特殊組織型の食道悪性腫瘍―X線の立場から

Radiographic Findings of Esophageal Neoplasms Showing Rare Pathology

要旨　食道悪性腫瘍のほとんどは扁平上皮癌であり，その他の組織型は極めて少ない．われわれの施設における1,509例の経験では，扁平上皮癌1,382例（91.6％）と腺癌58例（3.8％）で95％以上を占め，その他の組織型（腺扁平上皮癌，類基底細胞癌，癌肉腫，未分化癌，悪性黒色腫）は69例（4.6％）と少なく特殊であり遭遇することは比較的まれと考えられる．しかし食道の未分化癌，悪性黒色腫は極めて悪性度が高いことはよく知られており，特殊組織型の中でも比較的頻度が高いことから，そのX線像の特徴を明らかにし，的確な治療方針の決定のため役立てていくことは重要である．

　We reviewed radiographic characteristics of esophageal malignant neoplasms with rare pathologic type, such as adenosquamous carcinoma (ASC), basaloid carcinoma (BC), carcinosarcoma (CS), undifferentiated carcinoma (UDC)and malignant melanoma (MM). Among these, the typical x-ray finding, pedunculated polypoid mass, of CSs is well known as previously reported. In our cases, superficial type lesions of BCs and MMs also showed distinctive pedunculated or sub-pedunculated protrusion in x-ray, and these types are not common in cases of squamous cell carcinoma. On the other hand, UDCs were generally identified as small submucosal-like lesions, which were difficult visualize by x-ray. It is essential to discriminate, by x-ray, UDC and MM from other types in patients with esophageal cancer, because patients with UDC and MM have quite poor prognosis, and it is important to determine their appropriate and effective treatments.