Post-operative regression of retro-odontoid pseudotumors treated with and without fusion.

PURPOSE: Retro-odontoid pseudotumor is common in elderly people and is a cause of cervical myelopathy. The goal of the study was to investigate surgical procedures, outcomes, and post-operative spontaneous regression of posterior cervical retro-odontoid pseudotumors. METHODS: The subjects were 29 patients who underwent surgery for myelopathy due to a retro-odontoid pseudotumor around the craniocervical region at 9 facilities and were followed-up for an average of 54 months (range 12-96 months). Data were collected in a multicenter review of a retrospective database. Comparisons were performed between cases treated with and without fusion. RESULTS: The JOA recovery rate at final follow-up did not differ significantly between the fusion (n = 17, including all 15 patients with atlantoaxial subluxation) and non-fusion (n = 12) groups. However, pseudotumor regression was significantly more frequent in the fusion group (100% vs. 42%, p < 0.01). In all patients, regression cases had significantly higher rates of contrast enhancement of the pseudotumor on pre-operative T1 gadolinium-enhanced MRI (68% vs. 14%, p = 0.013) and of JOA recovery (50% vs. 30%, p < 0.01). CONCLUSIONS: Regression of pseudotumor occurred in all cases treated with fusion surgery. There was a significant difference in pseudotumor regression with or without fusion, and regression was significantly related to gadolinium enhancement on MRI. Therefore, it is preferable to use fusion surgery for a retro-odontoid pseudotumor that shows contrast enhancement, even if there is no apparent instability pre-operatively. These slides can be retrieved under Electronic Supplementary Material.

Plasma Cell Granuloma of the Jaw and the Infratemporal Fossa: A Clinical Case.

Plasma cell granuloma or inflammatory pseudotumor (IPT) is diagnosed by a process of elimination. The precise etiology is unknown, although it can occur after a bout of periodontal infection. This report describes the various stages of progression for this ailment. A 49-year-old woman with no noteworthy medical history presented with a recurrent periodontal abscess accompanied by progressive and severe destruction of the right maxilla. There was invasion of the infratemporal fossa and very tight trismus. Histologic examination indicated a reactive plasma cell granuloma. IPT is an entity recognized by the World Health Organization. A triggering infectious or inflammatory factor is often present. In the maxilla, progression is very aggressive. Treatment relies on corticotherapy, with or without radiotherapy, and administration of cyclosporine.

Implant Failure After Motec Wrist Joint Prosthesis Due to Failure of Ball and Socket-Type Articulation-Two Patients With Adverse Reaction to Metal Debris and Polyether Ether Ketone.

We describe 2 cases of articulation-related failures resulting in revision surgery after a Motec total wrist arthroplasty: one with an adverse reaction to metal debris and the other with an adverse reaction to polyether ether ketone. In the first patient, blood cobalt and chrome levels were elevated and magnetic resonance imaging showed clear signs of a pseudotumor. The other patient had an extensive release of polyether ether ketone particles into the surrounding synovia due to adverse wear conditions in the cup, leading to the formation of a fluid-filled cyst sac with a black lining and diffuse lymphocyte-dominated inflammation in the synovia. We recommend regular follow-up including x-rays, monitoring of cobalt and chrome ion levels, and a low threshold for cross-sectional imaging in patients who have undergone total wrist arthroplasty with a Motec joint prosthesis. Wear-related problems can also develop in implants in which polyether ether ketone is the bulk material.

Higher Prevalence of Mixed or Solid Pseudotumors in Metal-on-Polyethylene Total Hip Arthroplasty Compared With Metal-on-Metal Total Hip Arthroplasty and Resurfacing Hip Arthroplasty.

BACKGROUND: Pseudotumors are a common finding in metal-on-metal (MoM) total hip arthroplasty (THA) and resurfacing hip arthroplasty (RHA). However, information on pseudotumors in metal-on-polyethylene (MoP) THA is limited. METHODS: One hundred eleven patients with 148 hip articulations-30 MoM THA, 47 MoM RHA, and 71 MoP THA-participated in a cross-sectional study at mean 7.1 (range: 0.2-21.5) years postoperatively. Patients were evaluated with metal artifact reducing sequence magnetic resonance imaging, measurements of metal ions, clinical scores of Harris Hip Score, Oxford Hip Score, the Copenhagen Hip and Groin Outcome Score, and conventional radiographs. RESULTS: Pseudotumors were present in 13 of 30 (43%) MoM THA, 13 of 47 (28%) MoM RHA, and 29 of 71 (41%) MoP THA patients, which was a similar prevalence (P = .10). The prevalence of mixed or solid pseudotumors was significantly higher in patients with MoP THA (n = 10) compared to MoM THA (n = 3) and MoM THA (n = 0), (P = .01). Hips with a mixed or solid pseudotumor had significantly poorer scores of Harris Hip Score (P = .01) and OHS (P = .002) and higher metal ion levels of cobalt (P = .0009) compared to hips without a pseudotumor or with a cystic pseudotumor. CONCLUSION: Pseudotumors have primarily been associated with MoM hip articulations, but we found a similar pseudotumor prevalence in MoP THA, which is the most common bearing worldwide. Mixed or solid pseudotumors were more often seen in MoP THA compared with MoM hip articulations, and patients with a mixed or solid pseudotumor had poorer clinical scores and higher metal ion levels than patients without a pseudotumor or with a cystic pseudotumor.

Aggressive inflammatory pseudotumor of the mandible.

Inflammatory pseudotumor (IP) is a nongranulomatous inflammatory process with no apparent local or systemic cause. The distinction between IP and malignant tumor is of great clinical importance. The incidence of IP in the head and neck region is very low. Inflammatory pseudotumor is a distinct pathological entity rarely found in the jaw bones. A rare case of aggressive IP of the mandible is presented along with its clinicopathologic features and surgical management.

Treatment-refractory ALK-positive inflammatory myofibroblastic tumour of the oral cavity.

We present a challenging case of a previously healthy 23-year-old man who developed an inflammatory myofibroblastic tumour of the hard palate, harbouring a rearrangement of the anaplastic lymphoma kinase (ALK) locus. Despite surgical intervention, radiotherapy and ALK-inhibition therapy, the tumour recurred locally and metastasised to regional lymph nodes, and the patient passed away roughly 9 months after diagnosis from local progression. The rapid progression of this patient's disease and its resistance to treatment demonstrate the potentially aggressive clinical course of inflammatory myofibroblastic tumours. ALK-inhibition therapy was unsuccessful in this ALK-positive tumour, highlighting the need for further investigation of markers predictive of disease progression and treatment response.

Head and neck inflammatory pseudotumor: Case series and review of the literature.

Inflammatory pseudotumor (IP) is an uncommon idiopathic lesion that often imitates malignancy clinically and radiologically. Inflammatory pseudotumors have been found to occur in various sites but rarely in the head and neck. The histopathology, imaging, and treatment of three unique cases of head and neck inflammatory pseudotumors are described in this case series. Patients in Cases 1 and 2 presented with right level II neck mass and left parotid tail mass, respectively. The patient in Case 3 presented with otalgia, jaw pain and trismus, and a left parapharyngeal space mass. The tumors in Cases 1 and 3 significantly decreased in size with tapered courses of oral corticosteroids. The tumor in Case 2 was surgically excised without disease recurrence. Malignancy must be ruled out with incisional or excisional biopsy. Treatment includes surgical excision, oral corticosteroids, or both. The literature shows that radiotherapy and small-molecule inhibitors may be promising alternatives.

Inflammatory pseudotumour of the maxilla.

Inflammatory pseudotumour (IP), also known as inflammatory myofibroblastic tumour (IMT), is a rare lesion of the maxillofacial skeleton and a diagnosis by exclusion. We describe three cases which affected the maxilla, two women and one man of ages 67, 56 and 70 years at presentation. All showed the typical, rather non-specific histopathological features. IgG4-positive plasma cells varied greatly in prominence, and none of the three lesions expressed ALK-1. Both women responded to steroids and radiotherapy, though one also required azathioprine. Despite maxillectomy, radiotherapy, steroids and cyclophosphamide, the man suffered intracranial spread and succumbed to persistent disease. The cases described here demonstrate the clinicopathological difficulties presented by this entity and its aggressive, unpredictable behaviour.

Periprosthetic pathology in 'at risk' ceramic-on-polyethylene total hip arthroplasty: a clinical study using MARS-MRI in 50 patients.

PURPOSE: Recent studies of metal-on-metal (MoM) total hip arthroplasty (THA) using metal-artefact-reducing-sequence software for magnetic resonance Imaging (MARS-MRI) have revealed remarkable soft tissue pathology around the hip, usually referred to as pseudotumours. Case reports describe identical pathology in non-MoM THA, but descriptive overviews of MRI abnormalities in patients with non-MoM prosthesis are scarce. METHODS: A clinical study in a cohort of 50 ceramic-on-polyethylene (CoP) THA selected for high risk of peri-prosthetic pathology including 2 subgroups: (i) 40 patients with a high polyethylene (PE) wear rate (>0.2 mm per year) and 5-12 years follow-up; (ii) 10 patients with a 2 to 5 years follow-up and a documented history of persistent complaints. All patients were clinically evaluated, MARS-MRIs were completed and chrome and cobalt serum samples were taken. RESULTS: 17 scans were normal (34%). Periprosthetic fluid collections were seen as a bursae iliopsoas (n = 12, 24%), in the trochanter bursae (n = 4, 8%) and in the surgical tract (n = 9, 18%). 1 case demonstrated a cyst on MARS-MRI resembling a pseudotumour as seen with MoM THA (2%). Intraosseous acetabular cysts were seen in 12 cases (24%), intraosseous trochanteric cysts in 10 cases (20%). CONCLUSIONS: Soft tissue abnormalities after non-MoM THA are common in selected patients and can be clearly visualised with MARS-MRI. Pseudotumours as seen on MARS-MRI do occur in non-MoM hip arthroplasty but with low prevalence.

Pseudotumour incidence, cobalt levels and clinical outcome after large head metal-on-metal and conventional metal-on-polyethylene total hip arthroplasty: mid-term results of a randomised controlled trial.

We compared the incidence of pseudotumours after large head metal-on-metal (MoM) total hip arthroplasty (THA) with that after conventional metal-on-polyethylene (MoP) THA and assessed the predisposing factors to pseudotumour formation. From a previous randomised controlled trial which compared large head (38 mm to 60 mm) cementless MoM THA with conventional head (28 mm) cementless MoP THA, 93 patients (96 THAs: 41 MoM (21 males, 20 females, mean age of 64 years, standard deviation (sd) 4) and 55 MoP (25 males, 30 females, mean age of 65 years, sd 5) were recruited after a mean follow-up of 50 months (36 to 64). The incidence of pseudotumours, measured using a standardised CT protocol was 22 (53.7%) after MoM THA and 12 (21.8%) after MoP THA. Women with a MoM THA were more likely to develop a pseudotumour than those with a MoP THA (15 vs 7, odds ratio (OR) = 13.4, p < 0.001). There was a similar incidence of pseudotumours in men with MoM THAs and those with MoP THAs (7 vs 5, OR = 2.1, p = 0.30). Elevated cobalt levels (≥ 5 microgram/L) were only associated with pseudotumours in women with a MoM THA. There was no difference in mean Oxford and Harris hip scores between patients with a pseudotumour and those without. Contrary to popular belief, pseudotumours occur frequently around MoP THAs. Women with a MoM THA and an elevated cobalt level are at greatest risk. In this study, pseudotumours had no effect on the functional outcome after either large head MoM or conventional MoP THA.

Inflammatory pseudotumour of the mouth and maxilla.

AIM: To describe the clinicopathological and immunophenotypical findings of two cases of inflammatory pseudotumour in the oral cavity. METHODS AND RESULTS: The patients presented with a short history of swelling in the cheek and the maxilla respectively. Magnetic resonance imaging or computerised tomography scan showed space occupying lesions with infiltrative margins which were interpreted as aggressive malignant neoplasms. Histological examination showed fascicles of spindle cells in a background of chronic reactive inflammatory cells including plasma cells, typical of inflammatory pseudotumour. The spindle cells were positive for vimentin, smooth muscle actin and CD68, but were negative for follicular dendritic cell markers. The lymphocytes showed no light chain restriction. CONCLUSIONS: Inflammatory pseudotumour in the oral cavity is completely benign and simple excision is curative. However, it may be confused with a malignant tumour on clinical and radiographic grounds, and histologically the appearances can also be misinterpreted as those of a more aggressive lesion. Its correct recognition by the surgical pathologist is important to avoid unnecessarily radical and potentially mutilating surgery.

Mandibular haemophilic pseudotumour containing a fluid-fluid level.

Osseous haemophilic pseudotumours are uncommon. Mandibular haemophilic pseudotumours are rare, with only approximately 12 cases reported in the literature to date. We present imaging findings of a histopathologically proven mandibular haemophilic pseudotumour. A fluid-fluid level, hitherto not associated with this condition, is also described.

Inflammatory pseudotumor: report of a case in the mandible.

BACKGROUND: Intraoral inflammatory pseudotumor (IPT) is a rare, benign non-neoplastic lesion that presents as a rapidly growing mass with aggressive behavior, which can be mistaken for a malignant process. CASE REPORT: This article presents a rare case of IPT of the mandible in a 70-year-old male patient. Examination of the oral cavity revealed a hemorrhagic soft mass of the mandibular region. The patient was treated with surgery. Histologic examination of the resected specimen showed proliferation of fascicular spindle cells and a dense, chronic inflammatory cell infiltrate consisting of neutrophils, eosinophils, and lymphocytes. Immunohistochemically, the spindle cells expressed vimentin, α smooth muscle actin, and CD68, indicating a diagnosis of IPT. DISCUSSION: IPT is an unusual benign pathology in the oral and maxillofacial area. Because of its aggressive clinical and radiological features, it can be mistaken for a malignancy. We suggest that oral and maxillofacial surgeons should be aware of the specific features of IPT to avoid unnecessary aggressive treatments such as a radical resection.

Adverse reaction to metal release from a modular metal-on-polyethylene hip prosthesis.

A 70-year-old man with an uncemented metal-on-polyethylene total hip prosthesis underwent revision arthroplasty 33 months later because of pain, swelling and recurrent dislocation. There appeared to be corrosion and metal release from the prosthetic head, resulting in pseudotumour formation and severe local soft-tissue destruction. The corrosion occurred at the junction between the titanium-molybdenum-zirconium-iron taper and the cobalt-chrome-molybdenum head, but the mechanism was unproven.

Transcatheter arterial embolisation for paediatric inflammatory pseudotumour of the maxillary sinus.

BACKGROUND: Inflammatory pseudotumours are mostly seen in the lung, and occasionally in the head and neck region including the sinonasal area. Reported treatment modalities comprise corticosteroid treatment, surgical excision and radiotherapy. The latter option is required because wide surgical resection may be difficult for head and neck lesions, especially in children. However, clinicians should be aware of the risk of late-onset side effects of radiotherapy in children. CASE REPORT: We present a two-year-old girl with a massive inflammatory pseudotumour of the maxillary sinus. Transcatheter arterial embolisation was performed, and the lesion was successfully managed without additional therapy. There was no evidence of recurrence over the next five years. CONCLUSION: This is the first report presenting the utility of arterial embolisation for inflammatory pseudotumour.

Radiographic analysis of the cervical spine in patients with retro-odontoid pseudotumors.

STUDY DESIGN: A retrospective review of 10 consecutive patients with a noninflammatory retro-odontoid pseudotumor. OBJECTIVE: To examine the radiographic characteristics in patients with a retro-odontoid pseudotumor and to evaluate the efficacy of posterior fusion. SUMMARY OF BACKGROUND DATA: A retro-odontoid pseudotumor, a reactive fibrocartilaginous mass, is known to develop after chronic atlantoaxial instability; however, one-third of the reported cases showed no overt atlantoaxial instability. The pathomechanism for such "atypical" cases remains unclear, although altered cervical motion secondary to ossification of the anterior longitudinal ligament (OALL) or severe spondylosis has been implicated. METHODS: We reviewed the charts and radiographs of 10 patients with a retro-odontoid pseudotumor who underwent surgery. Preoperative radiographs were evaluated for atlas-dens interval (ADI), presence of OALL, range of motion, and segmental motion adjacent to the atlantoaxial joint. Computed tomography was evaluated for degenerative changes of zygapophysial joints. RESULTS: There were 6 men and 4 women. Atlantoaxial instability (ADI >4 mm) was observed in 2 patients. ADI was less than 3 mm in 5 patients. Frequent association of OALL (6 patients) and marked decrease in C2 to C7 range of motion (mean, 17.6 degrees ; range, 3 degrees-36 degrees ) were noted. Ankylosis of O-C1 was observed in 4 patients and C2 to C3 in 6. Severe degenerative change of C2 to C3 zygapophysial joint was observed in 4 patients. The patients underwent occipito-cervical fusion (9 patients) or direct removal of the pseudotumor (1 patient). Postoperative magnetic resonance imaging invariably demonstrated the mass regression. CONCLUSION: Retro-odontoid pseudotumors were not always associated with radiographic atlantoaxial instability. Our data indicate that extensive OALL and ankylosis of the adjacent segments are risk factors for the formation of the pseudotumor. Retro-odontoid pseudotumors may develop as an "adjacent segment disease" after altered biomechanics of the cervical spine, especially those in the adjacent segments. Posterior fusion was effective even in cases without radiographic atlantoaxial instability.

[The prototype of an expert system for the diagnosis of pseudotumorous lesions and tumors of the jaws: ADAPT-M. Archiviazione e Diagnosi Automatica di Pseudotumori e Tumori delle ossa Mascellari]. / Prototipo di un sistema esperto per la diagnosi delle lesioni pseudotumorali e tumorali dei mascellari: ADAPT-M.

Many different tumors and pseudotumors may affect the jaw bones. The number and the rarity of most of these lesions, however, make both classification and differential diagnosis quite difficult. Computer software for statistical calculations and logical-deductive reasoning on vast amounts of data can improve diagnostic skills. These applications are defined as computer-assisted decision-making, medical decision support, or expert systems. This study was aimed at developing a prototype probabilistic expert system, based upon knowledge from an "ad hoc"computerized data base, as an aid in the radiologic diagnosis of jaw tumors and pseudotumors. This program has been called ADAPT-M. The study considered 92 patients with benign space-occupying and fully documented lesions of the jaw bones. For each case, a list of parameters concerning different radiologic exams was considered. From all these pieces of information a data base was built, to calculate both the prevalence of each type of lesion and the frequency of many variables in the single conditions. For each kind of lesion 44 variables were considered. ADAPT-M used a formula based on Bayes' theorem to calculate the "a posteriori" probability of a diagnosis in the presence of a symptom. Overall diagnostic probability rate was high when the highest score hypothesis was matched with pathologic findings (80%) and even higher (96.1%) when the two most probable diagnoses were considered together. As expected, ADAPT-M had higher sensitivity when used with lesions with typical semiology. This results in an unquestionable limitation, especially in the patients in whom a predictive diagnosis would be most desirable. The creation of a larger data base of known cases and software development may help increase the diagnostic accuracy of the ADAPT-M system.

Pathologic supracondylar fracture due to osteolytic pseudotumor of knee following cementless total knee replacement.

Wear debris of polyethylene, polymethylmethacrylate, and metal have been recognized to be associated with foreign body reactions, osteolysis, and aseptic prosthetic loosening after joint replacement arthroplasty. Further, foreign body reaction due to the presence of extensive wear debris can cause aggressive granulomatous lesions and pathologic fracture. To our knowledge, there has been no previous report of pathologic fracture of the femur due to an agressive pseudotumor. This report describes a case of pathologic supracondylar fracture of the femur 6 years and 5 months after cementless total knee replacement arthroplasty. The fracture occurred through an aggressive expanding soft tissue mass that was a tumorlike lesion secondary to polyethylene wear debris. The lesion was associated with massive osteolysis around the femoral component of the total knee prosthesis.