Naoto Oebisu

Overexpression of hexokinase-2 in giant cell tumor of bone is associated with false positive in bone tumor on FDG-PET/CT.

IntroductionThe aim of the current study was to evaluate the usefulness of maximum standardized uptake value (SUVmax) in 2-deoxy-2-F18-fluoro-d-glucose positron emission tomography combined with computed tomography (18F-FDG-PET/CT) for preoperative differential diagnosis between benign and malignant bone tumors.Materials and methodsSeventy-nine patients with bone tumors were examined by FDG-PET prior to histopathological diagnosis. The SUVmax was calculated and compared between benign and malignant lesions, and among different histopathological subgroups, to identify false-positive histological subtypes.ResultsThere was a statistically significant difference in the SUVmax of benign (3.7xa0±xa03.3; nxa0=xa017) and malignant (5.3xa0±xa03.3; nxa0=xa062) bone tumors. However, receiver operating characteristic curve analysis revealed the poor accuracy of this distinction. The cut-off value was determined to be 2.6, while the value of sensitivity and specificity was calculated to be 74.2 and 64.7xa0%, respectively. Giant cell tumor of bone (9.0xa0±xa02.0; nxa0=xa05) displayed a higher SUVmax than osteosarcoma (4.2xa0±xa02.3; nxa0=xa018). Immunohistochemical analysis demonstrated that markers of these cancers, hexokinase-2 (HK-2) and glucose transporter type 1 (GLUT-1), supported our findings.ConclusionThe poor accuracy of SUVmax in 18F-FDG-PET/CT in distinguishing malignant from benign bone tumors was confirmed; some benign bone tumors showed high FDG uptake. Giant cell tumor of bone was a major false-positive histopathological subtype of bone tumors, showing high FDG accumulation. HK-2 contributed significantly to FDG uptake, whereas GLUT-1 appeared to play no role in FDG uptake in giant cell tumor of bone.

Contrast-enhanced color Doppler ultrasonography increases diagnostic accuracy for soft tissue tumors

Resolution of ultrasonography (US) has undergone marked development. Additionally, a new-generation contrast medium (Sonazoid) used for US is newly available. Contrast-enhanced US has been widely used for evaluating several types of cancer. In the present study, we evaluated the ability of color Doppler US (CDUS) and Sonazoid to differentiate between benign and malignant soft tissue tumors. A total of 180 patients (87 male, 93 female) were enrolled in the present study. The patient ages ranged from 1 to 91 years (mean 58.1±20.0xa0years). The maximum size, depth, tumor margins, shape, echogenicity and textural pattern were measured on gray-scale images. CDUS was used to evaluate the intratumoral blood flow with and without Sonazoid. Peak systolic flow velocity (Vp), mean flow velocity (Vm), resistivity index (RI) and pulsatility index (PI) of each detected intratumoral artery were automatically calculated with power Doppler US (PDUS). The present study included 118 benign and 62 malignant tumors. Statistical significances were found in size, depth, tumor margin and textural pattern but not in shape or echogenicity on gray-scale images. Before Sonazoid injection, CDUS findings showed 55% sensitivity, 77% specificity and 69% accuracy, whereas contrast-enhanced CDUS showed 87% sensitivity, 68% specificity and 74% accuracy. There were no statistically significant differences between malignant and benign tumors regarding the mean Vp, Vm, RI and PI values determined on PDUS. In conclusion, contrast-enhanced CDUS proved to be a reliable diagnostic tool for detecting malignant potential in soft tissue tumors.

A ganglion within the ulnar nerve and communication with the distal radioulnar joint via an articular branch: case report.

An intraneural ganglion is rare, and involvement of an articular nerve may suggest a possible pathogenesis. We report an intraneural ganglion of the ulnar nerve with a connection to the distal radioulnar joint via the articular branch. We excised the ganglion, the stalk, and the articular branch. To date, there has been no recurrence.

Role of FDG-PET/CT for monitoring soft tissue tumors

The aim of the current study was to evaluate the limitations of 2-deoxy-2-F18-fluoro-D-glucose positron emission tomography combined with computed tomography (FDG-PET/CT) when monitoring soft tissue tumors. The diagnostic criteria of malignancy was defined as the tumor having a maximum standardized uptake value (SUVmax) ≥2.0 and a maximum diameter ≥5 cm as measured using FDG-PET/CT. One-hundred-and-thirteen patients, that were either included in the criteria or not, were compared. In addition, the values of SUVmax of the primary tumor and relapse in 12 patients were evaluated. The Kaplan-Meier analysis demonstrated that patients with tumors measuring ≥5 cm size and ≥2.0 SUVmax were associated with a worse survival rate. Among the 12 patients with relapse, statistical significances were detected in the tumor diameters, however, not in the SUVmax values. Thus, the criteria identified patients that were associated with a poor prognosis, and the SUVmax of distant metastases and local recurrences were identified to be significantly affected by tumor size.

A Comparative Study of Clinicopathological Features Between Simple Bone Cysts of the Calcaneus and the Long Bone

Background: The potential unrevealed clinicopathological differences between simple bone cysts situated in the calcaneus (calcaneal bone cysts) and those situated in long bones (long bone cysts) were investigated in the present study. Methods: A total of 41 cysts from 41 patients who underwent operative treatment were evaluated: 16 cysts in the calcaneus, 17 in the humerus, 7 in the femur, and 1 in the tibia. The clinical course, radiological findings, and histological features were retrospectively reviewed. Results: The mean patient age was 11.5 years (range, 3 to 25 years), and the mean follow-up was 33.0 months (range, 12 to 77 months). The mean patient age was significantly higher in patients with calcaneal bone cysts (13.5 years; long bone cysts, 10.2 years, P < .05). No treatment failure was seen for patients with calcaneal bone cysts, while 7 long bone cysts required reoperation. In H&E-stained specimens of the cyst wall, cholesterol clefts were identified in 10 of the 16 calcaneal bone cysts (62.5%), whereas none were identified in long bone cysts (0%; P < .0001). Conclusion: Our study elucidates the different clinicopathological features existing between calcaneal bone cysts and long bone cysts. Cholesterol clefting is most likely due to hemorrhaging and the subsequent breakdown of blood in the cyst. The significance of these differences between long bone and calcaneal cysts is still open to conjecture. Level of Evidence: Level III, retrospective comparative series.

Intraosseous schwannoma of the proximal femur

A schwannoma is a benign nerve sheath tumor commonly located in soft tissue. An intraosseous schwannoma is very rare, and only four cases involving the femur were found in a review of the English‐language medical literature. We present a rare case of a schwannoma with well‐defined, lytic, dumbbell‐shaped and benign‐appearing lesions of the proximal femur.

A case of dedifferentiated liposarcoma showing a biphasic pattern on 2-deoxy-2-F18- fluoro-D-glucose positron emission tomography/ computed tomography

Abstract Integrated 2-deoxy-2-F18-fluoro-D-glucose positron emission tomography combined with computed tomography (FDG-PET/CT) has been used in the field of soft tissue sarcoma. We report an 81-year-old man with dedifferentiated liposarcoma in the left thigh, which was composed of well-differentiated liposarcoma and pleomorphic malignant fibrous histiocytoma. As well as other radiological modalities, FDG-PET was able to demonstrate a biphasic signal pattern composed of well-differentiated liposarcoma and dedifferentiated area, being consistent with the histological grade of malignancy.

Solitary neurolymphomatosis of the brachial plexus mimicking benign nerve sheath tumour: case report.

Abstract Neurolymphomatosis typically appears as a diffuse lesion with thickening of the affected nerves on magnetic resonance imaging (MRI). MRI in the present case revealed a well-defined, solitary lesion showing continuity with brachial plexus nerves. Findings including clinical symptoms resembled benign nerve sheath tumour rather than neurolymphomatosis. Intra-operatively, the C8 root was focally swollen, corresponding to a well-circumscribed lesion on MRI. The diagnosis of neurolymphomatosis was obtained only after resection biopsy. Post-operatively, 18F-fluorodeoxyglucose positron emission tomography proved useful for follow-up evaluation. We offer the first description of the MRI characteristics of brachial plexopathy in neurolymphomatosis, along with the clinical course.

Reversed lateral upper arm flap with a vascularised fragment of the humerus for reconstruction of ulna shaft fracture after resection of malignant tumour: A case report

The lateral upper arm flap (LAF) is used for a pedicled flap with the vascular arcade at the elbow. There has been no report, however, with regard to the reverse lateral upper arm flap (R-LAF) with a vascularised humerus as an osteocutaneous flap. We describe the case of a 72-year-old woman with a fracture of the ulna after wide resection of a malignant tumour at the proximal half of the forearm, which was reconstructed with an R-LAF with a vascularised fragment of the distal humerus. The flap has successfully survived and the fracture was healed without any adverse event. The R-LAF with vascularised bone is a useful option for the simultaneous treatment of soft tissue and bone defects.

Clinical features of soft tissue sarcoma presenting intra-tumour haematoma: case series and review of the literature

IntroductionIntra-tumour haematoma is an uncommon clinical presentation in malignant soft tissue tumours. This study aimed to highlight the clinical features of patients with soft tissue sarcomas with intra-tumour haematoma.MethodsThe patient group was composed of eight men and one woman aged between 29 and 83xa0years (mean 44.0u2009±u200920.8). The average follow-up was 29.8xa0months. Clinical information, including clinical features, radiological information and treatment course, was retrospectively investigated.ResultsTumours were predominantly located in the chest wall and thigh, and average diameter was 10.3xa0cm. Six patients underwent needle biopsy with ultrasound sonography, and three underwent an open biopsy. Histological diagnoses indicated that all tumours were high grade, three of which were undifferentiated pleomorphic sarcomas, three synovial sarcomas, two pleomorphic liposarcomas, one a leiomyosarcoma and one a malignant peripheral nerve sheath tumour. The median diagnostic delay time was 3.0xa0months. Magnetic resonance imaging (MRI) indicated a haematoma area <25xa0% in three, 25–50xa0% in four and 50xa0% two. A wide resection was performed in eight patients, and radiotherapy was administered to one patient for the initial local treatment of a primary tumour. Local recurrence was detected in four patients, whilst five developed lung metastases. The five-year survival rate was 57.1xa0% and median survival 34.0xa0months.ConclusionsSoft tissue sarcomas with intra-tumour haematoma presented with locally aggressive and highly metastatic behavior, consistent with high-grade tumours.