Masachika Ikegami

Angiofibroma of soft tissue with fibrohistiocytic features and intratumor genetic heterogeneity of NCOA2 gene rearrangement revealed by chromogenic in situ hybridization: A case report

Angiofibroma of soft tissue is a recently described soft tissue tumor that is characterized by fibroblastic spindle tumor cells with arborizing capillary proliferation. Cytogenetically, it harbors a specific fusion gene involving the nuclear receptor coactivator 2 (NCOA2) gene. We report here additional new pathological and cytogenetic features. A soft tissue tumor in the left thigh of 73‐year‐old female was investigated. Microscopically, histiocytoid tumor cells were scattered in an edematous background with branching capillary proliferation. Immunohistochemically, we identified that the tumor cells were positive for histiocytic markers such as CD68 and CD163. Rearrangement of the NCOA2 gene was detected successfully by chromogenic in situ hybridization; however, abnormal signal patterns were observed in only a small subset of tumor cells. Unlike typical tumors with bland spindle cells, the present tumor needs to be distinguished from myxoid, dendritic and clear cell tumors. This case may suggest that angiofibroma of soft tissue is not in the center of the fibroblastic/myofibroblastic tumor group, but rather shows a fibrohistiocytic nature. We also found intratumor genetic heterogeneity, which is uncommon for a translocation‐associated tumor. Therefore, careful evaluation is required to detect the gene rearrangement in this tumor entity.

Prevalence and clinical outcomes of hip fractures and subchondral insufficiency fractures of the femoral head in patients with tumour-induced osteomalacia

PurposeTumour-induced osteomalacia (TIO) is a rare paraneoplastic syndrome usually caused by phosphaturic mesenchymal tumours, leading to great distress due to bone pain and affecting quality of life (QoL). This study aimed to investigate the prevalence and clinical outcomes of hip fractures and subchondral insufficiency fractures (SIF) of the femoral head.MethodsTwelve TIO patients were treated between January 2000 and December 2016 at our hospital. All underwent surgery for the tumour causing TIO, and complete removal of the tumour was accomplished in nine of 12 cases. Plain radiographs of the hip were obtained in all cases, and magnetic resonance imaging (MRI) was obtained from 15 hips representing eight patients before tumour removal. We evaluated the prevalence of hip fractures or SIF and their clinical outcomes.ResultsHip fractures were observed in six of 12 cases, and the total number of fractures was nine, of which five were femoral neck, two were intertrochanteric and two were subtrochanteric fractures. Conservative treatment, regardless of complete remission of TIO, was successful except in one case with impending subtrochanteric fracture. SIFs were observed in 11 of 24 hips. Seven of 11 hips with SIF showed progression after surgery for tumour resection.ConclusionsHip fractures and SIF are highly prevalent in TIO patients. Surgical and medical treatment for TIO is sufficient for treating hip fractures conservatively. However, SIF tends to show progression of femoral head collapse, serving as the main cause of pain after successful TIO treatment.

Multiple Acrometastases in a Patient with Renal Pelvic Urothelial Cancer

Metastasis may occur in any bone but more commonly occurs in the spine, pelvis, or other axial bones. Metastasis in peripheral bones located distal to the elbow or knee, so-called acrometastasis, is rare. Although the mechanism of acrometastasis development is not completely understood, it is thought to be the result of a massive dissemination of cancer cells; thus the prognosis of patients with acrometastasis is relatively poor. Here, we report the case of renal pelvic cancer with multiple acrometastases in both the upper and lower extremities without axial bone metastasis in a 68-year-old man. After two regimens of chemotherapy, he suffered from pain on his wrist and ankle and swelling and hemorrhage of his toe. He had no axial bone metastasis by CT but was diagnosed with multiple acrometastases by plain radiographs. Radiation therapy and disarticulation of the left big toe at the metacarpal-phalangeal joint were performed and his pain and hemorrhage were successfully controlled. Although acrometastasis from renal pelvic cancer is very rare, we should recognize that acrometastasis might occur which exists outside of the CT scanning field.

Recalcitrant Lateral Premalleolar Bursitis of the Ankle Associated with Lateral Ankle Instability

Lateral premalleolar bursitis of the ankle is a rarely reported disorder in the English literature although it is not uncommon in Asian countries where people commonly sit on their feet. Here, we present the case of a 66-year-old woman with recalcitrant lateral premalleolar bursitis associated with lateral ankle instability which was successfully treated with surgical resection of the bursa and repair of the anterior talofibular ligament. Operative findings revealed a communication between the bursa and articular cavity of the ankle joint via the sheath of the extensor digitorum longus tendon, which was considered to act as a check valve leading to a large and recalcitrant bursitis. This report provides a novel concept about the etiology of recalcitrant lateral premalleolar bursitis of the ankle.

FOSL1 immunohistochemistry clarifies the distinction between desmoplastic fibroblastoma and fibroma of tendon sheath.

Although desmoplastic fibroblastoma (DFB) and fibroma of tendon sheath (FTS) are well‐established entities, they may show overlapping clinicopathological features. In addition, cytogenetic data showing a shared 11q12 rearrangement in a small number of cases suggest a close link between these entities. A recent microarray study revealed up‐regulation of FOSL1 mRNA in DFBs with 11q12 rearrangement. The aim of this study was to clarify the relationship between DFB and FTS.

Secondary Chondrosarcoma Presenting with Symptoms Similar to Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is caused by heterogeneous factors that compress the brachial plexus and subclavian artery; tumor is rarely a cause of TOS. Here, we present the case of a 26-year-old man with secondary chondrosarcoma arising from osteochondroma of the left clavicle causing TOS, with a direct compression of the brachial plexus and subclavian artery. Immediately after surgery, the symptoms of TOS reduced. To our knowledge, this is the first case of a secondary chondrosarcoma of the clavicle causing TOS, which is possibly the key symptom for diagnosing malignant transformation of osteochondroma of the clavicle.

Lymphaticovenous Anastomoses for Lymphedema Complicated by Severe Lymphorrhea Following Resection of Soft-tissue Sarcomas of the Adductor Compartment: A Report of Two Cases

Case: Lymphedema and lymphorrhea are major causes of wound complications after the resection of soft-tissue sarcomas in the adductor compartment of the thigh. We report 2 cases of successful treatment of lymphedema and lymphorrhea, which had been refractory to nonoperative treatment, with use of lymphaticovenous anastomosis (LVA) and intraoperative indocyanine green lymphography after the resection of a sarcoma in the adductor compartment. Conclusion: These 2 cases highlight that LVA can be a useful and minimally invasive alternative to myocutaneous flaps for the treatment of wound complications caused by lymphedema and lymphorrhea after surgery for soft-tissue sarcomas in the adductor compartment of the thigh.

Anterior Impingement Syndrome of the Ankle Caused by Osteoid Osteoma in the Talar Neck Treated with Arthroscopy and 3D C-Arm-Based Imaging

Osteoid osteoma in periarticular lesions tends to have an unusual presentation that likely leads to a delayed or missed diagnosis compared with a typical osteoid osteoma in the metaphysis or diaphysis of the long bone. In cases that are unresponsive to conservative treatment, surgical interventions including en bloc resection, computed tomography-guided percutaneous treatment, and arthroscopic resection have been performed; however, these methods frequently result in inadequate tumor resection and recurrence. Here we present a case of a 16-year-old girl with osteoid osteoma in the talar neck presenting as anterior impingement syndrome due to marked synovitis in the ankle joint which was successfully treated without complications by arthroscopic synovectomy and tumor resection followed by intraoperative 3D C-arm-based imaging confirming complete tumor lesion removal. Her pain was relieved immediately after the surgery, and there was no recurrence at 12 months of follow-up. This is the first case report of the surgical treatment of the osteoid osteoma in the talar neck with the combination methods of arthroscopy and 3D C-arm-based imaging.