図２〜図６の↑は血流のない脾臓組織を示しており，図３〜図５では楔形を呈し，血栓または塞栓による梗塞を示唆する．高熱があり，検査所見でも強い炎症反応を示せば，感染性塞栓（septic emboli）を考慮すべきである．この時点では心雑音は聴取されず，心エコー検査も異常を認めなかった．

2週間の抗生物質投与で解熱し，血液培養ではEnterococcus faecalisが検出された．しかし，3週間目に再び発熱が出現した．
3週間後に2回目の梗塞（図１１〜図１４：▲）を起こした．初回のはかなり小さくなっており（図９〜図１１：↑），抗生物質が効果を発揮した証拠であろう．図５・図６と比較して図１２・図１３で脾臓がやや腫大していることも感染性塞栓症を裏付ける．

抗生物質投与で解熱した，初診から2ヶ月目のCT．
2ヶ月目には2つの梗塞病変がさらに縮小し，治癒に向かっている．

初診から2ヶ月と2週間目に再々度39度台の発熱と悪寒戦慄で来院した．初回同様血液培養でEnterococcus faecalisが検出された．
3回目のかなり大きな梗塞である（図２３〜図２８：△）．この時点で初診時には聴取されなかった心雑音を認め，心エコー検査でも大動脈弁にvegetation（疣贅）が描出され，感染性心内膜炎が原因の感染性梗塞と診断された．脾臓摘出を行った（図A：↑が梗塞部）が，2週間後に敗血症からDICを合併，吐血と喀血を発症し死亡した．病理：脾臓の出血性壊死，球菌のコロニーを認める．

文献考察１）：感染性心内膜炎564例中，27例（2.3%）に脾膿瘍が発生した．弁置換と脾摘が適応（表）
Surgery. 1992 Oct;112(4):781-6; discussion 786-7.
Splenic abscess associated with endocarditis.
Robinson SL, Saxe JM, Lucas CE, Arbulu A, Ledgerwood AM, Lucas WF.

BACKGROUND. Refractory or recurrent sepsis in patients with endocarditis may be from splenic abscess. The purpose of this review is to assess this relationship. METHODS. Of 564 patients treated for documented endocarditis between 1970 and 1990, splenic abscesses developed in 27 patients. The mean age of the 18 men and nine women was 37 years. Etiologic factors included street drugs, dental abscess, and rheumatic fever. Symptoms included fever, myalgia, chills, and dyspnea; the prodrome averaged 2 weeks. Typical signs were heart murmur, left lower-lobe infiltrate, and leukocytosis. Splenomegaly was found in three patients. All patients had valve lesions, which involved the aortic valve alone in 10 patients, the mitral valve alone in eight patients, and multiple valves in nine patients. RESULTS. A splenic defect on computed axial tomographic scan was diagnosed correctly as an abscess in 10 patients, was indeterminant in three patients, and was incorrectly called an infarct in four patients. Thirteen patients died. All 10 patients treated without splenectomy died, including five patients who underwent valvular replacement. In contrast, only three of 17 patients treated by splenectomy with (11 patients) or without (six patients) valvular surgery died. CONCLUSIONS. Splenic abscess often accompanies endocarditis. The diagnosis is suspected by refractory fever and confirmed by abdominal computed axial tomography scan. Splenectomy is warranted before or after valvular surgery, depending on the patient's clinical response to antibiotics.PMID: 1411951

文献考察２）：脾膿瘍（splenic abscess）．67例中死亡率は17.9%.多発性，gram negative bacillusによるもの，APACHE II score>15 は脾摘の適応．
World J Gastroenterol. 2006 Jan 21;12(3):460-4.
Clinical characteristics and prognostic factors of splenic abscess: a review of 67 cases in a single medical center of Taiwan.
Chang KC, Chuah SK, Changchien CS, Tsai TL, Lu SN, Chiu YC, Chen YS, Wang CC, Lin JW, Lee CM, Hu TH.

AIM: To analyze 67 cases of splenic abscess in a medical center of Taiwan during a period of 19 years. METHODS: From January 1986 to December 2004, a total of 67 patients with splenic abscess were enrolled for the retrospective study. The clinical characteristics, underlying diseases, organism spectra, therapeutic methods, APACHE II scores, and mortality rates were analyzed. RESULTS: There were 41 males and 26 females with the mean age of 54.1+/-14.1 years. Multiple splenic abscesses (MSA) account for 28.4% and solitary splenic abscess in 71.6% of the patients. Twenty-six of sixty-seven patients (35.8%) had extrasplenic abscesses, with leading site of liver (34.6%). Microbiological cultures were positive in 58 patients (86.6%), with 71.8% in blood culture and 93.5% in abscess culture. Gram negative bacillus (GNB) infection predominated (55.2%), with leading pathogen of Klebsiella pneumoniae (22.4%), followed by gram positive coccus (GPC) infection (31%). Splenectomy was performed in 26 patients (38.8%), percutaneous drainage or aspiration in 21 (31.3%), and antibiotic therapy alone in 20 patients (29.9%). Eventually, 12 of 67 patients expired (17.9 %). By statistics, spleen infected with GNB was likely to develop multiple abscesses compared with infection with GPC (P=0.036). Patients with GNB infection (P=0.009) and multiple abscesses (P=0.011) experienced a higher mortality rate than patients with GPC infection and solitary abscess. The mean APACHE II score of 12 expired patients (16.3+/-3.2) was significantly higher than that of the 55 survivals (7.2+/-3.8) (P