An easy approach to ultrasonographic volumetry of the thyroid.

To establish an easy way to perform volumetry of the thyroid gland using ultrasonography, we evaluated the accuracy of the products of the depth and width of the right thyroid lobe as indices of thyroid volume. The depth and width of both thyroid lobes were measured using ultrasonography before surgery in 193 patients with Graves' disease. The products were compared with the weight of the thyroid obtained from operative records. We also evaluated the depth and width of the right thyroid lobe in 312 subjects who presented without any thyroid disease. The products of depth and width of the right and left lobes of patients with Graves' disease correlated similarly well with the weight of the thyroid obtained from operative records (ρ = 0.896 for right, ρ = 0.886 for left, p < 0.0001). Because the right lobes were larger than the left lobes, the products of the depth and width of the right lobe were adopted as novel parameters for an easy volumetric approach. The relationship between the weight and the measurements of the right lobe was described using the following regression equation: weight (g) = [11.8 × depth (cm) × width (cm)] - 16.0. The products of the subjects without any thyroid diseases were distributed between 0.6 cm2 and 4.4 cm2, with a median of 2.0 cm2. The upper limit of these values in these subjects was estimated to be 3.8 cm2. This easy ultrasonographic volumetric technique makes it possible to perform a semi-quantitative assessment of thyroid volume and to differentiate diffuse goiter from normal-sized thyroids.

A case report of anaplastic thyroid carcinoma transformed from small papillary carcinoma successfully detected by ultrasonography in its early stage with review of literature.

An 82-year-old woman was referred to our hospital because of a suspicious thyroid nodule. She was diagnosed with papillary microcarcinoma with a maximum diameter of 9 mm based on ultrasonography and fine-needle aspiration (FNA) cytology. She preferred observation without surgery. Her papillary carcinoma grew gradually and reached a maximum diameter of 19 mm after 23 months. At that time, ultrasonography showed an apparent change in the shape of the nodule as well as in its diameter. At the initial ultrasound examination, papillary microcarcinoma was demonstrated as a hypoechoic solid nodule with an irregular shape. No punctuate microcalcifications were shown. After 23 months, the preexisting nodule had expanded toward the common carotid artery. The expanded portion was round and well demarcated. FNA revealed that the expanded portion consisted of anaplastic thyroid carcinoma. She underwent hemithyroidectomy and lymph node dissection of the central compartment. She remained in good health for 18 months after surgery. Anaplastic thyroid carcinoma is generally found as an aggressive large tumor, and the ultrasound appearance of small anaplastic thyroid carcinoma is poorly understood at present. We successfully detected anaplastic transformation in the early period by ultrasonography and FNA. When observation is indicated for small papillary thyroid carcinoma, the change in the shape of the nodule as well as in its diameter should be carefully monitored by ultrasonography. FNA should be performed at a proper site on the nodule to avoid overlooking anaplastic transformation, as resection following the early detection of anaplastic transformation might bring a favorable prognosis.

Thyroid storm induced by TSH-secreting pituitary adenoma: a case report.

Thyroid stimulating hormone-secreting pituitary adenomas (TSHomas) are uncommon tumors of the anterior pituitary gland. Patients with TSHomas may present with hyperthyroidism, but the incidence of thyroid storm due to TSHomas has yet to be determined. We report a rare case of thyroid storm caused by TSHoma in a 54-year-old woman. Preoperatively she had symptoms of excessive sweating and palpitation. Blood tests showed inappropriate secretion of TSH with blood TSH 6.86 µ U/mL, fT3 19.8 pg/mL, and fT4 5.95 ng/dL. Magnetic resonance imaging (MRI) revealed a pituitary tumor with maximum diameter of 13 mm that was extirpated through transsphenoidal route. After operation the patient was stuporous and thyroid storm occurred presenting with hyperthermia, hypertension, and tachycardia. It was well managed with nicardipine, midazolam, steroids, and potassium iodide. Immunohistochemical staining of tumor specimen was positive for TSH and growth hormone (GH). One year after operation, fT3 and fT4 levels were still high. As her tumor was diagnosed to be GH- and TSH-producing adenoma, octreotide injection therapy was started, which normalized thyroid hormone levels. This is the second reported case with thyroid storm due to TSHoma and emphasizes the importance of strategies with interdisciplinary cooperation for prevention of such emergency conditions.