Encephalic schistosomiasis is a rare and severe parasitic disease which manifests as granuloma formation around ectopic eggs that migrate to the brain. We present a rare case of a pseudotumoral form of Schistosoma japonicum in the brainstem that was initially misidentified as a malignant tumor. The patient presented with intermittent headaches, diplopia, and left limb weakness. Neurological examination revealed hypoesthesia of the left lower limb, limitation of right eye abduction, and decreased muscle strength of the left upper limb. The cerebrospinal fluid tested positive for antibodies against S. japonicum. After standard treatment for schistosomiasis, the patient achieved complete remission. This case highlights that encephalic schistosomiasis can occur in the brainstem and resemble a neoplasm on magnetic resonance imaging. Once diagnosed, however, complete remission is achievable by non-invasive medical treatment.

BACKGROUND: Metal-on-metal (MoM) total hip arthroplasty (THA) has been associated with adverse reactions to metal debris, presenting clinically as pseudotumors.
METHODS: This case report presents a female aged 73 year-old with MoM THA-related pseudotumor. After arthrotomy and bursectomy surgeries, histologic examinations of surgical specimens revealed a specific lymphocyte-dominant immunologic response, now known as aseptic lymphocyte-dominant vasculitis-associated lesion (ALVAL). Due to soft tissue persisting effusion after arthrotomy and bursectomy, revision surgery was then performed with ceramic-on-polyethylene THA. However, revision did not resolve the patient\'s symptoms. Here we describe our application of tigecycline sclerotherapy to treat recurrent pseudotumor after revision THA and no recurrence after 24-mo follow-up.
CONCLUSIONS: Tigecycline sclerotherapy is safe and effective in the management of recurrent pseudotumor after revision non-MoM THA in ALVAL cases.

BACKGROUND: Hemophilic pseudotumor (HPT)-related fracture is a rare but severe complication in patients with HPTs. These fractures often occur in femurs. There is no consensus on the standard surgical protocol for HPT-related femoral fracture. The present retrospective study evaluated the outcomes of these patients treated with surgical interventions.
METHODS: Ten patients with HPT-related femoral fractures who were treated with 14 surgical procedures due to 11 fractures in our hospital from January 2014 to April 2020 were evaluated retrospectively. Demographic data, fracture location, complications after surgery, and follow-up outcomes were recorded and analyzed. The mean follow-up period was 39.7 months.
RESULTS: The mean age at surgery was 31 years. Closed reduction external fixation (CREF) was originally performed in 2 patients, open reduction internal fixation (ORIF) was performed in 4 patients, screw fixation alone was performed in 1 patient, brace immobilization was performed in 1 patient, and amputation was performed in 3 patients. Bone union was observed in 5 patients, and an adequate callus was visible in 2 patients. Both patients with CREF had pin infections. Nonunion combined with external fixation (EF) failure occurred in 1 patient, and the plate was broken after ORIF. Three patients underwent autogenous or allogeneic cortical strut grafting. Three patients had HPT recurrence.
CONCLUSIONS: It is necessary to perform surgery in patients with HPT-related femoral fractures. Surgical treatments must consider fracture stabilization and HPT resection. Internal fixation is preferable, and EF should only be used for temporary fixation. If the HPT erodes more than one third of the bone diameter, strut grafts are necessary for mechanical stability. Amputation is an appropriate curative method in certain situations.

Pseudotumor is a rare complication following total hip arthroplasty (THA) with ceramic-on-metal (CoM) bearings. There is still in controversy about the using of CoM bearings when conducting surgery. We reported a case of a 47-year-old woman who underwent cementless CoM bearing THA because of left Crowe type III dislocation of the hip (DDH) in December 2009. One year after THA, she presented at our hospital complaining of crunching noise, pain, and decreased level of function. A revision surgery was performed because of left hip instability in December 2010, we adjusted the excessive anteversion of stem and replaced the head by using the long-neck ceramic head. In February 2019, she was admitted to our hospital complaining of repeated dislocation and fracture of greater trochanter. During the re-revision surgery, a pseudotumor and grey synovial sac were revealed. The metal liner was replaced with a ceramic liner and the greater trochanter was reattached using the Cable-Ready system. Clinical outcome was successful at 6 months postoperatively. This case vividly demonstrated CoM bearing should be avoided in THA. The pseudotumor highly destructed the periprosthetic soft tissues and the bone, which leaded to dislocation and periprosthetic fracture. The surgeon should be aware of the complication so that prompt diagnosis and treatment can be performed.

OBJECTIVE: Haemophilic pseudotumor (HPT) is a rare but challenging complication of haemophilia. This study was intended to provide our experience about clinical characteristics and surgical treatment of HPT.
METHODS: Clinical medical records were retrieved from the Hemophilia Center, Nanfang Hospital, to identify the patients who had been surgically treated from 1 January 2006 to 31 December 2017 with a definite diagnosis of HPT. Their clinical features, surgical management, outcomes and complications after surgery were analysed.
RESULTS: We identified 34 patients with HPT who had surgical treatment over a 12-year period and five of them had multiple HPTs. The incidence of HPT at this centre was 2.3% over the dozen years. A previous trauma leading to the development of HPT was reported in 18 cases (52.9%). The HPT affected only soft tissue in 7 patients, bone and soft tissue in 25 ones and joint in 2 ones. Preoperative infection and fistula formation happened in ten patients, two of whom were related to abdominal HPTs. Enterococcus faecalis was cultured in five cases with fistula formation. HPT associated with pathological fracture was observed in five cases, two of whom were treated by external fixation and 3 by HPT resection and metallic internal fixation. Amputation was performed for nine patients, 6 of whom had preoperative infection and fistula formation. Their follow-up duration averaged 4.2 ± 2.9 years (range, from 1 to 13.5 years) after surgery. Of all our cases, three suffered from postoperative infection, five from recurrence of HPT and two with external fixation from fracture non-union.
CONCLUSIONS: HPT patients with preoperative infection had worse prognosis than those without. Surgical treatment plus intensive replacement therapy was effective for HPT but with a high rate of complications. HPT resection and metallic internal fixation rather than external fixation should be recommended for HPT patients with pathological fracture.

BACKGROUND: Head breakage is a serious complication following total hip arthroplasty when using Ceramic on Ceramic bearings surfaces. There is still in controversy about the selection of bearing surfaces when conducting revision surgery.
METHODS: We describe the case of a fifty-year-old man who had undergone right total hip arthroplasty (THA) with ceramic-on-ceramic prostheses in 2011. After a fall 6 years after the primary procedures, radiographs suggested a ceramic head breakage for revision THA with exchange of metal-on-polyethylene bearing. However, 8 months later, severe metallosis and multiple pseudotumor was confirmed in pelvis and surrounding hip after re-revision THA with ceramic-on-polyethylene prostheses. Analysis of the serum metal ion indicated massive wear of the metal head and erosion of the stem neck and taper.
CONCLUSIONS: This case vividly demonstrates metal bearings should be avoided and revision with complete synovectomy and thorough debridement should be performed whenever possible for a fractured ceramic bearing.

OBJECTIVE: To compare mid-term clinical results of total hip arthroplasty (THA) with metal-on-metal (MoM) and metal-on-polyethylene (MoP) bearings and to evaluate the biological safety of the two kinds of prostheses.
METHODS: Thirty-two patients who received a primary THA with an MoM articulation between January 2008 and December 2010 were selected to form the MoM group retrospectively. The MoP group consisted of 32 patients who received a THA with an MoP prosthesis during the same period. Clinical assessments, imaging examinations, laboratory tests, and metal ion concentration detections were conducted on each patient. Another 32 healthy volunteers were recruited as the control group.
RESULTS: Twenty-seven patients in the MoM group and 28 patients in the MoP group completed the follow-up, with a mean follow-up time of 74.6 and 75.9 months, respectively. The mean Harris score at the latest follow-up was 91.5 ± 5.1 in the MoM group versus 88.9 ± 4.0 in the MoP group (P = 0.22). The MoM group showed a better range of motion in flexion, abduction, and external rotation. Co and Cr levels in the MoM group were 2.5-fold and 2.0-fold of these in the MoP group. A mild change of liver function was observed in both groups, while the values of renal function and humoral immunity stayed static. Elevated proportions of Th1 and Th17 cells and decreased proportion of Th2 cells were observed in the MoM group. The occurrence rate of pseudotumors in the MoM and MoP groups was 40.74% ± 9.45% and 14.28% ± 6.61%, respectively (P < 0.05).
CONCLUSIONS: At the mid-term follow-up, clinical results were satisfied in both groups. MoM prosthesis could result in elevated serum metal ion levels and there is a higher risk of pseudotumor. Long follow-up is needed to evaluate the safety of MoM prostheses.

OBJECTIVE: Hemophilic pseudotumors result from repeated episodes of bleeding into bone, subperiosteum, and soft tissue. Since clotting factors became available, uncontrolled perioperative bleeding is a less significant problem for surgeons in developed countries. However, they are more difficult to come by in China. Additionally, patients often have to undergo surgery for giant masses and suffer complications. We wanted to present our experience in the surgical management of hemophilic pseudotumors over a 40-year period.
METHODS: We retrospectively reviewed 429 hemorrhagic coagulopathy patients between 1983 and 2015. Diagnosis of hemophilic pseudotumor was confirmed following clinical, radiological, and pathological criteria. The data were recorded and analyzed: type and severity of hemophilia, presence of inhibitor, etiological antecedent, localization of pseudotumors, clinical signs, surgical management and outcomes.
RESULTS: Eighteen pseudotumor patients underwent surgical treatment. All of them were male, with mean age of 34.3 years. Fifteen patients had hemophilia A and three patients had hemophilia B. There were twelve proximal and two distal pseudotumor patients. The mean follow-up was 51.9 months. For pseudotumors in the extremities, complete surgical resection was achieved. For four patients with pelvic or abdominal pseudotumors, complete surgical resection was only achieved in two patients because of preventing potential vital organs injuries. Delayed healing of the incision, allergic reactions, and ureteral injury were the major complications.
CONCLUSIONS: Surgery is an alternative method with safety and efficacy. Careful and individual treatment is required by the hematologist, orthopedic surgeon and other members of the team who collaborate and participate in hemophilic surgery.

BACKGROUND: IgG4-related disease was first reported in 2001 and was officially named in 2010. It is now considered as a systemic disease that might affect any organ system. The characteristic pathological changes of IgG4-related disease are extensive infiltration of IgG4-positive plasma cells. IgG4-related disease is a kind of benign lesions, but there has not been well-defined standard treatment so far. Patients usually respond well to corticosteroids. The prognosis of IgG4-related disease is perhaps good as long as early detection and treatment.
METHODS: We report one case of IgG4-related disease with a 16-years anamnesis with multi-pseudotumor masses. He was diagnosed with chronic kidney disease with wide interstitial renal fibrosis. And he received glucocorticoids therapy. After 2 month therapy, the serum creatinine, erythrocyte sedimentation rate, and serum IgG4 decreased significantly. The discussion includes presentation, clinical course, diagnosis, and prognosis of IgG4-related disease. The case and discussion highlight the importance of diagnosis and the good prognosis of IgG4-related diseases.
RESULTS: Our case highlights the importance of diagnosis and the good prognosis of IgG4-related diseases. IgG4-related disease is a systemic fibro-inflammatory immune-mediated disorder and now recognized in almost every major organs. Characteristics of the disease is multiple lymph nodes and the response to glucocorticoids therapy is well. In such case, he had a history of 16 years with multi-pseudotumor masses and misdiagnosed for 16 years, if the doctors were not awareness of higher serum immunoglobulin G4 (IgG4) than normal, the correct diagnosis may be missed or delayed. Consequently, appropriate treatment for IgG4-related disease would also be delayed or not provided and likely result in increased morbidity and mortality.
CONCLUSIONS: IgG4-related disease is a systemic fibro-inflammatory immune-mediated disorder and progresses slowly. In the present patient the course of IgG4-related disease appears to be benign. The prognosis of IgG4-related disease depend on early diagnosis and treatment.

OBJECTIVE: To describe the clinical manifestations and types of, and our surgical experience with, neoplasms in the region of the temporomandibular joint (TMJ) in pediatric patients.
METHODS: From September 1997 to December 2013, a total of 18 patients with neoplasms in the region of the TMJ were treated at our department. They all underwent open surgeries. The clinical manifestations and radiological aspects of all the patients were reviewed. The average follow-up period was 61.8 months with a range of 12-221 months. We reviewed the history, physical examination, images, and related radiological examinations.
RESULTS: Of the 18 patients, 14 had benign tumors or pseudotumors, and four had malignant tumors. The ratio of pseudotumor to benign tumor to malignant tumor was 2.5:1:1. Limitations of mouth opening were more likely to occur with malignant tumors, and facial deformity had a higher incidence in benign tumors. Local resection was the first choice for patients with benign tumors or pseudotumors. All patients with malignant tumors underwent whole-tumor resection along the boundary, including the joint capsule, disc, and part of the temporal bone and mandible. During the follow-up period, no tumor reformation or new deformity was detected.
CONCLUSIONS: In the diagnosis of masses in the TMJ region, CT and MRI play an important role. Surgical removal of the mass with/without joint attachment was sufficient to treat benign and malignant tumors.