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) and (2) compare serum metal-ion levels between symptomatic and asymptomatic patients with a dual-taper modular stem total hip replacement. We performed a retrospective cross-sectional study of 97 consecutive patients who had been treated with a dual-taper modular femoral stem total hip arthroplasty. Eighty-three patients were stratified into symptomatic and asymptomatic groups and evaluated with MARS-MRI, measurement of serum metal-ion levels, and the University of California at Los Angeles (UCLA) functional hip score. The prevalence of pseudotumors as determined with MARS-MRI was 15% in our asymptomatic patients and 36% in the overall cohort. The median serum cobalt level and cobalt/chromium ratio were significantly higher in patients with a pseudotumor than in those without a pseudotumor (8.0 versus 2.0 μg/L [p = 0.004] and 10.3 versus 2.4 μg/L [p = 0.012], respectively). However, there was no significant difference in the serum cobalt level or cobalt/chromium ratio between symptomatic patients with a pseudotumor and asymptomatic patients with a pseudotumor (7.6 versus 6.2 μg/L [p = 0.37] and 8.3 versus 10.6 μg/L [p = 0.46], respectively). The UCLA scores of asymptomatic patients with a pseudotumor were similar to those of patients without a pseudotumor (6.7 versus 6.6). The prevalence of asymptomatic taper-corrosion-related pseudotumors on MARS-MRI in this study demonstrated that the absence of symptoms does not exclude the presence of adverse local tissue reactions. Elevated cobalt levels and cobalt/chromium ratios were associated with the presence of pseudotumors in asymptomatic and symptomatic patients. Cross-sectional imaging such as MARS-MRI is indicated for patients with elevated metal-ion levels. A longitudinal study is required to determine whether asymptomatic patients with taper-corrosion-related pseudotumors will develop symptoms with time. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Goals and Challenges of Identifying Asymptomatic Pseudotumors in Patients Treated with Total Hip Arthroplasty

This paper sheds light on the management of patients who have a recalled dual-taper modular total hip replacement in place. The authors report on 83 patients divided into 2 groups: symptomatic (23) and asymptomatic (60). A pseudotumor was identified with metal artifact reduction sequence magnetic resonance imaging (MARS-MRI) in 30 (36%) of the 83 patients. Nine (15%) of the 60 asymptomatic patients and 21 (91%) of the 23 symptomatic patients had a pseudotumor. Patients with a pseudotumor had a significantly higher cobalt level (8.0 μg/L) compared with those with no pseudotumor (2.0 μg/L). On the basis of this finding, the authors recommend MARS-MRI for all patients with elevated cobalt levels, even in the absence of hip symptoms. If the goal is to minimize cost associated with MRI scans, then the authors’ recommendation of obtaining them only when the metal-ion level is elevated is sound. If the goal is to minimize any irreversible soft-tissue …

Sensitivity and Specificity of Metal Ion Levels in Predicting “Pseudotumors” due to Taper Corrosion in Patients With Dual Taper Modular Total Hip Arthroplasty

BackgroundCurrently, no serum metal ion threshold exists to identify adverse tissue reactions in total hip arthroplasty (THA) patients with taper corrosion. Our study aims to investigate the sensitivity and specificity of serum metal ions in detecting taper corrosion related pseudotumors in patients with dual taper modular THA. MethodsA total of 148 patients with dual taper modular THA were investigated: (1) 90 patients with pseudotumors detected with metal artifact reduction sequence-magnetic resonance imaging (MARS-MRI) and (2) 58 patients without pseudotumors on MARS-MRI. Receiver operating characteristic curves were constructed to determine the sensitivity and specificity using different metal ion thresholds. The severity of intraoperative tissue damage was correlated with preoperative metal ion levels. ResultsPseudotumor was associated with higher cobalt (5.0 μg/L vs 3.7 μg/L, P < .01) and Co/Cr ratio (6.0 vs 3.7, P < .01). The sensitivity and specificity for cobalt level of 2.8 μg/L and Co/Cr ratio of 3.8 in detecting taper corrosion–related pseudotumors on MARS-MRI was 88% and 32% and 70% and 50%, respectively. Higher intraoperative tissue damage grades demonstrated significantly higher Co/Cr ratios (8.6 vs 3.4, P = .03). ConclusionAlthough metal ion levels alone should not be relied on as the sole parameter to determine revision surgery, cobalt level >2.8 μg/L and the Co/Cr ratio >3.8 are useful clinical diagnostic adjuncts in the systematic clinical evaluation for taper corrosion–related adverse tissue reactions in patients with dual modular taper THA.

What Is the Natural History of Asymptomatic Pseudotumors in Metal-on-metal THAs at Mid-term Followup?

The risk of early revision because of pseudotumors in patients who have undergone large-head metal-on-metal (MoM) total hip arthroplasty (THA) is well documented. However, the natural history of asymptomatic pseudotumors or of MoM articulations without pseudotumors is less well understood. The aim of our study was to investigate the natural history of primary MoM THA at mid-term followup. The purposes of this study were: (1) Did previously detected pseudotumors persist or worsen in asymptomatic patients at mid-term followup; and if so, did any of them require revision THA? (2) Did new pseudotumors form in asymptomatic patients at mid-term followup? (3) What happened to serum trace metal ions at mid-term followup? (4) Were postoperative patient-reported outcome measures (PROMs) maintained at mid-term followup? Seventy-one patients who underwent a MoM THA using a Metasul LDH implant with a Durom acetabular cup and an M/L Taper stem between September 2005 and October 2008 were reviewed. All patients for this study were part of two previously published studies from our early followup. Data from the previous studies were used for comparison only. Two of the 71 patients (2.8%) were lost to followup. The mean age at operation was 56 years (range, 34-68 years). There were 24 female patients. All patients had serum trace metal ions testing, ultrasound imaging, and PROMs at a mean 3.5 years (early followup) after the index operation (range, 3-5 years) and delayed followup at a mean 7 years (range, 6.5-9 years). The indication to undertake revision THA was based on clinical evaluation and not solely on the investigation results. Twenty-three of 71 patients (32%) had a positive ultrasound scan for pseudotumor at early followup. Of these, eight patients underwent revision THA (11% of MoM THA or 35% of patients with an early positive ultrasound scan). The mean time between positive ultrasound scan and revision surgery was 13 months (range, 5-22 months). Of the remaining 15 patients with pseudotumor noted on early ultrasound, 12 had persistent pseudotumor, two resolved, and one was lost to followup. Six patients (13%) with a normal ultrasound scan at early followup showed new ultrasound findings at delayed followup. Of these, four (8%) were conclusively diagnosed as pseudotumor and one was revised. Serum trace metal ion increased at mid-term followup in the seven cases that showed an increase in volume of pseudotumor. Of the five patients in whom the volume of pseudotumor decreased on ultrasound at mid-term followup, three showed a decrease in serum trace ions levels, whereas two showed an increase. New-onset pseudotumors at mid-term followup was associated with an increase in serum trace metal ions at mid-term followup only in two of six cases. PROMs at mid-term followup of patients in this study remain high. At mid-term followup, approximately 35% of patients who develop an early pseudotumor undergo revision arthroplasty, whereas the remaining are asymptomatic. The incidence of new-onset ultrasound findings suggestive of pseudotumors at mid- to long-term followup is approximately 8% and these require continued surveillance. Level II, prognostic study.

Gluteal muscle fatty atrophy is not associated with elevated blood metal ions or pseudotumors in patients with a unilateral metal-on-metal hip replacement

Background and purpose — There are no international guidelines to define adverse reaction to metal debris (ARMD). Muscle fatty atrophy has been reported to be common in patients with failing metal-on-metal (MoM) hip replacements. We assessed whether gluteal muscle fatty atrophy is associated with elevated blood metal ion levels and pseudotumors.Patients and methods — 263 consecutive patients with unilateral ASR XL total hip replacement using a posterior approach and with an unoperated contralateral hip were included in the study. All patients had undergone a standard screening program at our institution, including MRI and blood metal ion measurement. Muscle fatty atrophy was graded as being absent, mild, moderate, or severe in each of the gluteal muscles.Results — The prevalance of moderate-to-severe gluteal muscle atrophy was low (12% for gluteus minimus, 10% for gluteus medius, and 2% for gluteus maximus). Muscle atrophy was neither associated with elevated blood metal ion levels (> 5 ppb) nor with the presence of a clear (solid- or mixed-type) pseudotumor seen in MRI. A combination of moderate-to-severe atrophy in MRI, elevated blood metal ion levels, and MRI-confirmed mixed or solid pseudotumor was rare. Multivariable regression revealed that “preoperative diagnosis other than osteoarthrosis” was the strongest predictor of the presence of fatty atrophy.Interpretation — Gluteal muscle atrophy may be a clinically significant finding with influence on hip muscle strength in patients with MoM hip replacement. However, our results suggest that gluteal muscle atrophy seen in MRI is not associated with either the presence or severity of ARMD, at least not in patients who have been operated on using the posterior approach.

Prevalence of Pseudotumor in Patients After Metal-On-Metal Hip Arthroplasty Evaluated with Metal Ion Analysis and MARS-MRI

The purpose of this study is to quantify the prevalence of pseudotumors in patients with well-functioning and painful metal-on-metal total hip arthroplasty, to characterize the pseudotumor with the use of MARS-MRI, and to assess the relationship between pseudotumors and metal ions. We retrospectively reviewed 102 single surgeon patients. The results showed that 68.6% developed pseudotumor with 60.9% of the asymptomatic group developing pseudotumor. The symptomatic group had a higher proportion of patients with elevated serum cobalt levels (P=0.035). There was no difference found with elevated metal ions and prevalence of pseudotumor, but elevated cobalt levels were associated with larger pseudotumor size (P=0.001). The available evidence indicated that most patients that develop pseudotumors are asymptomatic, and that elevated serum cobalt levels may be associated with symptoms and pseudotumor size.

A pelvic pseudotumor in a nonhemophilic patient: an unusual presentation.

Hemophilic pseudotumor is a rare complication of hemophilia, occurring in 1 to 2 percent of individuals with severe factor VIII or factor IX deficiency. A 35-year-old male presented with a swelling in the right lower abdomen for 3 months. There was no history of trauma. Examination revealed a swelling over the right iliac fossa. Right hip showed 30° flexion deformity. Blood investigations like complete blood count, APTT, PT, bleeding and clotting time, and fibrinogen were all normal. Plain radiograph and MRI showed a lytic lesion in the right iliac wing. Excision biopsy of the swelling showed organized hematoma with a fibrous capsule suggestive of a pseudotumor. Further haematological workup like factors VIII and IX was normal. At 2 years follow-up, there was no recurrence. We report this case of pseudotumour in patient without any bleeding disorder. Such case has not been reported in literature to the best of our knowledge.

Repeated magnetic resonance imaging in 154 hips with large-diameter metal-on-metal hip replacement

Background and purpose — The US Food and Drug Administration and the UK Medicines and Health Regulation Agency recommend using MRI in the evaluation of patients with large-diameter metal-on-metal (LD-MoM) hips. Such recommendations do not take into account the relevance of repeated cross-sectional imaging. We therefore investigated the natural course of pseudotumors in patients with LD-MoM hip replacements.Patients and methods — Of 888 ASR patients (1,036 hips) 674 patients (798 hips) underwent 2 follow-up visits at our institution. Of these, we identified 124 patients (154 hips) who had undergone repeated clinical assessment including MRI and whole-blood metal ion assessment.Results — A change in classification in imaging findings between the 2 MRIs was seen in 17 of the 154 hips (11%). In 13 hips (8%), a significant progression of the pseudotumor was evident, while in 4 (3 %) there was a retrogressive change. 10 of these 13 hips had had a normal first MRI. Patients with a progressive change in the scans did not differ significantly from those without a change in MRI classification regarding follow-up time, time interval between MRIs, or changes in whole-blood Cr and Co levels between assessments.Interpretation — A change in classification was rare, considering that all patients had a clinical indication for repeated imaging. Progression of the findings did not appear to correlate clearly with symptoms or whole-blood metal values.

Cause for Concern: Pseudotumors in Patients with Hip Resurfacing

The Journal of Bone & Joint Surgery: September 4, 2013 - Volume 95 - Issue 17 - p e127 doi: 10.2106/JBJS.M.01029

High Prevalence of Pseudotumors in Patients with a Birmingham Hip Resurfacing Prosthesis

Recently, concern has emerged about pseudotumors (lesions that are neither malignant nor infective in the soft tissues surrounding total hip arthroplasty components) after hip arthroplasties with metal-on-metal bearings. Patients treated in our hospital for degenerative arthritis of the hip with a Birmingham Hip Resurfacing (BHR) prosthesis were invited to return for follow-up evaluation. The prevalence and clinical relevance of pseudotumors were investigated. Risk factors for pseudotumor formation were sought. A single-center cross-sectional prospective cohort study was conducted and included all patients who received a BHR from 2005 to 2010 in Martini Hospital, Groningen, The Netherlands. Data were collected on patient and surgical characteristics, clinical hip outcome scores (Harris hip score and Oxford score), serum metal ion levels (cobalt and chromium), and radiographs. A computed tomographic scan (without metal suppression) was made. In patients who had a revision, tissue samples were histologically examined. Originally, there were 129 patients with 149 BHRs. Four patients (six hips; 4%) were lost to follow-up. Our final cohort consisted of 125 patients (143 hips). From this final cohort, eleven patients (twelve hips) had a revision, and three of them (three hips) had the revision before the present study was conducted. Seven patients (eight hips; 5.6%) had a revision because of a symptomatic pseudotumor. Survival analysis showed an implant survival rate of 87.5% at five years (failure was defined as a revision for any reason). A pseudotumor was found on computed tomography in thirty-nine patients (forty hips; 28%). Of those patients, ten (eleven hips; 28%) had complaints involving groin pain and discomfort, a noticeable mass, or paresthesia. Symptomatic pseudotumors were significantly larger than asymptomatic pseudotumors (a mean volume of 53.3 cm3 compared with 16.3 cm3; p = 0.05). A serum cobalt level of >85 nmol/L was a predictor for pseudotumor formation (odds ratio, 4.9). Pseudotumor formation occurred in 28% of hips after an average follow-up of forty-one months. Most pseudotumors (72.5%) were asymptomatic. Larger pseudotumors were associated with more complaints. Survival analysis showed an implant survival of 87.5% at five years. Failure occurred in 5.6% (eight) of 143 hips because of a symptomatic pseudotumor.

The John Charnley Award: Diagnostic Accuracy of MRI Versus Ultrasound for Detecting Pseudotumors in Asymptomatic Metal-on-Metal THA

The prevalence of pseudotumors in patients with large-head metal-on-metal (MOM) THA has been the subject of implant recalls and warnings from various regulatory agencies. To date, there is no consensus on whether ultrasound or MRI is superior for the detection of pseudotumors. We prospectively compared ultrasound to MRI for pseudotumor detection in an asymptomatic cohort of patients with MOM THAs. We also compared ultrasound to MRI for assessment of pseudotumor growth and progressive soft tissue involvement at a 6-month interval. We enrolled 40 patients with large-head MOM THAs in the study. The mean age was 54 years (range, 34-76 years). The mean time from surgery was 54 months (range, 40-81 months). There were 28 men and 12 women. All patients underwent ultrasound and MRI using slice encoding for metal artifact correction. The gold standard was defined as follows: if both ultrasound and MRI agreed, this was interpreted as concordant and the result was considered accurate. Ultrasound and MRI agreed in 37 of 40 patients (93%). The prevalence of pseudotumors was 31% (12 of 39) in our cohort. Twenty-three of 39 patients (59%) had completely normal tests and four (10%) had simple fluid collections. Ultrasound had a sensitivity of 100% and specificity of 96% while MRI had a sensitivity of 92% and specificity of 100%. A negative ultrasound rules out pseudotumor in asymptomatic patients as this test is 100% sensitive. Given its lower cost, we recommend ultrasound as the initial screening tool for pseudotumors.

Extra-articular inflammatory pseudotumor after well-fixed metal-polyethylene total hip arthroplasty

Objective To retrospectively analyze the diagnosis and treatment of the extra-articular inflammatory pseudotumor after well-fixed metal-polyethylene total hip arthroplasty (THA).Methods From March 2006 to June 2011,7 patients (7 hips) who presented with a progressive pain and/or swelling,discomfort in groin or upper thigh after metal-polyethylene THA were admitted to our hospital.There were 2 males and 5 females,with an average age of 48.8 years (range,32-65 years).All 7 patients were identified with a periprosthetic osteolysis at the acetabular and/or femoral components and a mass in the iliac fossa or the thigh; however,the components were all well-fixed.The masses were confirmed by CT scanning and/or ultrasound examination.The revision procedures were done through ilioinguinal approach and posterior-lateral approach,and the pseudotumors were excised and osteolytic lesions were debrided and packed tightly with morselized cancellous allograft.The liner and femoral head were also exchanged at the same time.Clinical and radiographic outcomes of revision THA were evaluated.Results All 7 patients were followed up for 3-42 months (average,30 months).At final follow-up,all hips were functioning well and the average Harris hip score was 92.4.All acetabular components remained radiographically well-fixed.All cavitary defects had complete radiographic incorporation of the bone grafts.There were no new pseudotumor or osteolytic lesions identified,and no revision of the components.Conclusion The presence of abdominal or pelvic pseudotumor in patient with a THA may be associated with polyethylene wear.Once the extra-articular pseudotumor and the periprosthetic osteolysis are identified,the surgical treatment,including pseudotumor excise,osteolytic lesion debride and bone defect grafting and bearing surface exchange,can achieve retention of well-fixed components. Key words: Arthroplasty, replacement, hip; Polyethylene; Granuloma, plasma cell

Pseudotumors in Association with Well-Functioning Metal-on-Metal Hip Prostheses

Many papers have been published recently on the subject of pseudotumors surrounding metal-on-metal hip resurfacing and replacement prostheses. These pseudotumors are sterile, inflammatory lesions within the periprosthetic tissues and have been variously termed masses, cysts, bursae, collections, or aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL). The prevalence of pseudotumors in patients with a well-functioning metal-on-metal hip prosthesis is not well known. The purpose of this study was to quantify the prevalence of pseudotumors adjacent to well-functioning and painful metal-on-metal hip prostheses, to characterize these lesions with use of magnetic resonance imaging, and to assess the relationship between their presence and acetabular cup position with use of three-dimensional computed tomography. We performed a case-control study to compare the magnetic resonance imaging findings of patients with a well-functioning unilateral metal-on-metal hip prosthesis and patients with a painful prosthesis (defined by either revision arthroplasty performed because of unexplained pain or an Oxford hip score of <30 of 48 possible points). Thirty patients with a painful hip prosthesis and twenty-eight controls with a well-functioning prosthesis were recruited consecutively. All patients also underwent computed tomography to assess the position of the acetabular component. Thirty-four patients were diagnosed with a pseudotumor. However, the prevalence of pseudotumors in patients with a painful hip (seventeen of thirty, 57%) was not significantly different from the prevalence in the control group (seventeen of twenty-eight, 61%). No objective differences in pseudotumor characteristics between the groups were identified. No clear association between the presence of a pseudotumor and acetabular component position was identified. The Oxford hip score in the group with a painful hip (mean, 20.2; 95% confidence interval [CI], 12.7 to 45.8) was poorer than that in the control group (mean, 41.2; 95% CI, 18.5 to 45.8; p ≤ 0.0001). A periprosthetic cystic pseudotumor was diagnosed commonly (in thirty-four [59%] of the entire study cohort) with use of metal artifact reduction sequence (MARS) magnetic resonance imaging in this series of patients with a metal-on-metal hip prosthesis. The prevalence of pseudotumors was similar in patients with a well-functioning hip prosthesis and patients with a painful hip. Pseudotumors were also diagnosed commonly in patients with a well-positioned acetabular component. Although magnetic resonance imaging is useful for surgical planning, the presence of a cystic pseudotumor may not necessarily indicate the need for revision arthroplasty. Further correlation of clinical and imaging data is needed to determine the natural history of pseudotumors to guide clinical practice.

Intraventricular inflammatory pseudotumor: Report of two cases and review of the literature

Inflammatory pseudotumors (IP) are non-neoplastic lesions characterized by collagenous stroma and polyclonal mononuclear infiltrates. It is best characterized in the lung, but can occur in the CNS, mimicking a neoplastic process. We discuss the available literature and our cases in order to elucidate best medical practices when confronted with such a lesion. We report on two cases of intraventricular inflammatory pseudotumor in patients who presented with symptoms of CSF obstruction. Both patients were treated surgically with significant clinical improvement. Histopathologically, both specimens revealed a plasma cell granuloma variant of IP. A Medline search for English articles identified 46 cases of CNS IP, only eight of which were located within the ventricle. As with our case, most patients presented due to CSF obstruction or mass effect. Radiographically, the lesions have a variable appearance although most enhanced with gadolinium. Complete resection was achieved in 67% with a 12% rate of recurrence. With incomplete resection or biopsy alone, progression is seen despite steroid or radiation administration. Malignant transformation was only reported once. CNS IP is a rare pathological entity that cannot be diagnosed through clinical presentation or radiographic characteristics, but rather through a careful neuropathological inspection. The available literature suggests that complete resection with close follow-up is necessary.

Pseudotumor orbitario refractario tratado con rituximab en paciente con lupus eritematoso sistémico. A propósito de un caso

Ocular manifestations in Systemic Lupus Erythematosus (SLE) are relatively frequent, with a major prevalence of the Keratoconjunctivitis sicca. Nevertheless, the appearance of unilateral exophthalmos secondary to orbital pseudotumor in patients with SLE is extremely rare 1–7 , and on occasion it can be refractory to conventional pharmacological treatment (glucocorticoids and immunosuppressants). We present the case of a patient with SLE and orbital pseudotumor refractory to treatment with Cyclophosphamide (CF) and an excellent clinical response, with disappearance of the ophthalmological condition after the beginning of therapy with Rituximab (1g×2), continuing after the infusion of two complete cycles without incidents.