高見 諭加子¹, 谷 好子¹, 衛藤 美佐子¹, 栗本 美幸¹, 丸田 淳子¹, 橋本 裕信¹, 山下 裕人², 村上 司³, 野口 志郎⁴

Yukako TAKAMI¹, Yoshiko TANI¹, Misako ETO¹, Miyuki KURIMOTO¹, Junko MARUTA¹, Hironobu HASHIMOTO¹, Hiroto YAMASHITA², Tsukasa MURAKAMI³, Shiro NOGUCHI⁴

¹野口病院検査室, ²野口病院病理, ³野口病院内科, ⁴野口病院外科

¹Department of laboratory medicine, Noguchi Thyroid Clinic and Hospital Foundation, ²Department of pathology, Noguchi Thyroid Clinic and Hospital Foundation, ³Department of internal medicine, Noguchi Thyroid Clinic and Hospital Foundation, ⁴Department of surgery, Noguchi Thyroid Clinic and Hospital Foundation

キーワード : medullary thyroid carcinoma, ultrasonogram, thyroid nodule

目的：甲状腺髄様癌には超音波Bモード断層像上，乳頭癌を疑わせる不整形の結節として描出される例と濾胞腺腫を疑わせる卵円形の結節として描出される例があることが知られている．組織像との比較を行うことにより甲状腺髄様癌の超音波像の特徴とその成り立ちについて検討した．対象と方法：甲状腺髄様癌22例を超音波像の形状をもとに卵円形群と不整形群の2群に分け，切除標本のCongo-red染色，Elastica van Gieson染色を行い，腫瘍内のアミロイドおよび膠原線維の占める割合を比較検討した．また，超音波像で腫瘍内に高エコー部を認めた症例についてアミロイドとの関連を比較検討した．結果と考察：超音波像での形状の内訳は22症例中，卵円形群8（36.4％），不整形群14例（63.6％）であった．アミロイドと膠原線維の占める割合は卵円形群に比べ不整形群に有意（p＝0.0195，p＝0.0014）に高かった．超音波像で高エコー部が認められた症例は22例中15症例あり，そのうち13例が不整形であった．高エコー部を呈していた症例は切除標本にて全例石灰化を確認した．石灰化はアミロイド内や膠原線維内に存在しており，アミロイドの多い症例ほど高エコー部が多発していた．結論：アミロイド，膠原線維を含む間質の量が多い甲状腺髄様癌は不整形を示すことが多い．アミロイド沈着が高度な例に高エコー部が多い．

Purpose: In B-mode ultrasonographic examination (B-mode image), medullary thyroid carcinomas appear as irregularly shaped or ovate nodules suggestive of follicular adenomas and papillary carcinomas, respectively. In histologic studies, stromal components of medullary carcinoma such as amyloid deposition, fibrosis, and calcification vary from case to case. Ultrasonographic expression of these stromal factors remains unclear, however. The following studies were carried out to determine how these stromal factors are presented in B-mode images. Subjects and Methods: We used images from 22 cases of medullary carcinoma examined ultrasonographically and histologically. Ultrasonographic findings of these 22 medullary thyroid carcinomas were divided into two groups according to the shape of the nodules and into two more groups based on presence or absence of coarse, strong echoes. Histologic specimens of these 22 cases of medullary carcinoma were stained with Congo-red and Elastica van Gieson, and amyloid and fibrous tissues were evaluated semi-quantitatively. Results and Discussion: Eight of 22 cases ,were placed in the ovate group (36.4%); 14 in the irregularly-shaped group (63.6%). The amounts of amyloid and collagen tissues were significantly abundant in the irregularly-shaped group (p=0.0195 and p=0.0014, respectively). Coarse, strong echoes were found in 15 cases, 13 of which were in the irregularly shaped group. All cases with coarse, strong echoes showed histologic evidence of calcification Frequency of coarse, strong echoes tended to increase with amount of amyloid deposition. Conclusion: Medullary thyroid carcinomas shown as irregularly-shaped nodules contained abundant amounts of such histologically demonstrated stromal tissues as amyloid and collagen tissues. Medullary thyroid carcinomas containing large amounts of amyloid tissue produced many coarse, strong echoes.