Undifferentiated pleomorphic sarcoma (UPS) is a high-grade pleomorphic neoplasm with no identifiable line(s) of differentiation using currently available diagnostic techniques. Therefore, it is essentially a diagnosis of exclusion, which requires generous tissue sampling, adequate contextually interpreted immunohistochemistry, and relevant molecular studies. UPS is a common soft tissue sarcoma (historically one of the entities referred to as malignant fibrous histiocytoma (MFH)), which can develop in various organs, but lung involvement is usually due to metastasis. Primary Pulmonary UPS (PPUPS) is exceptionally rare and here we present a 66-year-old man who presented with anemia and weight loss, found to have a 17 cm right lung mass with invasion to the chest wall and diaphragm. Extensive sampling and immunohistochemistry studies failed to reveal any line of differentiation. Upon exclusion of a possible extrapulmonary origin, a diagnosis of PPUPS was rendered. In addition, we reviewed all 84 previously reported cases of PPUPS/PPMFH in the literature since 1979 and summarized the clinical information.

Bone sarcomas are a collection of sporadic malignancies of mesenchymal origin. The most common subtypes include osteosarcoma, Ewing sarcoma, chondrosarcoma, and chordoma. Despite the use of aggressive treatment protocols consisting of extensive surgical resection, chemotherapy, and radiotherapy, outcomes have not significantly improved over the past few decades for osteosarcoma or Ewing sarcoma patients. In addition, chondrosarcoma and chordoma are resistant to both chemotherapy and radiation therapy. There is, therefore, an urgent need to elucidate which novel new therapies may affect bone sarcomas. Emerging checkpoint inhibitors have generated considerable attention for their clinical success in a variety of human cancers, which has led to works assessing their potential in bone sarcoma management. Here, we review the recent advances of anti-PD-1/PD-L1 and anti-CTLA-4 blockade as well as other promising new immune checkpoint targets for their use in bone sarcoma therapy.

We report the case of a clear cell chondrosarcoma (CCCS) occurring in the femoral head of a 14-year-old skeletally immature boy. Radiographic examination revealed a well-defined, osteolytic lesion in the epiphysis of the femoral head. Given the patient's age and the radiographic appearance of the lesion, chondroblastoma was high on the differential diagnosis. A frozen section was performed at the time of open biopsy was felt to be consistent with either chondroblastoma or CCCS. CCCS in a skeletally immature patient was felt to be unlikely, so curettage and bone grafting was performed. Final pathology review, however, confirmed the diagnosis of CCCS. The patient was taken back to surgery 4 weeks later for a wide resection and hemiarthroplasty.

Objective

The purpose of this article is to investigate potential technical, imaging, and histopathologic contributors to the success of CT biopsy.

Materials and methods

Four hundred forty-four consecutive CT biopsies of musculoskeletal lesions performed from 2005 to 2008 were retrospectively classified as diagnostic or nondiagnostic and as accurate or inaccurate. A biopsy was considered as diagnostic if it provided a definitive pathologic diagnosis or was clinically useful; as accurate if it was concordant with the ultimate diagnosis with respect to identification of malignancy, grade, and histopathologic features; and as successful if it was both diagnostic and accurate. Biopsy success rate, diagnostic yield, and accuracy were assessed according to lesion location, use of sedation, biopsy equipment type, bone lesion matrix type, and lesion histologic type (i.e., bone or soft-tissue origin, malignant or benign neoplasm, and low-or intermediate-to-high-grade neoplasm).

Results

Of 444 biopsies, 71% were diagnostic, 86% were accurate, and 70% were successful. Biopsy success and diagnostic yield were greater in bone lesions, malignant neoplasms, and intermediate-to-high-grade neoplasms compared with soft-tissue lesions (p < 0.01), benign neoplasms (p < 0.0001), and low-grade neoplasms (p < 0.0001). Success and diagnostic yield were not significantly associated with technical or imaging factors. Biopsy accuracy was not associated with any of the tested variables. Of the 128 nondiagnostic biopsy results, 53% were accurate with respect to subsequent surgical pathologic findings. Most of these biopsy results were of benign soft-tissue lesions.

Conclusion

CT biopsy of musculoskeletal lesions is accurate and effective. It may be limited in the evaluation of benign and low-grade soft-tissue neoplasms.

An intraneural hemangioma is a rare, benign mesodermal lesion. We present a case of a three-year-old female with the inability to straighten her right knee and fullness over the right popliteal fossa for one year. Magnetic resonance imaging (MRI) demonstrated a T2 hyperintense lesion of the popliteal fossa, within the tibial nerve. The patient underwent an uncomplicated right knee excisional biopsy, which confirmed the diagnosis of an intraneural hemangioma. Although rare, an intraneural hemangioma should be considered in the differential diagnosis of a soft tissue lesion located in the expected course of a peripheral nerve.

The use of image-guided percutaneous core needle biopsy (PCNB) to obtain tissue diagnosis of musculoskeletal lesions has become the standard of care in adult patients with a success rate of over 80%. Previous reports indicate a similar success rate in diagnosing pediatric solid tumors. In this large study, we analyzed >10 years of data in which PCNB was used for tissue diagnosis of musculoskeletal lesions in children; we evaluated the histopathologic accuracy, anesthetic requirements, and complications of these procedures. In 122 children, tissue diagnosis was successfully obtained in 82% of cases, and there were 0 complications associated with the procedure. There was a significantly higher PCNB diagnostic success rate in malignant lesions (93%). These data suggest that the use of PCNB is a safe and effective means of diagnosing musculoskeletal lesions in children.

Purpose

To retrospectively assess percutaneous core needle biopsies performed by radiologists and the association with tumor seeding along the biopsy tract when anatomic compartment guidelines are not consistently observed.

Materials and methods

Retrospective data from computerized patient records and digital images from 363 consecutive computed tomography-guided biopsies of the lower extremity (thigh and leg) performed by radiologists at a single institution from August 2002 to August 2008 were analyzed for breaches of biopsy guidelines.

Results

Of the 363 biopsies, 243 (67%) were of soft tissue lesions and 120 (33%) were of bony lesions. There were 188 (52%) malignant and 175 (48%) benign lesions. The following biopsy breaches were observed: 13 (3.6%) of anatomic compartment, 42 (11.6%) of "vital structures," and 82 (68.3%) of needle path for bony tumors. Vital structures as defined by the literature included, but were not limited to, the following: knee joint capsule, greater trochanteric bursa, rectus femoris and vastus intermedius muscles, tibial tubercle, peroneus brevis and peroneus longus distal tendons, and neurovascular bundles. No cases of tumor recurrences could be attributed to needle seeding along a biopsy tract for any of these biopsy guideline breaches.

Conclusions

The concern for needle tract seeding with musculoskeletal tumors is more widespread than the evidence supporting it as a significant or frequent complication. In this study, breaching anatomic compartment, vital structures (other than neurovascular structures), and suggested exact needle path guidelines were not associated with needle tract seeding in the lower extremity.

T-lymphokine-activated killer (T-LAK) cell-originated protein kinase (TOPK) is an emerging target with critical roles in various cancers; however, its expression and function in osteosarcoma remain unexplored. We evaluated TOPK expression using RNA sequencing and gene expression data from public databases (TARGET-OS, CCLE, GTEx, and GENT2) and immunohistochemistry in an osteosarcoma tissue microarray (TMA). TOPK gene expression was significantly higher in osteosarcoma than normal tissues and directly correlated with shorter overall survival. TOPK was overexpressed in 83.3% of the osteosarcoma specimens within our TMA and all osteosarcoma cell lines, whereas normal osteoblast cells had no aberrant expression. High expression of TOPK associated with metastasis, disease status, and shorter overall survival. Silencing of TOPK with small interfering RNA (siRNA) decreased cell viability, and inhibition with the selective inhibitor OTS514 suppressed osteosarcoma cell proliferation, migration, colony-forming ability, and spheroid growth. Enhanced chemotherapeutic sensitivity and a synergistic effect were also observed with the combination of OTS514 and either doxorubicin or cisplatin in osteosarcoma cell lines. Taken together, our study demonstrated that TOPK is a potential prognostic biomarker and therapeutic target for osteosarcoma treatment.