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Biomedical subjects

K Shimaoka

Publications and source records attributed to K Shimaoka.

87 records · Page 5Linked to original sources
PubMed1976

Thyrotoxicosis secondary to involvement of the thyroid with malignant lymphoma.

A patient with malignant lymphoma developed goiter and thyrotoxicosis during the course of her disease. A thyroid biopsy revealed involvement of the thyroid gland with a malignant lymphoma. This was associated with the high levels of circulating thyroglobulin and thyroid hormones. The patient was treated with propylthiouracil, local radiotherapy, and nitrogen mustard and prednisone. The patient became euthyroid with the disappearance of goiter. Circulating levels of thyroglobulin and thyroid hormones returned to the normal range.

Adult↗
PubMed1975

Differentiation of two abnormalities in thyroid peroxidase causing organification defect and goitrous hypothyroidism.

Clinical and laboratory evaluations are reported on two patients with congenital goiter and hypothyroidism due to iodide organification defect. In one patient, a 31-year-old white male with severe mental retardation, administration of perchlorate caused discharge of 69% of the radioiodine accumulated in the thyroid gland. Thyroid tissue had negligible peroxidase activity in the tyrosine-iodinase, triliodide, and guaiacol assays. Preincubation of subcellular fractions with hematin restored activity. The restored enzyme was labile to high concentrations of H2O2 (5.6times 10-4 h2o2 produced inhibition in the triiodide assay). Heating of the enzyme for 5 min at 46 degrees C produced 50% inactivation, while higher temperatures were required to half-inactivate normal peroxidases. This case represents a second example of the "peroxidase apoenzyme-prosthetic group defect" causing congenital goiter. The second patient, an example of the "deficient peroxidase defect," was a 10-yr-old girl with 35% discharge of thyroidal radioiodine by perchlorate. Peroxidase activity in the goiter tissue was quantitatively decreased (10%-20% of normal values) but kinetically normal with respect to apparent Km for H2O2. Hematin had little effect on the enzyme. Peroxidase activity had abnormal subcellular distribution, since pellets sedimenting between 39,000 and 105,000 g contained most of the activity. Normal thyroglobulin was observed in the thyroid gland of the patient. Two distinct defects of the peroxidase system can produce congenital goiter by limiting organification of iodide.

Adult↗
PubMedDate not supplied

Rarity of squamous cell carcinoma of the thyroid: autopsy review.

Squamous cell carcinoma (SCC) of the thyroid is thought to be rare. However, SCC not infrequently occurs in conjunction with other histologic types of tumor. We reviewed 67 thyroid cancer autopsy cases obtained from two institutions from 1969 to 1981 and from 1975 to 1992, respectively. SCC was found in 19 cases (28.4%): 2 SCCs as the only malignancy and of uniform histologic type, 9 cases of tumors mixed with papillary carcinoma, and 8 cases of SCC mixed with papillary and anaplastic carcinomas. In only four of these cases was the SCC component found in the surgical specimens. These results indicate that the presence of SCC component is more likely to be found at the later stage of the disease.

Adult↗
PubMedDate not supplied

Needle aspiration of 310 thyroid lesions.

Needle aspirations of benign and malignant epithelial lesions of the thyroid were investigated in 265 patients. An 18-gauge needle connected to a 20-cc glass syringe was used to puncture each tumoral mass. Smears were stained by the Wright-Giemsa method. The material obtained consisted of 180 nontoxic goiters, 18 toxic goiters, 15 cases of thyroiditis and 52 malignant lesions. Aspirations taken from 21 patients (8%) were either blank or contained only blood and insufficient material for diagnosis. Results were correlated with clinical findings and laboratory tests. Biopsies were obtained only in selected patients to establish the final diagnosis. One false positive and one false negative were recorded. Although well-preserved follicular patterns can be seen on the cytologic specimens, the differentiation of thyroid adenoma from early follicular carcinoma based on cytologic criteria only if fraught with many difficulties. Cell density, nuclear structure and presence of nucleoli are sometimes helpful in making the cytologic diagnosis of thyroid carcinoma.

Biopsy, Needle↗
PubMedDate not supplied

Parathyroid adenoma diagnosed as papillary carcinoma of thyroid on needle aspiration smears.

Needle aspiration of a neck mass was performed on a 55-year-old white female with hypercalcemia. The cytologic material showed cohesive clusters of monomorphic hyperchromatic cells resembling follicular cells. Papillary formation and follicle-like arrangements suggested papillary carcinoma of the thyroid. The histopathologic section of the excised mass, however, revealed a parathyroid adenoma. The diagnostic difficulties in differentiating parathyroid adenoma from well-differentiated thyroid carcinoma are discussed. Data published in the literature emphasize similar difficulties, and it is concluded that a final diagnosis can be established only on histopathologic sections.

Adenoma↗
PubMedDate not supplied

Diagnosis of chronic lymphocytic thyroiditis (nodular presentation) by needle aspiration.

Needle aspiration was performed on 40 patients with a diagnosis of chronic lymphocytic thyroiditis, and the cytologic findings are described. Clinically, 32 patients had a nodular lesion or lesions, and 8 had diffuse enlargement of the thyroid. A 20-ml glass syringe and an 18-gauge needle were used to aspirate the lesions, and smears were stained according to the Wright-Giemsa technique. Diagnostic material was obtained in 36 patients, and in 4 the aspirate was unsatisfactory. There was good correlation between cytologic findings and antibody tests. Thirteen patients underwent surgical excision of the lesions, and the diagnosis was confirmed histologically. In one patient, the histopathologic diagnosis was chronic lymphocytic thyroiditis and thyroid adenoma. The latter component was not recognized initially on the cytologic specimen. The abundant cellular material obtained in the early nodular forms may correspond to a cellular phase of the disease as opposed to a later fibrotic phase. The evaluation of the epithelial-lymphoid ratio is stressed, and substantial alteration of this ratio may suggest an association of chronic lymphocytic thyroiditis with other thyroid lesions, benign or malignant.

Adolescent↗