脳静脈洞血栓症で発症した急性白血病の1剖検例

A CASE REPORT OF ACUTE LEUKEMIA FOLLOWING THE ONSET OF CEREBRAL SINUS THROMBOSIS

　末梢血にleukemic cellが出現せず脳静脈洞血栓症で発症し数日の経過で死亡，剖検にて急性白血病と診断された1症例を経験した。症例は68歳・女性，初診時意識は半昏睡，眼球に振子様運動，体幹・四肢に出血斑を認めた。検査は3.5×10⁴と血小板減少を認めたが血液凝固系に異常はなく白血球は8100／mm³で幼弱細胞は認められなかった。造影CTでempty triangle signを認めた。経過は第3病日脳ヘルニアで死亡した。剖検所見は両側sigmoid sinusに血栓形成を認めた。脳実質は全体的にうっ血，拡張した血管内に多数のleukemic cellを認めるが実質内への浸潤は認めなかった。骨髄はhyper cellularで中型でblasticなmyeloid系の細胞の増加がみられた。急性白血病では播種性血管内凝固症候群に伴う細血管の閉塞が一般的で脳静脈洞血栓症を合併する場合は急性白血病の診断が確定し化学療法中に生じることが一般的である。文献上，木例と同様に脳静脈洞血栓症で発症した報告は2例にすぎない。脳静脈洞血栓症の機序は①静脈洞への白血病細胞の浸潤と，②血液凝固能亢進による血栓形成が考えられる。

A case was reported in which the patient, whose leukemic cells were not found in the peripheral blood, died several days after the onset of cerebral sinus thrombosis, and after the autopsy acute leuke-mia was diagnosed.

The patient, a 68-year-old female, was admitted with clouding of the consciousness. In the initial examinaton, she was semicomatose, pendulum-like movement was seen in the eyeballs, and hemorrha-gic maculae on the trunk and extremities. Among the laboratory findings, WBC was 8, 100 (B 1, St 6, S 77, L 14, Mon 2), RBC 375 × 10⁴, Hb 12.5, Ht 37, PLT 3.5 × 10⁴, PT 15.6, PTT 68, Fib 158, FDP 10 and AT-III 75. In contrast enhanced CT, an empty trianglar sign was observed. On the third hospital day, the patient died of a cerebral hernia. On autopsy, thrombosis was found in the bilateral sigmoid sinus. In the cerebral tissue, congestion was throughout the brain, and many leukemic cellswere seen in the dilated blood vesels, but there was no infiltration into the parencyma. The bone marrow, hypercellular, showed many intermediate type and blastic myeloid cells.

The main neurological complications of leukemia are leukemic infiltration and intracranial hemor-rhages. Capillary obstructions associated with the disseminated intravascular coagulation (DIC) syn-drome are rarely experienced, but obstructions of thick arteries or thick veins such as venous sinuses are seldom seen in general, and most reports of such cases were those resulting from chemotherapy after making a diagnosis of acute leukemia. In the literature, there have been only two reports in our literature. The cases of Jetha and Hazani showed similar results from this type of diagnosis. There are two factors concerning the mechanism of cerebral sinus thrombosis. There are :

①infiltration of leukemic cells into the sinus due to tissue affinity

②thrombosis due to exacerbation of the blood coagulation functions.