A Case of medullary thyroid carcinoma with de novo V804M RET germline mutation.

Many cases of RET proto-oncogene mutations of hereditary medullary thyroid carcinoma (MTC) have been reported in Korea. However, MTC with V804M RET proto-oncogene germline mutations have not been reported in Korea. A 33-yr-old man was diagnosed with a 0.7-cm sized thyroid nodule. Laboratory testing revealed serum calcitonin was elevated. The patient underwent total thyroidectomy with central compartment neck dissection for the thyroid tumor. RET gene analysis was performed in both the index patient and his family. There were no V804M RET mutation and abnormal laboratory findings within his family except the index patient. Therefore, this patient was a de novo V804M RET germline mutation.

Co-occurrence of papillary thyroid carcinoma and mucosa-associated lymphoid tissue lymphoma in a patient with long-standing hashimoto thyroiditis.

Papillary thyroid carcinoma (PTC) is a common affliction of the thyroid gland, accounting for 70% to 80% of all thyroid cancers, whereas mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland is uncommon. The simultaneous occurrence of both malignancies is extremely rare. We report the case of a patient with both PTC and MALT lymphoma in the setting of Hashimoto thyroiditis. An 81-year-old female patient was first admitted with goiter and hoarseness, which was attributed to an ultrasonographic thyroid nodule. Subsequent fine-needle aspirate, interpreted as suspicious of papillary thyroid cancer, prompted total thyroidectomy. MALT lymphoma was an incidental postsurgical finding, coexisting with PTC in the setting of Hashimoto thyroiditis. Although the development of MALT lymphoma is very rare, patients with longstanding Hashimoto thyroiditis should undergo careful surveillance for both malignancies.

Disruption of insulin-like growth factor-I expression in type IIalphaI collagen-expressing cells reduces bone length and width in mice.

It is well established that insulin-like growth factor (IGF)-I is critical for the regulation of peak bone mineral density (BMD) and bone width. However, the role of systemic vs. local IGF-I is not well understood. To determine the role local IGF-I plays in regulating BMD and bone width, we crossed IGF-I flox/flox mice with procollagen, typeIIalphaI-Cre mice to generate conditional mutants in which chondrocyte-derived IGF-I was disrupted. Bone parameters were measured by dual X-ray absorptiometry at 2, 4, 8, and 12 wk of age and peripheral quantitative computed tomography at 12 wk of age. Body length, areal BMD, and bone mineral content (BMC) were reduced (P < 0.05) between 4 and 12 wk in the conditional mutant mice. Bone width was reduced 7% in the vertebrae and femur (P < 0.05) of conditional mutant mice at 12 wk. Gains in body length and total body BMC and BMD were reduced by 27, 22, and 18%, respectively (P < 0.05) in conditional mutant mice between 2 and 4 wk of age. Expression of parathyroid hormone related protein, parathyroid hormone receptor, distal-less homeobox (Dlx)-5, SRY-box containing gene-9, and IGF binding protein (IGFBP)-5 were reduced 27, 36, 45, 33, and 45%, respectively, in the conditional mutant cartilage (P < 0.05); however, no changes in Indian hedgehog, Dlx-3, growth hormone receptor, IGF-I receptor, and IGFBP-3 expression were observed (P > or = 0.20). In conclusion, IGF-I from cells expressing procollagen type IIalphaI regulates bone accretion that occurs during postnatal growth period.

Whole genome microarray analysis of growth hormone-induced gene expression in bone: T-box3, a novel transcription factor, regulates osteoblast proliferation.

Growth hormone (GH) is important in the development and maintenance of bone; however, the IGF-dependent and -independent molecular pathways involved remain to be established. We used microarray analysis to evaluate GH signaling pathways in 4-wk-old GH-deficient mice following a single injection of GH (4 mg/kg body wt) or PBS (n = 6/group) at 6 or 24 h after treatment. Six thousand one hundred sixty genes were differentially expressed at P