Thyroid fine-needle aspiration biopsy in children and adolescents: experience with 218 aspirates.

To evaluate the role of fine-needle aspiration (FNA) biopsy of thyroid nodules in pediatric and adolescent patients, the cytology reports of 218 thyroid FNA biopsies performed on children and adolescents ranging from 10 to 21 yr of age were reviewed. The cytology diagnoses were categorized into four groups: unsatisfactory, benign, suspicious, and malignant. One hundred nineteen (54%) of the aspirates were diagnosed as "benign," 20 (9%) were diagnosed as suspicious for malignancy; and 17 (8%) were diagnosed as malignant. Sixty-two (28%) of the aspirates were read as unsatisfactory for interpretation. Sensitivity of thyroid FNA in diagnosing thyroid malignancy relative to final histological diagnoses was 100%, and specificity was 65%. FNA of thyroid nodules in the pediatric and adolescent population is comparably as sensitive and specific as in the adult population. The acceptance of this procedure in the routine evaluation of young patients' thyroid nodules should reduce the number of unnecessary surgeries for benign thyroid disease.

Adenocarcinomas of the gastrointestinal tract with prominent rhabdoid features.

Rhabdoid tumor, first described in kidneys of infants and children, is an aggressive tumor that has been reported in several extrarenal locations. Gastrointestinal tumors with rhabdoid features are extremely rare. The effect of the rhabdoid phenotype on the aggressiveness of gastrointestinal tumors remains unclear. We present four cases of rhabdoid tumors of the gastrointestinal tract involving the esophagus, stomach, and small intestine and discuss the clinicopathologic, immunohistochemical, and ultrastructural features. In the four cases reported herein, the patients' ages ranged from 52 to 73 years, and tumor size ranged from 3.8 to 13 cm in greatest dimension. The noncohesive rhabdoid cells exhibited an eccentric nucleus with a paranuclear inclusion, which was shown by electron microscopic examination to be composed of intermediate filaments. On immunohistochemical staining, the tumor cells were positive for vimentin and cytokeratin. Three patients developed distant metastasis shortly after diagnosis and died of disease within 2 to 10 months after initial presentation. A retrospective review of outcomes of the current cases and previously published literature showed that 12 (75%) of the 16 patients died within 6 months of presentation. Recognition of the rhabdoid phenotype in gastrointestinal tract neoplasms is important because this feature is associated with poor prognosis and unresponsiveness to conventional therapy.

Repressors of androgen and progesterone receptor action.

Androgen and progesterone receptors (AR and PR) are two determining factors in gonadal differentiation that are highly expressed in developing and mature gonads. Loss of AR results in XY sex reversal and mutations causing reduced AR activity lead to varying degrees of defects in masculinization. Female PR knockout mice are infertile due to ovarian defects. While much has been discovered about positive regulation of these receptors by coactivators little is known about repression of the transcriptional activity of AR and PR in the presence of agonists. In this study we assessed the effect of SMRT and DAX-1 on AR and PR activity in the presence of both agonists and partial antagonists. We show that SMRT and DAX-1 repress agonist-dependent activity of both receptors, and the mechanism of repression includes disruption of the receptor dimer interactions rather than recruitment of histone deacetylases. We demonstrate that endogenous agonist-bound PR and DAX-1 in T47D breast cancer cells and endogenous AR and DAX-1 in LNCaP prostate cancer cells can be coimmunoprecipitated suggesting that the interaction is physiological. Surprisingly, although DAX-1 represses partial antagonist activity of AR, it was ineffective in repressing partial antagonist induced activity of PR. In contrast to most reported repressors, the expression of DAX-1 is restricted. We found that although DAX-1 is expressed in normal human prostate, its expression is strongly reduced in benign prostatic hyperplasia suggesting that DAX-1 plays a role in limiting AR activity in prostate.