Number of intra-operative cyclic knee motion required to achieve stable graft tension in anterior cruciate ligament reconstruction; a prospective clinical study.

BACKGROUND: Applying pretension by cyclic knee motion immediately before graft fixation in anterior cruciate ligament (ACL) reconstruction surgery decreases graft elongation during the postoperative course. However, the expected change in graft tension caused by cyclic knee motion remains unclear. We measured graft tension changes caused by cyclic knee motion during double-bundle ACL reconstruction. METHODS: We included 39 patients undergoing primary anatomical double-bundle ACL reconstruction with autologous hamstrings as graft sources, at multiple centers between February 2021 and August 2022. After securing the anteromedial (AM) and posterolateral (PL) bundle grafts to the femoral cortex, they were initially tensioned to 40 N per bundle. After 10 cycles of knee extension and flexion motion, ranging from 0 to 90-110°, tension was re-measured and re-tensioned to 40 N if the graft tension had decreased. This was repeated thrice for 10 cycles on each graft. Every 10 cycles, we recorded graft tension changes (ΔGT) and compared the mean ΔGT in the AM and PL bundles. Furthermore, we assessed relationships between total ΔGT in each bundle, age, sex, and graft diameter. RESULTS: Twenty-five women and 14 men with a mean age of 27.4 ± 12.4 years were included. The mean ΔGT in AM and PL bundles after every 10 cycles were 6.6 ± 3.7 N, 3.0 ± 2.3 N, 1.4 ± 1.5 N, and 9.9 ± 3.8 N, 4.9 ± 2.6 N, and 2.5 ± 1.9 N, respectively. There were significant differences in ΔGT in both bundles after every 10 cycles (p < 0.01). ΔGT in the AM bundle was significantly lower than in the PM bundle at the same number of cycles (p < 0.01). No correlation was observed between ΔGT in either bundle and age, sex, or graft diameter. CONCLUSIONS: The initially applied graft tension decreased by intra-operative cyclic knee movement, and the changes in graft tension decreased after retention and repeated cycles. Three sets of 10 cycles knee motion may avoid initial tension loss of the hamstring autograft in the early phase after double-bundle ACL reconstruction.

A refined method of en bloc open-door laminoplasty for resection of intradural spinal tumors in the thoracic and lumbar spine.

BACKGROUND: The open-door laminoplasty has been used to treat cervical spondylotic myelopathy. This technique has been applied to the surgical treatment of thoracic and lumbar spinal canal tumors instead of simple laminectomy or hemilaminectomy. However, previously reported laminoplasty methods did not keep posterior supporting elements intact such as the laminae and the spinous processes with supraspinous and interspinous ligaments, and almost all of them needed instruments for the fixation of reconstructed laminae. The purpose of this paper is to introduce our open-door laminoplasty method, which keep all posterior supporting elements intact and reconstruct the laminae without instrument. METHODS: Eight patients (mean age 61 years) underwent en bloc open-door laminoplasty in the thoracic and lumbar spine for resection of intradural spinal tumors. Two grooves are made bilaterally on the laminae just medial side of the facet joints. One-half of each spinous process of the adjacent vertebrae above and below the laminoplasty is cracked diagonally to create a green stick fracture and bent to the hinged side for sufficient elevation of the laminar flap. After tumor resection, the laminar flap is restored to its original site, resulting in the complete preservation of the posterior supporting elements. RESULTS: Operative exposure was good and permitted complete resection. No complications such as postoperative spinal canal stenosis or kyphosis were observed. Computed tomography(CT) indicated that bony fusion occurred in all cases. CONCLUSION: The supraspinous and interspinous ligaments above and below laminoplasty were kept intact during surgery in our method. Therefore, the continuity of posterior supporting elements (laminae and spinous processes connected by supraspinous and interspinous ligaments) were completely preserved.

Randomized comparative study of suspension femoral fixation device in graft position maintenance in anterior cruciate ligament reconstruction: EndoButton CL vs TightRope RT.

BACKGROUND: In double-bundle anterior cruciate ligament reconstruction (ACLR), fixed-loop and adjustable-loop cortical suspensory devices are commonly used to fix the soft graft on the femoral side. However, few studies have compared in vivo elongation of the two devices. The purpose of this study was to determine whether EndoButton CL (EB) and TightRope RT (TR), the suspensory fixation devices used in ACLR, maintained their length in vivo from the time of surgery through the postoperative period in a randomized controlled trial. METHODS: This study prospectively incorporated 30 patients undergoing initial ACLR at a single center. Participants were divided into two groups using a stratified randomization method with age and sex as assignment adjustment factors. EB or TR was used for fixation of the soft graft on the femoral side. The primary endpoint was to compare the elongation distance of the suspensory device. MRIs were taken within seven days after ACLR and 3,6,12 months postoperatively and measured by a radiologist in a blinded fashion. Secondary endpoints included the side-to-side difference in anterior translation, one leg hop test (HOP index), Lachman test, lateral pivot shift test, and Lysholm score one year postoperatively. RESULTS: Twenty-eight patients (EB, n = 13; TR, n = 15) were followed for one year. There was no significant difference between EB and TR groups in elongation from the immediate postoperative period to 3, 6, 12 months after surgery. However, the non-inferiority of TR to EB (non-inferiority margin: 1.5 mm) was not proved by the difference in measured elongation between the two groups (TR - EB, lower 95% CI. AM: 1.80 mm; PL: 1.86 mm) at 6 months. There was no significant difference in anterior translation, HOP index, Lachman test, lateral pivot shift test, or Lysholm score. CONCLUSION: EB and TR had similar graft retaining ability in vivo for 12 months, but the non-inferiority of TR against EB was not verified statistically.

Multiple Osteochondritis Dissecans in Multiple Joints.

BACKGROUND: Osteochondritis dissecans (OCD) rarely occurs in multiple joints. Furthermore, the existence of left-right asymmetric OCDs in different joints of the contralateral side of the body and lesions occurring with a temporal difference is rare. Here, we report a rare case with multiple OCDs sequentially detected in various joints. Case Presentation. The 15-year-old male patient was referred to our hospital for an OCD in the medial femoral condyle of the left knee. He had a history of an OCD in his right elbow, and his father had a history of surgically treated OCDs in both knees. One year and five months after, surgery was performed to the lesion in his left medial femoral condyle, a new OCD lesion occurred in the femoral trochlea of the same knee, which was again treated surgically. Five months after the second surgery, the patient returned with pain in the right knee, and an OCD on the right femoral trochlea was detected by an MRI scan. This lesion remained stable without any further restriction in physical activities for 17 months until detachment occurred and was again treated surgically. CONCLUSION: In cases with history and a family history of multiple OCDs, in particular, with a short stature, an MRI scan should be performed for the symptomatic joint to detect and treat the lesion before progression.

In vivo kinematics of cruciate-retaining total knee arthroplasty after a change of polyethylene insert configuration.

BACKGROUND: To investigate in vivo kinematics of total knee arthroplasty (TKA) with the introduction of a mildly constrained (MC) type of polyethylene (PE). We compared the knee kinematics with a reported pattern after surgery using the same component with a conventionally constrained (CC) type of PE. METHODS: Finite element analysis (FEA) was performed to examine different peak stress distribution of both types of PE. For in vivo study, patients who underwent cruciate-retaining TKA using a total knee system with MC-PE were included. Fluoroscopic surveillance was used to measure the weight-bearing deep knee bend (squatting) using a two-dimensional/three-dimensional (2-D/3-D) registration technique. RESULTS: FEA analysis revealed the edge loading of the femoral component on PE in CC but not in MC. During the study period, 42 patients underwent TKA with MC-PE. Among them, 13 agreed to participate in the present study. In vivo kinematics analysis found that starting from an average external rotation of femur being 7.1° at 0° of flexion, the rotation slightly decreased to 6.8° at 10° of flexion, then increased with increasing knee flexion until it reached 10.8° at 80° of flexion, and finally decreased to 9.8° at 100° of knee flexion. The results indicate a modest medial pivot pattern. Although the overall pattern was similar for both MC-PE and CC-PE, a slight difference was observed. MC-PE showed a slight internal rotation of 0.3° from 0 to 10° of knee flexion, whereas CC-PE showed a gradual increase of external rotation in this range. CONCLUSIONS: Change of configuration from CC to MC did not substantially affect in vivo kinematics of knees after TKA. Considering the theoretical wider range of allowance of rotation, MC-PE is easier for knee surgeons to use.

Timing of Intra-Articular Injection of Synovial Mesenchymal Stem Cells Affects Cartilage Restoration in a Partial Thickness Cartilage Defect Model in Rats.

OBJECTIVE: We investigated the effect of administration of intra-articular mesenchymal stem cells (MSCs) on cartilage repair at different timings, and the distribution of MSCs in the knee. DESIGN: A partial thickness cartilage defect (PTCD) was created on the medial femoral condyle in 14-week-old Sprague-Dawley rats. Intra-articular injection of 1 × 106 MSCs was performed at 3 time points, namely at the time of surgery (0w group), at 1 week after surgery (1w group), and at 2 weeks after surgery (2w group). For the control, 50 µL phosphate-buffered saline was injected at the time of surgery. The femoral condyles were collected at 6 weeks after creation of PTCD and assessed histologically. To investigate the distribution of MSCs, fluorescent-labeled MSCs were injected into the knee joint. RESULTS: In the control group, the cartilage lesion was distinguishable from surrounding cartilage. In the 0w group, hypocellularity and a slight decrease in safranin O stainability were observed around the injured area, but cartilage was restored to a nearly normal condition. In contrast, in the 1w and 2w groups, the cartilage surface was irregular and safranin O stainability in the injured and surrounding areas was poor. Histological score in the 0w group was significantly better than in the control, 1w, and 2w groups. At 1 day postinjection, fluorescent-labeled MSCs were mostly distributed in synovium. However, no migration into the PTCD was observed. CONCLUSIONS: Early intra-articular injection of MSCs was effective in enhancing cartilage healing in a rat PTCD model. Injected MSCs were distributed in synovium, not in cartilage surrounding the PTCD.

Age-dependent differences in response to partial-thickness cartilage defects in a rat model as a measure to evaluate the efficacy of interventions for cartilage repair.

The objectives of this study are (1) to examine age-dependent longitudinal differences in histological responses after creation of partial-thickness articular cartilage defects (PTCDs) in rats and to use this model (2) to objectively evaluate the effectiveness of interventions for cartilage repair. Linear PTCDs were created at a depth of 100 µm in the weight-bearing region of the medial femoral condyle in rats of different ages (3 weeks, 6 weeks, 10 weeks and 14 weeks). One day, one week, two weeks, four weeks and twelve weeks after PTCD generation, spontaneous healing was evaluated histologically and immunohistochemically. Effects of interventions comprising mesenchymal stem cells (MSCs) or platelet-rich plasma (PRP) or both on 14-week-old PTCD rats were evaluated and compared with natural courses in rats of other ages. Younger rats exhibited better cartilage repair. Cartilage in 3-week-old and 6-week-old rats exhibited nearly normal restoration after 4-12 weeks. Cartilage in 14-week-old rats deteriorated over time and early signs of cartilage degeneration were observed. With injection of MCSs alone or MSCs + PRP, 14-week-old PTCD rats showed almost the same reparative cartilage as 6-week-old rats. With injection of PRP, 14-week-old PTCD rats showed almost the same reparative cartilage as 10-week-old rats. This model will be of great use to objectively compare the effects of interventions for small cartilage lesions and may help to advance the development of disease-modifying osteoarthritis drugs.

Comparison of meniscal extrusion and osteophyte formation at the intercondylar notch as a predictive biomarker for incidence of knee osteoarthritis-Data from the Osteoarthritis Initiative.

BACKGROUND: Medial meniscal extrusion (ME) is a biomarker to predict later development of knee osteoarthritis (KOA). On the other hand, we have reported osteophyte formation at the posterior condylar notch of the femur served as a biomarker for the same purpose. The purpose of this study is to compare capacity of the two biomarkers in predicting KOA development. METHODS: Two cohort of knees were established utilizing publicly available data from the Osteoarthritis Initiative (OAI). No OA group (NOA) consisted of knees that were grade 0 or 1 on Kellgren and Lawrence grade (K/L) both at baseline and 48 months later, and pre-radiographic-OA group (PROA) consisted of knees that were grade 0 or 1 at baseline but grade ≥2 48 months later. Baseline MR images were evaluated in terms of ME and osteophyte formation at the posterior condylar notch. ME was evaluated both by meniscus subluxation index (MSI) indicating the ratio of the extruded width of the medial meniscus to the width of medial meniscal body and by the medial radial displacement (MRD) indicating actual extruded width. The size of the osteophyte was assessed using a semi-quantitative whole-organ magnetic resonance imaging score (WORMS). The predictive accuracy of KOA was assessed by the area under the receiver operating characteristic curve (AUC) and optimal cutoff was determined for each parameter. RESULTS: The AUC for MSI was 0.654 (0.561-0.748: 95% CI) and the cutoff value was determined as 17%. That for MRD was 0.677 (0.584-0.770) and the cutoff value was 2.2 mm. The AUC for the WORMS score at the posterior condylar notch was 0.667 (0.579-0.756) and the cutoff value was 2. CONCLUSIONS: Similar predicting capacity of KOA development was found both in ME and osteophyte formation at the posterior condylar notch. Using these simple parameter, mas-screening for KOA development would be possible.

Single vs. repeated matrix metalloproteinase-13 knockdown with intra-articular short interfering RNA administration in a murine osteoarthritis model.

Purpose: Our aims were 1) to estimate the duration of short interfering RNA (siRNA) effect on matrix metalloproteinase-13 (Mmp-13) levels by a single intra-articular injection using a mouse knee osteoarthritis (OA) model and 2) to test whether repeated injections results in any additional suppressive effect on cartilage degradation compared to a single injection. Materials and Methods: OA was induced in 9 weeks old male C57BL/6 mice by destabilization of medial meniscus (DMM). Chemically modified siRNA targeted for Mmp-13 was injected into the knee joint at 1 week post-DMM surgery. Control group of knees received that for non-targeted genes. Synovial tissue was collected to measure Mmp-13 expression levels by quantitative polymerase chain reaction (qPCR) at 2, 3, and 6 weeks after surgery in each group. To test the effect of multiple injections, we created four experiment groups according to the number of injections. Histological assessment of articular cartilage was performed at 8 weeks post-DMM surgery. Results: In the Mmp-13 siRNA-treated group, expression levels of Mmp-13 mRNA were decreased by 40% compared to the control group at 2 weeks after surgery (p = 0.04), before returning to baseline at 3 weeks after surgery. A significant improvement in the histological score was observed in all Mmp-13 siRNA-treated groups compared to the control group (p < 0.05). However, no significant differences were seen between the single and multiple injection group. Conclusions: Our results suggested that the duration of siRNA effect in the knee joint lasts for at least 1 week, and that no further benefit is achieved by multiple injections.

Evaluating different closed loop graft preparation technique for tibial suspensory fixation in ACL reconstruction using TightRope™.

In most anterior cruciate ligament (ACL) reconstructions, grafts are fixed to the femoral side first followed by the tibial side. Various techniques have been reported to achieve optimal tension on the grafts, but once the grafts are fixed it is difficult to adjust graft tension further. To enable post fixation tension control we have invented a new graft configuration using an adjustable loop-device (TightRopeTM, Arthrex, FL, USA) on the tibial side. In this paper, biomechanical properties of this configuration using soft tissue were examined in terms of graft diameter and various suture techniques (referred to as base suture) to make a closed circle to support TightRopeTM. Two experiments were conducted under different conditions. In each experiment, cyclic load, followed by a pull-to-failure load, was applied to the grafts and elongation and failure mode were recorded. (1) To evaluate the effects of diameter, 5.0 or 6.0 mm grafts were prepared by a single locking loop stitch as the base suture (SLL5, SLL6). (2) To evaluate different base sutures, 5.0 mm tendons were used, and grafts were prepared using five kinds of base sutures (SLL, ZLL: zigzag locking loop, DZLL: double zigzag locking loop, DK: double Krackow, DK w/o TR: double Krackow without TightRopeTM). In the first experiment, tearing was observed in 2 of 6 cases in the SLL5 test group, whereas no tearing was observed with SLL6. In the second experiment, no tearing was observed with DZLL or DK. Elongation was smaller in these two groups compared to the other groups. Mechanical strength decreases with a smaller graft diameter. Biomechanical properties differed with different base sutures and, among them, the double-zigzag-suture stitch and double Krackow provided less elongation and higher ultimate load in this graft configuration.

Simultaneous anterior and posterior screw fixations confined to the axis for stabilization of a 3-part fracture of the axis (odontoid, dens, and hangman fractures): report of 2 cases.

Fractures of the axis are considered to be one of the most common injuries to the cervical spine, accounting for more than 20% of all cervical spine fractures. Multiple fractures of the axis are much rarer, accounting for 1% of all cervical fractures. Management of such complex fractures is still challenging, and there is no strong consensus for the treatment. The authors describe the cases of 2 patients who presented with 3-part fractures of the axis consisting of an odontoid Type II fracture and a Levine-Edwards Type IA fracture, which were treated with concurrent insertion of an anterior odontoid screw and bilateral posterior pedicle screws. The cases presented were characterized by 1) a Type II odontoid fracture; 2) a Type IA traumatic spondylolisthesis with no or a little translation and angulation of C-2 on C-3 in a ring fracture of the axis; and 3) no disorders at the C2-3 disc on MR images. Therefore, the authors performed surgery confined to the axis by concurrently inserting an anterior odontoid screw and posterior bilateral pedicle screws without arthrodesis of C2-3. This was followed with cervical soft collar fixation for only 1-2 weeks. The outcomes were favorable, including good osteosynthesis, high primary stability, early patient mobilization, and preserved range of motion of the cervical spine at C2-3 as well as at C1-2.

[Clinical features of pneumothorax in patients with active nontuberculous mycobacterial lung disease].

UNLABELLED: This study was retrospectively conducted to clarify the clinical features of pneumothorax in patients with active nontuberculous mycobacterial (NTM) lung disease. The patients were 9 men and 7 women, with a median age of 70. Pathogenic mycobacteria were 12 Mycobacterium avium complex, 2 Mycobacterium kansasii, and 2 Mycobacterium fortuitum. More than one lung field was affected by NTM disease in 11 patients, whereas 4 patients were given a diagnosis of mild NTM disease only at the onset of pneumothorax. Five patients recovered with rest only, 4 with thoracic drainage, 4 needed surgery, and 2 developed chronic pneumothorax. Five patients experienced more than one recurrence of pneumothorax during treatment for NTM disease. The rate of the complication of pneumothorax in patients with NTM lung disease was estimated at around 2.3%. CONCLUSION: Pneumothorax associated with NTM lung disease is not rare and is sometimes difficult to control.

Efficacy of gefitinib for elderly patients with advanced non-small cell lung cancer harboring epidermal growth factor receptor gene mutations: a retrospective analysis.

OBJECTIVE: To retrospectively evaluate the efficacy and safety of gefitinib in elderly patients with advanced non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor mutations. METHODS AND PATIENTS: Nine patients aged 70 years or older who had advanced NSCLC with mutations of the epidermal growth factor receptor gene were treated with gefitinib, 250 mg daily. Clinical data, types of epidermal growth factor receptor mutations, efficacy and toxicity of gefitinib were evaluated in these patients. Tumor responses were assessed by computed tomography scan using the Response Evaluation Criteria in Solid Tumors. RESULTS: Six patients showed a partial response, and the other three exhibited stable disease. The overall response rate was 66.7%. The median progression-free survival was 396 days, whereas the median over all survival was 523 days. No serious toxicities were observed. CONCLUSION: Gefitinib is very efficacious and safe for elderly patients with adenocarcinoma of the lung harboring an EGFR tyrosine kinase mutation. The present data support the use of gefitinib in this particular subgroup.

[Trends in antibiotic susceptibility and genetic beta-lactam resistance patterns among Haemophilus influenzae cases isolated from adult patients with respiratory tract infection].

Haemophilus influenzae, a major respiratory tract pathogen, is becoming increasingly resistant to beta-lactam antibiotics. Studying annual trends in antibiotic susceptibility and genetic patterns of H. influenzae beta-lactam resistance, we isolated 122 strains from the adult respiratory tract in 2007, determined MIC for different antibiotics, and analyzed TEM-1 beta-lactamase resistant genes and ftsI encoding PBP3 mutation compared to results in 2005 and 2007. We found that ABPC-susceptible strains with MIC <1 microg/mL (BLNAS) accounted for 71.0%, ABPC-resistant strains with MIC exceeding 2 microg/mL without beta-lactamase activity (BLNAR) for 25.3%, and beta-lactamase-positive strains (BLP) for 3.7%. The BLNAS ratio showed no significant change from 2002 and 2005. The BLP ratio decreased from those in 2002 and 2005. Genetic studies of resistant genes showed that gBLNAS with no resistant genes had increased in the last five years. The ratio of all strains with PBP3 mutation (gBLNAR and gLow-BLNAR) remained constant from 2002 to 2007. The proportion of gBLNAR with two PBP3 mutations had increased, however, while gLow-BLNAR with one mutation had decreased. LVFX showed constant strong antimicrobial potency for all mutation groups. Among beta-lactam antibiotics, the lowest MIC90 was observed in parenteral CTRX and oral CDTR-PI use. Although a new MIC peak generated by gBLNAR became obvious in the ABPC and CDTR-PI MIC distribution, the MIC of the new peak was still low enough to treat with high doses of those two antibiotics.

[A case of Candida glabrata empyema].

A 72-year-old man was admitted to our hospital because of a low grade fever and malaise. He had received a middle to lower esophagectomy and proximal gastrectomy with reconstruction of a gastric conduit for esophageal cancer 12 years previously. Chest X-ray and CT scan revealed massive pleural effusion and consolidations on the right side. Candida glabrata was isolated 4 times from pleural fluid specimens. Candida antigen was negative in both serum and pleural effusion. However, while serum beta-D-glucan was negative, the level of beta-D-glucan in pleural effusion was extremely elevated. Thus, the patient was diagnosed as having C. glabrata empyema. He was treated with insertion of a thoracostomy tube followed by intrapleural instillation of amphotericin B and intravenous administration of micafungin. Pleural effusion was reduced and the repeated culture of the pleural effusion became negative after 27 days of treatment. Empyema with C. glabrata is rare and the present case is the second report of the disease in the Japanese literature.

[A case of pulmonary Mycobacterium avium infection presenting multiple nodules with substantial difference in 18F-fluorodeoxyglucose uptake].

A 56-year-old man presented with a chief complaint of chronic cough due to bronchial asthma and pulmonary emphysema in 2001, without any abnormal findings on chest CT. His symptoms improved with high-dose inhaled corticosteroid. In February 2004, multiple nodules without bronchiectasis appeared in the chest CT. Pulmonary Mycobacterium avium infection was diagnosed by bronchial lavage and sputum culture. After multiple nodules appeared and disappeared repeatedly without medication, most nodules vanished after administration of antituberculous drugs. In Feburary 2007, a rapidly growing mass appeared in the right upper lobe, and a new nodule emerged in the left upper lobe the following month. On 18F-fluorodeoxyglucose positron emission tomography (18 FDG-PET), a substantial difference in 18FDG uptake was observed although both lesions were shown to be caused by Mycobacterium avium infection by needle biopsy. The lung specimen of the lesion with high 18FDG uptake demonstrated neutrophil infiltrates, suggesting acute inflammation. On the other hand, neutrophil infiltrates were not observed in the lesion with low uptake. We conclude that the degree of 18FDG uptake is not useful to decide when to initiate therapy and evaluate the efficacy of treatment.

[Usefulness of monitoring plasma voriconazole concentration in patients with chronic necrotizing pulmonary aspergillosis].

We investigated the significance and the usefulness of monitoring plasma voriconazole levels in patients with chronic necrotizing pulmonary aspergillosis associated with underlying chronic respiratory diseases. The average trough level was 2.2 microg/ml and there was no correlation between trough levels and voriconazole doses. Orally administered drug showed no significant difference in trough or peak levels compared with parenteral injection. Six cases with visual adverse events had significantly higher nadirs compared to those without visual disturbance. All three cases who discontinued the drug due to liver dysfunction had plasma trough levels higher than 4.0 microg/ml. Those who failed to respond to the treatment had trough levels lower than 1.4 microg/ml or peak levels lower than 2.8 microg/ml, while some cases with plasma level lower than those levels responded well. Since plasma voriconazole level has a large inter-patient variability, drug monitoring may be beneficial to evaluate the drug efficacy and safety in each individual.

[A case of pulmonary tumor thrombotic microangiopathy associated with lung adenocarcinoma diagnosed by CT-guided lung biopsy].

A 46-year-old woman was admitted to our hospital because of bloody and chest pain. Chest X-ray and CT scan revealed a 17-mm nodule in the left upper lobe, consolidations in both lower lobes, and mediastinal and hilar lymphadenopathy. CT-guided lung biopsy from the right lower lobe revealed tumor cell embolism, intimal fibrocellular proliferation of small arteries, fibrin thrombi and recanalization. Embolic tumor cells were adenocarcinoma and immunohistologial staining for TTF-1 was positive. The patient was diagnosed as having pulmonary tumor thrombotic microangiopathy (PTTM) associated with clinical stage IV primary lung adenocarcinoma. Although chemotherapy with carboplatin and paclitaxel resulted in improvement of pulmonary consolidations, multiple bone metastatic lesions appeared. The patient was subsequently treated with docetaxel, and gemcitabine thereafter. This was the first reported case of PTTM associated with lung cancer and diagnosed antemortem by CT-guided biopsy. This suggests that CT-guided lung biopsy may be useful for diagnosis of PTTM, and enable establishment of appropriate cancer chemotherapy.