PURPOSE: The goal of this study was to determine the risk of malignancy of thyroid nodules with minimal cystic changes. METHODS: A total of consecutive 1,000 thyroid nodules (≥1 cm) with final diagnoses from twoinstitutions were included in this study. The risk of malignancy of thyroid nodules was analyzed according to the internal content, which was categorized as purely solid, minimally cystic (cystic changes ≤10%), and partially cystic (cystic changes >10%). We also assessed the risk of malignancy of nodules with minimal cystic changes depending on echogenicity and presence of any suspicious ultrasonografic (US) features. RESULTS: The overall frequency of purely solid, minimally cystic, and partially cystic noduleswas 730/1,000 (73%), 61/1,000 (6.1%), and 209/1,000 (20.9%), respectively, with risks ofmalignancy of 14.8% (108/730), 3.3% (2/61), and 3.3% (7/209), respectively. The risk ofmalignancy of nodules with minimal cystic changes was significantly lower than that of purelysolid nodules (P=0.013). The risk of malignancy of nodules with minimal cystic changes was also lower than that of purely solid nodules in the group of hypoechoic nodules (P=0.063) and in the group of nodules with suspicious US features (P=0.028), but was not significantly different from that of partially cystic nodules regardless of echogenicity or the presence of suspicious US features (P≥0.652). CONCLUSION: Thyroid nodules with minimal cystic changes have a low risk of malignancy, similar to that of partially cystic nodules regardless of echogenicity or the presence of suspicious US features. The US lexicon could define solid nodules as nodules with purely solid internal content in order to enhance the accuracy of estimated risks of malignancy.
Diagnosis ; Thyroid Gland* ; Thyroid Nodule* ; Ultrasonography

STUDY DESIGN: Retrospective, controlled study OBJECTIVE: To compare one and two-caged posterior lumbar interbody fusion (PLIF) with local bone grafting for spondylolisthesis. SUMMARY OF LITERATURE REVIEW: Even though there are many reports on PLIF using cages and local bone grafting, Studies comparing one and two-caged PLIFs are rare. MATERIALS AND METHODS: Sixty-three patients who underwent pedicle screw fixated PLIF using cages and local bone grafts were followed for more than 1 year. Twenty-five patients had one cage (group I), and 38 patients had two cages (group II). Sampling error, disc height, sagittal Cobb angle, coronal Cobb angle, fusion rate, Oswestry disability index (ODI), operation time, blood loss, and neurologic complications were assessed. RESULTS: There was no sampling error between the two groups, except with regard to diagnosis: degenerative spondylolisthesis, 15 cases in group I and 9 cases in group II; spondylolytic spondylolisthesis, 10 cases in group I and 29 cases in group II (p=0.004). Fusion rates were 87.5% and 88.2% for groups I and II, respectively (p=1.000). More disc height loss occurred in group I (0.6 mm) than in group II (0.0 mm) (p=0.041). Over-3mm-disc height-losses were noted more frequently in group I (20%) than in group II (2.6%) (p=0.022). ODI improved from 28.1 to 12.3 (72.1% improvement) in group I and from 29.2 to 12.7 (79.3% improvement) in group II. There were no significant differences in operation time, amount of blood loss, or neurologic complications between the two groups. CONCLUSION: Unilateral one-caged PLIF with local bone grafting and posterior instrumentation was no different from bilateral two-caged PLIF with regard to fusion rates or radiologic or clinical results. The statistically significant differences in disc height seemed to be clinically insignificant. Disc height loss of greater than 3 mm was much more common in group I, with one-caged PLIF.
Bone Transplantation ; Humans ; Retrospective Studies ; Selection Bias ; Spondylolisthesis ; Transplants

Syringocystadenocarcinoma papilliferum in situ is extremely rare. A 51-year-old female presented with a solitary yellowish patch on the scalp, accompanied by hair loss and a protruding mass. Histopathological evaluation revealed a large number of sebaceous glands and mild papillomatosis without hair follicles. The tumor contained many cystic spaces filled with amorphous material and a connection to the epidermis. The tumor cells showed papillomatous projections and were multilayered with nuclear atypia but no dermal involvement or lymphovascular invasion. On immunohistochemical analysis, the tumor cells showed immunopositivity for carcinoembryonic antigen, Ki-67, epithelial membrane antigen, and gross cystic disease fluid protein-15. Therefore, the patient was diagnosed with syringocystadenocarcinoma papilliferum in situ originating from a nevus sebaceus. The tumor was removed by wide excision, and no recurrence was observed. Our case report supports the multistep pathogenesis of syringocystadenocarcinoma papilliferum originating from a nevus sebaceus.

Syringocystadenocarcinoma papilliferum in situ is extremely rare. A 51-year-old female presented with a solitary yellowish patch on the scalp, accompanied by hair loss and a protruding mass. Histopathological evaluation revealed a large number of sebaceous glands and mild papillomatosis without hair follicles. The tumor contained many cystic spaces filled with amorphous material and a connection to the epidermis. The tumor cells showed papillomatous projections and were multilayered with nuclear atypia but no dermal involvement or lymphovascular invasion. On immunohistochemical analysis, the tumor cells showed immunopositivity for carcinoembryonic antigen, Ki-67, epithelial membrane antigen, and gross cystic disease fluid protein-15. Therefore, the patient was diagnosed with syringocystadenocarcinoma papilliferum in situ originating from a nevus sebaceus. The tumor was removed by wide excision, and no recurrence was observed. Our case report supports the multistep pathogenesis of syringocystadenocarcinoma papilliferum originating from a nevus sebaceus.

Liver tissuses obtained from 5 human fetuses between 11 weeks and 23 weeks of gestation during the high activity of hepatic hemopoiesis were observed with transmission electron microscope using continuous series of thin sections. The objective of present study was to evaluate ultrastructures of megakaryopoietic cells, the migration of extravascular megakaryocyte into the sinusoidal lumen and the relevence between a migrated megakaryocyte and a Kupffer cell. Immature megakaryocytes were usually observed between growing hepatic laminae and within hepatic sinusoids. A megakaryoblast contained numerous polyribosomes, rather large mitochondria, short tubular elements of rough endoplasmic reticulum and small granules. Moreover, demarcation tubules and a few small specific granules were observed in immature megakaryocytes. The nucleus was mononuclear but frequently indented. With maturation, the nuclei were multilobulated. In the cytoplasm, in contrast to the decrease in polyribosomes and rough endoplasmic reticulum, the numerous specific granules and well -developed demarcation membrane system were predominant. Thereafter cytoplasmic zonation was observed clearly in maturing and mature megakaryocytes. Some megakaryocytes passed through the sinusoidal lining epithelium and into the hepatic sinusoids. The cell to cell interaction was often found as adhesion between migrated megakaryocyte and Kupffer cell, and erythroblasts within megakaryocyte (emperipolesis). These results suggest that intravascular megakaryopoiesis in addition to extravascular megakaryopoiesis occurs to produce platelet during the human fetal liver.
Blood Platelets ; Cell Communication ; Cytoplasm ; Emperipolesis ; Endoplasmic Reticulum, Rough ; Epithelium ; Erythroblasts ; Fetus* ; Humans* ; Liver ; Megakaryocyte Progenitor Cells ; Megakaryocytes* ; Membranes ; Mitochondria ; Polyribosomes ; Pregnancy ; Thrombopoiesis

STUDY DESIGN: Mechanical study of polymethylmetacrylate (PMMA) mixed with blood as a filler. PURPOSE: An attempt was made to modify the properties of PMMA to make it more suitable for percutaneous vertebroplasty (PVP). OVERVIEW OF LITERATURE: The expected mechanical changes by adding a filler into PMMA included decreasing the Young's modulus, polymerization temperature and setting time. These changes in PMMA were considered to be more suitable and adaptable conditions in PVP for an osteoporotic vertebral compression fracture. METHODS: Porous PMMA were produced by mixing 2 ml (B2), 4 ml (B4) and 6 ml (B6) of blood as a filler with 20 g of regular PMMA. The mechanical properties were examined and compared with regular PMMA(R) in view of the Young's modulus, polymerization temperature, setting time and optimal passing-time within an injectable viscosity (20-50 N-needed) through a 2.8 mm-diameter cement-filler tube. The porosity was examined using microcomputed tomography. RESULTS: The Young's modulus decreased from 919.5 MPa (R) to 701.0 MPa (B2), 693.5 Mpa (B4), and 545.6 MPa (B6). The polymerization temperature decreased from 74.2degrees C (R) to 59.8degrees C (B2), 54.2degrees C (B4) and 47.5degrees C (B6). The setting time decreased from 1,065 seconds (R) to 624 seconds (B2), 678 seconds (B4), and 606 seconds (B6), and the optimal passing-time decreased from 75.6 seconds (R) to 46.6 seconds (B2), 65.0 seconds (B4), and 79.0 seconds (B6). The porosity increased from 4.2% (R) to 27.6% (B2), 27.5% (B4) and 29.5% (B6). A homogenous microstructure with very fine pores was observed in all blood-mixed PMMAs. CONCLUSIONS: Blood is an excellent filler for PMMA. Group B6 showed more suitable mechanical properties, including a lower elastic modulus due to the higher porosity, less heating and retarded optimal passing-time by the serum barrier, which reduced the level of friction between PMMA and a cement-filler tube.
Elastic Modulus ; Fractures, Compression ; Friction ; Heating ; Hot Temperature ; Polymerization ; Polymers ; Polymethyl Methacrylate ; Porosity ; Vertebroplasty ; Viscosity ; X-Ray Microtomography

STUDY DESIGN: This is a mechanical study of polymethylmetacrylate(PMMA) mixed with blood as a filler. OBJECTIVE: We tried to change the properties of PMMA so that it is more suitable to use for percutaneous vertebroplasty (PVP). SUMMARY OF THE LITERATURE REVIEW: The mechanical changes by adding a filler into PMMA were expected to decrease the Young's modulus, the polymerization temperature and the setting time. These changes of PMMA were considered to be more suitable and adaptable conditions for PVP for treating osteoporotic vertebral compression fracture. MATERIALS AND METHODS: Porous PMMA was produced by mixing 2 ml (B2), 4 ml (B4) and 6 ml (B6)-blood as a filler, and the mechanical properties were investigated in comparison with regular PMMA(R) in view of Young's modulus, the polymerization temperature, the setting time and the optimal passing-time within the injectable viscosity (20~50N-needed) through a 2.8mm-diameter cement-filler tube. Porosity was inspected by performing microcomputated tomography (micro-CT). RESULTS: Young's modulus was decreased from 919.5 MPa (R) to 701 MPa (B2), 693.5 MPa (B4) and 545.6 MPa (B6) in each group. The polymerization temperature decreased from 74.2degrees C (R) to 59.8degrees C (B2), 54.2degrees C (B4) and 47.5degrees C(B6), respectively. The setting time decreased from 1065sec (R) to 624sec (B2), 678sec(B4) and 606sec (B6), respectively, and the optimal passing-time decreased from 75.6sec (R) to 46.6sec (B2), 65.0sec (B4) and 79.0sec(B6), respectively. The porosity increased from 4.2%(R) to 27.6%(B2), 27.5%(B4) and 29.5%(B6), respectively. A homogenous microstructure with very fine pores was seen on inspection of all the blood-mixed PMMAs. CONCLUSION: Blood mixed with PMMA was considered as an excellent filler that was easy to make and had good biocompatibility. The 6ml blood-mixed PMMA (B6) showed more suitable mechanical properties, including a decreased elastic modulus due to more porosity, less heating and a retarded optimal passing-time by the serum barrier, which diminished the friction between the PMMA and a cement-filler tube.
Elastic Modulus ; Fractures, Compression ; Friction ; Heating ; Hot Temperature ; Polymerization ; Polymers ; Polymethyl Methacrylate ; Porosity ; Vertebroplasty ; Viscosity