Vascular problems of the pelvis

PHYSICAL SYMMETRY AND VIRTUAL PLANE-BASED REDUCTION REFERENCE: A PRELIMINARY STUDY FOR ROBOT-ASSISTED PELVIC FRACTURE REDUCTION

Traditional pelvis fracture reduction suffers from some disadvantages. Robot-assisted pelvis fracture reduction offers some promise in solving these problems. However, the reduction reference to guide robot motion is a key issue that must be resolved. In this paper, we propose a physical symmetry and virtual plane-based reduction reference and adopt the method of registration to calculate the virtual plane for the reference, which were verified via experiments. The results of the position symmetry experiments of the original pelvis and virtual plane-based position symmetry experiments were similar; both showed that the symmetry errors of the pelvis were less than 4[Formula: see text]mm and 2.5[Formula: see text]. The results indicated that the proposed method could be used as a reference for robot-assisted pelvis fracture reduction.

Fine-needle aspiration cytology of epithelioid angiosarcoma: A diagnostic dilemma

A 28-year-old woman with a 2-yr history of unilateral chronic leg swelling, initially thought to be secondary to deep vein thrombosis, later thought to be due to congenital venous malformation, eventually developed a pelvic mass, which was biopsied by fine-needle aspiration. On the basis of cytologic features on smears, high-grade sarcoma was reported. The patient underwent surgery to resect the pelvic mass, which showed anastomosing vascular channels arising from external iliac vein in histology. However, the tumor cells unexpectedly showed strong and diffuse immunohistochemical expression of cytokeratin and epithelial membrane antigen. The case was sent for expert consultation, and the expert's opinion was epithelioid angiosarcoma. The expert's diagnosis was confirmed 2 yr later by local recurrence. The clinical presentation, cytology, histology, and immunohistochemistry of the current case and 15 other cases of epithelioid angiosarcoma found in the cytology literature are summarized. This case illustrates that morphology with clinicopathologic correlation tends to be a better guide than available special techniques.