Kyoji Okada

Hirosaki University, Khirosaki, Aomori Prefecture, Japan

Are you Kyoji Okada?

Claim your profile

Publications (77)156.34 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patient: Male, 5 Final Diagnosis: Osteoblastoma Symptoms: - Medication: - Clinical Procedure: - Specialty: Oncology. Rare disease. Osteoblastomas are relatively uncommon bone tumors that account for <1% of all bone tumors. They usually occur in the medullary region of the bone. As such, intraarticular osteoblastomas are quite rare. In this report, we present the case of a 5-year-old boy who presented with vague pain and subluxation of the hip joint due to an intraarticular osteoblastoma. Radiological examinations showed an irregular calcified mass lesion in the hip joint. The final diagnosis of osteoblastoma was made by histological examination. The patient's symptoms completely subsided following surgical removal of the tumor. Osteoblastomas can occur in the intraarticular region. Although quite rare, osteoblastoma should be considered among the differential diagnoses for patients with pain and subluxation of the hip joint.
    The American journal of case reports. 01/2013; 14:258-62.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract Background and purpose. Giant cell tumor of bone (GCT) is sometimes difficult to distinguish from other giant-cell-rich tumors such as chondroblastoma (CHB) and aneurysmal bone cyst (ABC). The usefulness of p63 as a diagnostic marker for GCT is controversial. While there have been no reports about p63 as a prognostic marker for local recurrence, various p63-positive rates in GCT have been reported. The purpose of this study was to investigate retrospectively whether p63 is useful as a diagnostic marker and/or a prognostic marker for local recurrence of GCT. Methods. This study included 36 patients diagnosed with either GCT (n = 16), CHB (n = 9), ABC (n = 7), or non-ossifying fibroma (NOF) (n = 4). p63 immunostaining was performed for all specimens. The mean p63-positive rate was compared with the four diseases and between the recurrent and non-recurrent cases of GCT. Results. Although the mean p63-positive rate for GCT (36.3%) was statistically higher than that of all other diseases examined (CHB: 15.2%; ABC: 5.8%; NOF: 3.4%), p63 was not specific for GCT. The mean p63-positive rate for recurrent GCT cases (73.6%) was statistically higher than that for non-recurrent cases (29.1%). Conclusion. In the diagnosis of GCT, p63 is a useful but not a conclusive marker. However, p63 did appear to indicate the biological aggressiveness of GCT. Therefore, p63 may help surgeons to estimate the risk of recurrence after surgery and help them to choose the best treatment for each GCT case.
    Upsala journal of medical sciences 10/2012; · 0.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We present a rare case of osteosarcoma involving the patella. A 30-year-old Japanese woman first consulted our out-patient clinic with a 2-year history of knee pain. Radiographs showed an enlargement of the patella with irregular distribution of both osteolytic and sclerotic lesions. Computed tomography and magnetic resonance imaging demonstrated soft tissue extension at the anterior part of the patella. Incisional biopsy showed abundant osteoid formation by spindle-shaped malignant cells, and the histological diagnosis was conventional osteosarcoma. The patient underwent preoperative chemotherapy, but there was no response. Furthermore, she developed a pathological fracture during chemotherapy. She underwent above-the-knee amputation with postoperative chemotherapy. She developed multiple metastases in the thoracic vertebrae 20 months after the surgery. At the most recent examination, she remains alive with multiple spinal metastases without paralysis 4 years after the surgery.
    Upsala journal of medical sciences 12/2011; 117(3):342-6. · 0.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Giant cell tumor (GCT) of the small bones (small-bone GCT) is usually rare and considered somewhat different from conventional GCT. The purpose of this study was to investigate and report the clinicopathological features of 11 cases with small-bone GCT. Patient information was obtained with the help of questionnaires. X-rays and paraffin blocks obtained from several institutions were clinically, radiographically, and histologically evaluated. Small-bone GCT was observed in younger patients compared to conventional GCT; 5 of the 11 (45%) patients were below 20 years of age, whereas the corresponding figure for all GCT patients is 16% in Japan. Excessive cortical bone expansion is a special feature. There were two cases of recurrence and one case of lung metastasis; the primary lesion was in the hand for all three cases. In contrast, no primary lesion of the foot recurred or metastasized. Varying degrees of positive p63 immunostaining were observed in all examined cases (n = 9) of small-bone GCT but were negative in case of giant cell reparative granuloma (GCRG) and solid variant of aneurysmal bone cyst (ABC). One case that demonstrated high-intensity positive staining had two episodes of recurrence. Small-bone GCT tends to develop in younger patients than does conventional GCT. Primary GCTs of the hand may be biologically more aggressive than those of the feet. The p63 immunostaining may be useful not only for differential diagnosis but also for prognostication of small-bone GCT.
    Upsala journal of medical sciences 09/2011; 116(4):265-8. · 0.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dedifferentiated liposarcomas usually occur in the retroperitoneal space and relatively rarely in the extremities. We identified 18 patients with primary dedifferentiated liposarcoma in the extremities from the files of Tohoku Musculoskeletal Tumor Society and analyzed demographics, histologic findings, treatments and prognostic factors. The average follow-up period was 58 months. The subjects were 12 men and 6 women with a mean age of 65 years. All tumors were in the thigh. Nine patients noticed a rapid enlargement of the long-standing tumor. Histologic subtypes of the dedifferentiated area were undifferentiated pleomorphic sarcoma (n = 12), osteosarcoma (n = 2), rhabdomyosarcoma (n = 2), leiomyosarcoma (n = 1) and malignant peripheral nerve sheath tumor (n = 1). In the patient with rhabdomyosarcoma-like dedifferentiated area, extensive necrosis was observed after the preoperative chemotherapy. One patient who underwent marginal excision developed a local recurrence, but inadequate surgical margin was not associated with a risk of local recurrence. Three patients had lung metastasis at initial presentation, and four other patients developed lung metastases during the follow-up period. The overall survival rate was 61.1% at 5 years. On univariate analyses, large size of the dedifferentiated area (>8 cm), high MIB-1-labeling index (>30%) for the dedifferentiated area and lung metastasis at initial presentation were significantly associated with poor prognosis. Primary dedifferentiated liposarcoma in the extremities predominantly occurred in the thigh and a rapid enlargement of long-standing tumors was a characteristic symptom. Although the local behavior of these tumors was less aggressive than that of retroperitoneal dedifferentiated liposarcomas, they had a relatively high metastatic potential.
    Japanese Journal of Clinical Oncology 07/2011; 41(9):1094-100. · 1.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE: The purpose of this article is to present the route of extension in nine soft-tissue tumors and tumorlike lesions of the pelvic wall. CONCLUSION: Soft-tissue tumors of the pelvis, particularly malignant ones, extend into other compartments through specific pathways that are bordered by bones, ligaments, and fasciae. Such pathways include the greater sciatic foramen, the obturator foramen, the femoral canal, the muscular lacuna, the pelvic outlet, and the inguinal canal.
    American Journal of Roentgenology 03/2010; 194(3):746-53. · 2.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Pigmented villonodular synovitis (PVNS) is a benign, locally aggressive disease of the synovium; its cause remains unclear. The most frequently involved joint is the knee, followed by the hip, ankle, wrist, and shoulder. Pigmented villonodular synovitis of the elbow joint is rare. Synovectomy is currently believed to be the best treatment for PVNS. Open or arthroscopic synovectomy is usually selected. During synovectomy for PVNS, the possibility of local recurrence after surgery must be considered. The recurrence rate after synovectomy of any joint for PVNS is approximately 40%. Therefore, surgical treatment for PVNS of the elbow requires sufficient removal of the lesion. For good functional results, prevention of postoperative joint stiffness is also necessary. This article describes a case of a 29-year-old woman with PVNS of the right elbow who was treated by total synovectomy using the Tsuge technique. Tsuge reported a new surgical technique for debridement arthroplasty using a posterolateral approach to the elbow in 1987. He has also reported using this procedure during arthroplasty for posttraumatic stiff elbow and for synovectomy in rheumatoid arthritis. This approach permits easy dislocation of the elbow and provides a good view of the whole joint. Although the recurrence rate of PVNS of the elbow is high, our patient has retained good elbow function with no evidence of local recurrence at 30 months postoperatively.
    Orthopedics 02/2010; 33(2):122-4. · 1.05 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study describes a unique case of bilateral stress fractures of the fibulae and provides a literature review. A 16-year-old female badminton player presented with pain around the bilateral distal lateral legs. She had mild bilateral varus deformity at the knee joint, and the bilateral ankles showed valgus deformity in standing posture. Radiographs and computed tomography showed periosteal reactions on the bilateral distal fibulae. Technetium-99m bone scintigraphy demonstrated increased uptake in the bilateral distal fibulae and the bilateral middle third of the tibiae. A diagnosis of bilateral distal fibular stress fractures was made. She was advised to stop playing badminton until the symptoms disappeared. Varus deformity of the knee and valgus deformity of the ankle may have influenced the mechanism underlying bilateral symmetric stress fractures.
    Medical Principles and Practice 01/2010; 19(6):490-2. · 0.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This case report describes an enchondroma of the distal phalanx of the right little finger in a 37-year-old woman with Camurati-Engelmann disease. Curettage of the tumor and artificial bone grafting were performed in May 2004. Surgical treatment resulted in a good clinical outcome with no evidence of recurrence at 5-year follow-up. The genetic relationships between Camurati-Engelmann disease and benign chondroid tumors are discussed.
    Upsala journal of medical sciences 11/2009; 115(2):157-60. · 0.73 Impact Factor
  • Journal of Orthopaedic Science 11/2009; 14(6):826-9. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: High-intensity focused ultrasound (HIFU) therapy offers great promise for the treatment of cancer. The histological changes, including the antitumor immunological response, after HIFU treatment was examined in soft tissue sarcoma. Sarcoma 180 cells were injected subcutaneously in mice. Approximately 2 weeks after the injection, the tumor was irradiated by a single shot of HIFU. The tumor diameter was measured and the survival rate was observed after treatment. The tumors were resected, and stained with TUNEL stain, tartrate-resistant acid phosphatase (TRAP) stain to detect tumor-associated macrophages, and immunohistochemical stains for CD4 and CD8. The tumor size in the HIFU group was significantly smaller than the control and survival rate was significantly higher. The numbers of TUNEL-, TRAP-, CD4- and CD8-positive cells infiltrating the tumor were significantly higher in the HIFU group. HIFU, even when administered as a single shot, induces apoptosis of tumor cells and intratumoral infiltration of macrophages and lymphocytes.
    Anticancer research 10/2009; 29(10):3877-82. · 1.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Loose bodies in the spinal canal are extremely rare, with only two cases reported previously in the literature. To report a rare case of an osseous loose body in the cervical spine with radiographic evidence of dramatic enlargement of the loose body in the spinal canal over the course of 9 years. Case report. A 50-year-old man presented with progressive numbness and weakness of the upper and lower extremities and swaying gait in 2007. He had a history of temporary incomplete tetraplegia after a fall in 1998. Magnetic resonance imaging revealed enlargement of the posterior mass-occupying lesion compressing the cord at C5-C6 over the course of 9 years. Neurological examination with motor and sensory status. Posterior decompressive laminectomy was performed. An isolated, smooth-surfaced, bony, hard mass was found between the ligamentum flavum and facet joint and removed. Histological examination demonstrated trabecular bone and peripheral cartilage mixed with fibrous and fibrocartilaginous tissue. Clinical evaluation of the patient 6 months postoperatively showed total resolution of neurological symptoms. We report herein an extremely rare case of an osseous loose body in the spinal canal with cord compression. This report represents the first documented case of growth of a loose body in the spinal canal.
    The spine journal: official journal of the North American Spine Society 09/2009; 9(11):e11-4. · 2.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hibernoma is a rare adipose tissue tumor of the soft tissue and the term is derived from the histological similarities to the brown fat found in hibernating animals. It usually occurs in the interscapular area, back, and neck and a few cases have been reported in the buttock or thigh. Two cases are presented, one of which had a lesion in the buttock and the other a lesion in the thigh. The lesion in the buttock extended into the pelvis. CT and MR findings suggested liposarcoma in both cases, but the uptake was extremely intense on 18F-FDG-PET in one case. This was not typical of liposarcoma and suggestive of hibernoma. Biopsy specimens revealed a proliferation of adipose cells with vacuolated granular eosinophilic cytoplasm. No cellular atypia or mitotic figures were observed in either case. A marginal excision was performed in one case and an intralesional excision in the other. There were no signs of local recurrence at the final follow-up. While occurrences in the buttock or thigh are exceedingly rare, hibernoma should be included in the differential diagnosis of an adipose tissue tumor in the thigh, even though the imaging findings mimic liposarcoma. 18F-FDG-PET may be a very meaningful technique to differentiate hibernoma from liposarcoma. A correct diagnosis should be established to prevent over-surgery.
    Medical science monitor: international medical journal of experimental and clinical research 08/2009; 15(7):CS117-22. · 1.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sonodynamic therapy (SDT) is a promising methodology for cancer treatment. Methylene blue (MB) is a phenothiazine dye that is widely used in clinical practice and can be administered intravenously. The sonodynamic antitumor effect of 1, 10 and 100 microM MB on sarcoma180 (S180) cells was investigated in vitro. After ultrasound (US) exposure at 0.24 W/cm(2) for 30 seconds, survival rates of S180 cells in the presence of 10 and 100 microM MB were significantly lower than that of the control group. These effects were significantly inhibited by the addition of D-mannitol, but not by L-histidine or superoxide dismutase. Microvilli loss and blebbing on the surface of S180 cells were observed in the presence of 100 muM MB after US exposure. MB has a sonodynamic antitumor effect on S180 cells in vitro and the hydroxyl radical appears to be the principal mediator of this effect.
    Anticancer research 07/2009; 29(6):2411-5. · 1.71 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the treatment of grade 1 chondrosarcoma of long tubular bones, a wide excision with replacement by a metal prosthesis has been widely used. However, postoperative function of the affected extremity has occasionally been problematic. In two cases of grade 1 chondrosarcoma, a 54-year-old man with a lesion in the mid humerus and a 17-year-old woman with the lesion in the proximal femur, we performed curettage with pasteurization in situ. In both cases, destruction of the cortical bone was limited on radiographs. Follow-up studies 11 years after surgery did not showed local recurrence or functional deficit in either case. This less invasive surgical procedure has an advantage of sparing limb function and preventing local recurrence for grade 1 chondrosarcoma.
    Medical science monitor: international medical journal of experimental and clinical research 03/2009; 15(3):CS44-8. · 1.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this report, we present a 68-year-old man with rice body formation in the flexor tendon sheath of the fingers without any inflammatory diseases such as tuberculosis or rheumatoid arthritis. The patient visited our institute in March 2004 with a one-month history of swelling and pain of the right distal forearm. Laboratory data were within normal limits, and the rheumatoid factor was negative. He had no history of tuberculosis, and the tuberculin reaction was weakly positive. Magnetic resonance (MR) images showed a mass measuring 6 cm x 4 cm around the flexor tendons of the forearm. Many rice bodies had been erupted from a small hole of the fibrous wall of the mass at the time of incisional biopsy performed in June 2004. Histological diagnosis was synovitis with fibrous loose bodies. In July 2004, spontaneous ruptures of the right fourth and fifth flexor tendons occurred. Open repair was performed in August 2004. The patient regained good function of the operated fingers with no evidence of recurrence at the latest follow-up in March 2009.
    Upsala journal of medical sciences 02/2009; 114(3):184-8. · 0.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Sonodynamic therapy (SDT) is a promising methodology for cancer treatment. Lomefloxacin hydrochloride (LFLX) has been reported to have sonodymamic antitumor effects. We synthesized LFLX derivatives conjugated with methoxy polyethylene glycol (PEGylated LFLXs) and investigated their ultrasonically induced antitumor effects. After ultrasound exposure at 2.0 MHz for 30 s, the survival rates of Sarcoma 180 cells in the presence of lower molecular weight PEGylated LFLXs (200 microM) were significantly lower than those of the control and the LFLX at 1.5 and 2.0 W/cm2. This enhancement was significantly inhibited by the addition of L-histidine, but not by D-mannitol or superoxide dismutase. There was no apparent cell damage in the presence of high molecular weight PEGylated LFLX even at 3.0 W/cm2. These findings indicate that the sonodynamic antitumor effects of lower molecular weight PEGylated LFLXs are better than those of LFLX.
    Anticancer research 02/2009; 29(1):243-8. · 1.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We report a rare case of Langerhans cell histiocytosis involving the sternum. The patient was a 12-year-old girl presenting with anterior chest pain and swelling. Radiographs and computed tomography showed an osteolytic lesion in the sternum. Technetium bone scintigraphy revealed increased uptakes in the sternum, the greater trochanter of the right femur, and the right distal tibia. Incisional biopsy for the sternum lesion was performed, and the histopathologic diagnosis was Langerhans cell histiocytosis. She was treated with chemotherapy and the symptoms disappeared.
    Upsala journal of medical sciences 02/2009; 114(2):121-5. · 0.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to determine the elasticity of the coracoacromial ligament in shoulders with and without rotator cuff tears. The coracoacromial ligaments from 20 cadaveric shoulders (average patient age 79.5 years; 8 men, 12 women) were divided into six portions--three portions (acromial, central, and coracoid) in two layers (superficial and deep). A total of 120 samples were studied. First, the samples were classified by the collagen fiber orientation into three degeneration patterns: wavy, straight, irregular. For each pattern, the tissue sound speed, which shows a positive correlation with elasticity, was measured with scanning acoustic microscopy. Next, the samples were divided into three groups: 60 samples from shoulders with rotator cuff tears (RCT group), 30 samples from shoulders with an intact rotator cuff and a subacromial spur (spur group), and 30 samples from shoulders with an intact rotator cuff without a subacromial spur (control group). All shoulders with rotator cuff tears had subacromial spurs. The tissue sound speed and the histological findings were compared among the groups. The sound speeds in the wavy, straight, and irregular patterns were 1592 +/- 17.2 m/s (mean +/- SD), 1626 +/- 28.0 m/s, and 1607 +/- 29.8 m/s, respectively (P < 0.0001). The sound speed in the straight pattern was higher than that in the wavy pattern (P < 0.0001), and that in the irregular pattern was lower than that in the straight pattern (P = 0.0023). The RCT group and the spur group had more straight patterns (P = 0.0002) and fewer wavy patterns (P < 0.0001) than did the control group. Significant differences in the sound speed were observed between the groups (P < 0.0001): 1596 +/- 19.1 m/s in the control group, 1630 +/- 31.5 m/s in the spur group, 1612 +/- 28.6 m/s in the RCT group. The coracoacromial ligament in shoulders with rotator cuff tears shows higher elastic modulus than in age-matched normal shoulders due to degeneration of the ligament.
    Journal of Orthopaedic Science 01/2009; 14(1):62-7. · 0.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: It is possible to evaluate the size of rotator cuff tears by ultrasonography (US) or magnetic resonance imaging. However, there are only a few reports on the imaging assessment of the configuration of cuff tears, which could provide important preoperative information that assists performing an optimal anatomical repair. The purpose of this study was to determine quantitatively the reproducibility of three-dimensional US in the assessment of rotator cuff tear configuration. Ten embalmed cadaveric shoulders with rotator cuff tears were examined. After resecting the proximal humerus with the rotator cuff, we put it in water and scanned it using high-resolution US with a three-dimensional linear probe. Actual tear lengths and widths were compared with sonographic measurements (Pearson correlation coefficient). By superimposing the real photographic image on the reconstructed three-dimensional image, we calculated the concordance rate (ratio of the concordance area to the tear area). The actual tear length (16.6 +/- 7.1 mm; mean +/- SD) and width (8.4 +/- 4.4 mm) were correlated with the tear length (16.4 +/- 7.5 mm) and width (8.2 +/- 4.4 mm) measured from reconstructed three-dimensional ultrasonograms (r = 0.998 and 0.994, respectively). The mean concordance rate was 91.4%, indicating that almost exactly the same configuration was reconstructed by US. Three-dimensional US is useful for evaluating the configuration of rotator cuff tears. This is the first report to quantify the similarity between the configuration evaluated by US and the actual configuration. Using this method, we can visualize the configuration of rotator cuff tears preoperatively, facilitating optimal repair design.
    Journal of Orthopaedic Science 12/2008; 13(6):510-3. · 0.96 Impact Factor

Publication Stats

676 Citations
156.34 Total Impact Points

Institutions

  • 2011
    • Hirosaki University
      • Department of Orthopedic Surgery
      Khirosaki, Aomori Prefecture, Japan
  • 2004–2011
    • Akita University
      • Department of Orthopaedic Surgery
      Akita, Akita, Japan
  • 2002–2010
    • Iwate Medical University
      • • Department of Radiology
      • • Department of Orthopaedic Surgery
      Morioka, Iwate, Japan
  • 1994–2010
    • Akita University Hospital
      Akita, Akita, Japan
  • 2006
    • Numazu City Hospital
      Sizuoka, Shizuoka, Japan