The Smallest Reported Malignant Struma Ovarii: A Case Report

Introduction: Malignant struma ovarii is a rare neoplasm. It is usually asymptomatic and not commonly diagnosed preoperatively. In addition, there is currently no established diagnostic and therapeutic approach for malignant struma ovarii. Case Report: A 66-year-old asymptomatic female was referred to our hospital. Computed tomography showed the presence of a well-defined mass with enhancement in the internal and peripheral areas. The patient underwent total abdominal hysterectomy, bilateral salpingo-oophorectomy, and partial omentectomy. Histopathology revealed the presence of a papillary thyroid carcinoma arising from a 2.5-cm-diameter struma ovarii (malignant struma ovarii). According to the criteria of the International Federation of Gynecology and Obstetrics, the patient had stage IA disease. Subsequently, she underwent a thyroid scan with normal findings. At the 3-month follow-up, the patient was alive, in good clinical condition, and disease free. Conclusion: In this report, we present the smallest malignant struma ovarii reported so far in the literature. Because of the rarity of these tumors and the lack of firm prognostic factors, the treatment decision should be customized for each patient according to the pathological and clinical parameters

Immune-related gene expression profile in laboratory common marmosets assessed by an accurate quantitative real-time PCR using selected reference genes.

The common marmoset (Callithrix jacchus) is considered a novel experimental animal model of non-human primates. However, due to antibody unavailability, immunological and pathological studies have not been adequately conducted in various disease models of common marmoset. Quantitative real-time PCR (qPCR) is a powerful tool to examine gene expression levels. Recent reports have shown that selection of internal reference housekeeping genes are required for accurate normalization of gene expression. To develop a reliable qPCR method in common marmoset, we used geNorm applets to evaluate the expression stability of eight candidate reference genes (GAPDH, ACTB, rRNA, B2M, UBC, HPRT, SDHA and TBP) in various tissues from laboratory common marmosets. geNorm analysis showed that GAPDH, ACTB, SDHA and TBP were generally ranked high in stability followed by UBC. In contrast, HPRT, rRNA and B2M exhibited lower expression stability than other genes in most tissues analyzed. Furthermore, by using the improved qPCR with selected reference genes, we analyzed the expression levels of CD antigens (CD3ε, CD4, CD8α and CD20) and cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12β, IL-13, IFN-γ and TNF-α) in peripheral blood leukocytes and compared them between common marmosets and humans. The expression levels of CD4 and IL-4 were lower in common marmosets than in humans whereas those of IL-10, IL-12β and IFN-γ were higher in the common marmoset. The ratio of Th1-related gene expression level to that of Th2-related genes was inverted in common marmosets. We confirmed the inverted ratio of CD4 to CD8 in common marmosets by flow cytometric analysis. Therefore, the difference in Th1/Th2 balance between common marmosets and humans may affect host defense and/or disease susceptibility, which should be carefully considered when using common marmoset as an experimental model for biomedical research

CD8/CD4 ratio in PBMCs from young and old marmosets.

*<p>Only FACS analysis, but not qPCR, was done with PBMCs from these three marmosets.</p

The expression ratios of CD8 to CD4 (CD8∶CD4) and Th1-related genes to Th2-related genes.

<p>The ratio of CD8∶CD4 (left panel), IFN-γ∶IL-4 (middle panel) and IL-2∶IL-4 (right panel) in human and common marmoset leukocytes, spleen, lymph node and thymus are shown. Significant differences in the CD8∶CD4, IFN-γ∶IL-4 and IL-2∶IL-4 ratios were found between human leukocytes and common marmoset tissues (*<i>P</i><0.05).</p

The expression levels of CD antigens and cytokine genes in common marmoset and human leukocytes.

<p>The expression level of each gene is shown as a logarithmic histogram of absolute copy numbers per µg of total RNA. Means and standard deviations of eight individuals are indicated. Asterisk indicates statistically significant differences between marmosets and humans by Student's <i>t</i>-test (*<i>P</i> value<0.05, **<i>P</i> value<0.01).</p

Sequences of qPCR primers for CD markers and cytokines.

a)<p>Hyphen indicates a nucleotide identical to human sequences.</p>b)<p>Dot indicates a shift nucleotide to marmoset sequences.</p

Gene expression stability and pairwise variation of candidate reference genes using <i>geNorm</i> analysis.

<p>(A) and (B): Average gene expression stability values M of the remaining reference genes during stepwise exclusion of the least stable gene in the different tissue panels are shown. Data are divided into two figures to avoid closely-packed lines. See also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056296#pone-0056296-g003" target="_blank">figure 3</a> for the ranking of genes according to their expression stability. (C) Pairwise variation analysis was used to determine the optimal number of reference genes for use in qPCR data normalization. The recommended limit for V value is 0.15, the point at which it is unnecessary to include additional genes in a normalization strategy.</p