田中 亨

【背景】体腔液中に出現する反応性中皮細胞は,ときに悪性細胞との鑑別を要する.今回,卵巣癌の術中腹水細胞診で腺癌細胞との鑑別を要した反応性中皮細胞の1例を経験したので,その所見を報告する.【症例】患者は40歳代女性で,下腹部痛と腰痛を主訴に当センターを紹介受診した.CT・MRI検査にて腹膜転移を伴う卵巣癌が疑われた.入院後,子宮および両側付属器,腹膜結節,大網切除術を施行し,術中腹水細胞診検査を行った.その腹水細胞診標本では,炎症性背景に,多空胞状でライトグリーン淡好性の細胞質を有するやや大型の細胞集塊が少量認められた.明細胞癌を含めた腺癌細胞との鑑別を要したが,核の腫大や核クロマチンの濃染性,核形不整,核・細胞質比の増高はいずれも軽度で,細胞質は小空胞状を示し,細胞の重積性は目立たなかった.よって,細胞判定は陰性とし,中皮細胞の反応性変化と報告した.最終的な病理診断は右付属器原発の高異型度漿液性癌,骨盤外腹膜転移あり,大網転移なし,FIGO Stage IIIC期となった.【結論】腹水の細胞診断において中皮細胞の形態学的多様性を理解することは,腺癌を含めた悪性細胞との鑑別に有用と考えられる.(著者抄録)

We report a unique case of a 74-old man, who presented with double cancers, showing metastasis of pancreatic cancer to colon cancer. Histopathological examination after surgery revealed that the patient had ascending colon cancer, which metastasized to the liver (pT4N0M1), as well as pancreatic cancer (pT2N1M1) that metastasized to the most invasive portion of the colon cancer, namely the serosal to subserosal layers. Although the mechanisms for this scenario have yet to be elucidated, we speculate that the metastatic pancreatic carcinoma overtook the stromal microenvironment of the colon cancer. Namely, the cancer microenvironment enriched by cancer-associated fibroblasts, which supported the colon cancer, might be suitable for the invasion and engraftment by pancreatic carcinoma. The similarity of histological appearance might make it difficult to distinguish metastatic pancreatic carcinoma within colon cancer. Furthermore, the metastasis of pancreatic carcinoma in colon carcinoma might be more common, despite it not having been previously reported.

症例は57歳の女性.右下腹部腫瘤の精査で盲腸癌と診断された.術前の腹部超音波検査で肝S2に径10mmの境界明瞭で内部不均一な低エコー腫瘤を認めた.CT検査では淡い低吸収域として認め,造影効果は認めなかった.MRI検査ではT1強調で低信号,T2強調で軽度高信号を示し,superparamagnetic iron oxide(SPIO)造影後T2強調で明瞭な高信号として描出され,拡散強調画像で拡散の低下を認めた.盲腸癌・転移性肝癌と診断し,回盲部切除術と肝部分切除術を施行した.病理組織学的所見で肝reactive lymphoid hyperplasiaと診断された.術後8年再発なく経過している.肝reactive lymphoid hyperplasiaは良性疾患とされているが,術前検査で悪性腫瘍との鑑別が困難であり,外科的切除が行われることが多い.診断,治療の現状と問題点を考察した.(著者抄録)

INTRODUCTION: We report a patient with a rapidly progressing recurrence of hepatocellular carcinoma (HCC) with a portal vein tumor thrombus after radiofrequency ablation of the original lesion, then treated with transcatheter arterial infusion. Radical hepatic resection demonstrated a complete pathological response. PRESENTATION OF CASE: A 60-year old male with alcoholic cirrhosis and gastric varices was diagnosed with HCC measuring 12mm in segment 8. He underwent laparoscopic radiofrequency ablation, but recurred three months later. The lesion progressed rapidly and the right portal vein was occluded. He then underwent transcatheter arterial infusion with miriplatin and iodized oil, which was effective in reducing the size of the main lesion and portal vein tumor thrombus. Right anterior sectionectomy was then performed. Pathologically, there were no viable HCC cells in either the main lesion or the portal vein thrombus. He is alive two years and nine months after surgery without recurrence. DISCUSSION: A rapidly progressing HCC recurrence with portal vein tumor thrombus is usually associated with a poor prognosis. No effective treatments have been reported in this situation except hepatic resection. In this patient the tumor was effectively reduced after three courses of transarterial miriplatin and subsequent radical hepatic resection. This is the first report to achieve a complete pathological response for such an aggressive recurrence after initial radiofrequency ablation. CONCLUSION: This strategy may result in long-term survival of patients with rapidly progressing recurrent HCC with portal vein thrombus, and further study is warranted.

BACKGROUND: The endoscopic resection of early gastric cancers (EGC) is a standard technique in Japan and is increasingly used throughout the world. Further experience in the treatment of EGC and a clearer delineation of the factors related to lymph-node metastasis would permit a more accurate assessment of endoscopic resection. METHODS: The study group comprised 1,389 patients with EGC who underwent gastrectomy with lymph-node dissection. We evaluated the relations of lymph-node metastasis to clinicopathological factors. RESULTS: Of the 718 patients with intramucosal carcinomas, 14 (1.9%) had lymph-node metastasis. All cases of lymph-node metastasis were associated with ulceration. No lymph-node metastasis was found in patients with intramucosal carcinomas without ulceration, irrespective of tumor size and histological type. Lymph-node metastasis was present in 14 (4.7%) of the 296 patients who had cancer with a submucosal invasion depth of less than 500 microm (sm1). Significantly increased rates of lymph-node metastasis were associated with undifferentiated types, ulcerated lesions and lymphatic invasion. No lymph-node metastasis was found in patients with differentiated sm1 carcinomas 30 mm or less in diameter without ulceration. Lymph-node metastasis occurred in 29% of the patients who had cancer with a submucosal invasion depth of 500 microm or more (sm2). CONCLUSION: This large series of patients with EGC provides further evidence supporting the expansion of indications for endoscopic treatment, as well as warns against potential risks.