多発性筋炎に合併した間質性肺炎，偽性腸管閉塞症および腸管囊腫様気腫の1例

Interstitial Pneumonia, Intestinal Pseudo-obstruction and Pneumatosis Cystoides Intestinalis Associated with Polymyositis, Report of a Case

　偽性腸管閉塞症intestinal pseudo-obstruction（以下IPOと略す）とは，腸閉塞類似の症状を呈し，X線検査で認められた腸管腔の閉塞や狭窄が，手術や剖検で確認できない病態を言い，また，腸管囊腫様気腫pneumatosis cystoides intestinalis（以下PCIと略す）は，腸管の粘膜下や漿膜下に，気体がびまん性に散在して認められる病態を言い，双方とも原因は不明である．PCIでは腹腔内遊離ガスを高率に認めるため，IPO同様，不適切な手術の行われる危険がある．現時点では，PCIの気体の由来として，消化管と肺胞が考えられており，今回われわれの経験したPCIは，間質性肺炎とIPOを呈した多発性筋炎の症例であり，PCIの発生機序を考えるうえで興味深く，膠原病とPCIの関連とも併せて報告する．

　以下，膠原病の病名は下記の略語を使用する．PSS（進行性全身性硬化症），SLE（全身性エリテマトーデス），PM（多発性筋炎：皮膚筋炎を含む），RA（慢性関節リウマチ），PN（結節性動脈周囲炎），MCTD（混合性結合組織病）．

　A 46-year-old office woman of interstitial pneumonia (IP) successfully treated with corticosteroid for one year, was readmitted to Seirei Hamamatsu Hospital on January 21, 1980 because of weakness with alternating diarrhea and constipation since two months. The histopathological findings of muscle biopsy were compatible with polymyositis (PM). The increasing dosage of corticosteroid inproved weakness, but nausea and vomiting occured once in several weeks, when abdominal radiographs showed air-fluid levels. The patient vomited seriously on May 14, and the x-ray film taken on the following day revealed pneumatosis cystoides intestinalis (PCI); air accumulations were found in the wall of the intestine (probably both of colon and small intestine), mesentery and retroperitoneum. The chest x-ray film demonstrated free intraperitoneal air, but no aggravation of IP. PCI disappeared spontaneously after one week. The gastrointestinal examination showed barium stagnation in the esophagus, dilated duodenal loop and stenosis at the end of duodenum, but in colon there were no marked findings except hypoperistalsis. The several stenosis of small intestine suggesting neoplasm were found, but these stenosis disappeared rapidly by intravenous injection of neostigmine. These findings were compatible with intestinal pseudo-obstruction (IPO) which is common in progressive systemic sclerosis (PSS), however, in our case no evidence of PSS was revealed in skin biopsy performed on June 5. The oral administration of pridostigmine was remarkably effective for the symptomatic improvement and the prevention of PCI.

　In our literature review, there were only two cases of PCI with PM in 23 cases of collagen diseases combined with PCI. The PCI occurred in our case was thought to be caused not by IP but by IPO, because IP was improved and stable at that time. On the other hand, however, the alveolar rupture caused by severe vomiting was considered to be probably causative.