雙語(yǔ)病例丨原發(fā)性骨平滑肌肉瘤（XMRPET）

雙語(yǔ)病例丨原發(fā)性骨平滑肌肉瘤（XMRPET）History:

A43-year-oldwoman

presentswithkneepainafterfeelingapoppingsensationwhileplayingtennis.病史：43歲女性，打網(wǎng)球時(shí)感覺到砰的感覺，膝部疼痛。Radiographswereobtained.平片如下所示。問答：Thereisalesionintheproximaltibiawithabenignappearance.TrueFalse

(correct!)脛骨近端病灶呈良性表現(xiàn)。答：錯(cuò)誤。Thelesionintheproximaltibiahasaggressivefeatures,includinganinfiltrativeappearanceandill-definedmargins.脛骨近端病灶有侵襲性，呈浸潤(rùn)性表現(xiàn)，邊界模糊。MRimagesAnMRIscanofthekneewasperformed.Intravenouscontrastwasnotadministeredduetoacutekidneyinjury.CoronalT1-weightednonfat-saturatedand

T2-weightedfat-saturatedimagesareshownbelow.行膝關(guān)節(jié)MR掃描。由于急性腎損傷未行增強(qiáng)掃描。冠狀T1WI非壓脂及T2WI壓脂圖像如下所示。問答Whatisthenextstep?

下一步該做什么？Short-termimagingfollow-up短期隨訪Noadditionalfollow-uprequired無(wú)需隨訪Biopsy

(correct!)

活檢（正確答案）AdditionalquestionsBiopsyofthetibiallesionrevealedapathologicdiagnosisofleiomyosarcoma.脛骨病變活檢，病理診斷為：平滑肌肉瘤。Primaryboneleiomyosarcomasarecommonprimarybonemalignancies.TrueFalse

(correct!)原發(fā)性骨平滑肌肉瘤是常見的原發(fā)性骨惡性腫瘤。（說法錯(cuò)誤）Whichofthefollowingismorelikely?下列那種情況最可能？Primaryboneleiomyosarcoma原發(fā)性骨平滑肌肉瘤Leiomyosarcomametastasistobone

(correct!)平滑肌肉瘤轉(zhuǎn)移至骨骼（正確）PelvicMRimagesAnMRIscanofthepelviswasperformed.SagittalandaxialT2-weightedimagesareshown.盆腔MR圖像：行盆腔MR掃描，矢狀及軸位T2WI圖像如下所示。Theuterinefindingsarehighlysuspiciousforuterineleiomyosarcoma.TrueFalse

(correct!)子宮的表現(xiàn)應(yīng)高度懷疑為子宮平滑肌肉瘤（說法錯(cuò)誤）。Therearetypicalfindingsofsmallbenignleiomyomas.However,smallleiomyosarcomascanhavethesameappearanceasbenignleiomyomas.為小良性平滑肌瘤的典型表現(xiàn)，然而，小的平滑肌肉瘤可能與良性平滑肌瘤有著同樣的表現(xiàn)。PET/CTimagesAwhole-bodyFDG-PET/CTscanwasperformed.FusedCT/PETimagesareshown(axialpelvisandcoronalknees).

行全身PET/CT，CT/PET融合圖像如下所示（盆腔軸位、膝部冠狀）TherightproximaltibiallesionshowsavidFDGuptake.True

(correct!)False右脛骨近端病灶可見明顯FDG攝?。ㄕf法正確）。TheuterusshowsalesionwithavidFDGuptake.TrueFalse

(correct!)子宮病灶可見明顯FDG攝?。ㄕf法錯(cuò)誤）。AdditionalquestionsBecauseuterineleiomyosarcomasaremuchmorecommonthanprimaryboneleiomyosarcomas,thepatientunderwentahysterectomytoevaluateforaprimaryuterineleiomyosarcoma.Onpathologicevaluation,theuterushadonlybenignfindings.其他問題由于子宮平滑肌肉瘤比原發(fā)性骨平滑肌肉瘤更常見，患者接受了子宮切除術(shù)以評(píng)估是否為原發(fā)性子宮平滑肌肉瘤。最后病理診斷只有良性發(fā)現(xiàn)，為子宮平滑肌瘤。Primaryboneleiomyosarcomashaveadistincthistologicappearancetoleiomyosarcomasarisingfromothersites.TrueFalse

(correct!)原發(fā)性骨平滑肌肉瘤與其他部位的平滑肌肉瘤有不同的組織學(xué)表現(xiàn)（說法錯(cuò)誤）。Primaryboneleiomyosarcomasmostcommonlyoccurinthespine.TrueFalse

(correct!)Theymostcommonlyoccurintheappendicularskeleton.原發(fā)性骨平滑肌肉瘤最常見于脊柱（說法錯(cuò)誤），最常見于四肢骨。Primaryboneleiomyosarcomashaveadistinctradiologicappearancewhencomparedwithotherprimarybonesarcomas.TrueFalse

(correct!)與其他原發(fā)骨肉瘤相比，原發(fā)性骨平滑肌肉瘤有著不同的影像學(xué)表現(xiàn)（說法錯(cuò)誤）。FindingsRadiographs:

Locatedcentrallywithintheproximaltibiaisaninfiltrative

mixedscleroticandlyticlesion,whichappearstohavecorticalbreakthroughalongthetibialplateau.KneeMRI:

AlargeinfiltrativelesionispresentwithintheproximaltibiathathasreplacedthenormalfattymarrowandhasintrinsicT1signalisointensetomuscle.OntheT2-weightedimage,thelesionhasheterogeneouslyhighintrinsicT2signal.PelvicMRI:

T2

hypointenselesionsarepresentarisingfromtheuterinemyometrium,mostconsistentwithbenignleiomyomas.FDG-PET/CT:

AvidFDGuptakeisseenwithintheproximalrighttibiallesion.Noabnormaluptakeisseenwithinthepelvis.Althoughimagesarenotshown,nootherabnormalFDGuptakeisseenintheremainderofthebody.影像表現(xiàn)：平片：脛骨近端中心性的浸潤(rùn)性的硬化和溶解混合性病變，病變突破了脛骨平臺(tái)骨皮質(zhì)。膝關(guān)節(jié)MRI：近端脛骨內(nèi)較大的浸潤(rùn)性病變，已經(jīng)取代了正常的脂肪骨髓，T1WI上與肌肉等信號(hào)，T2WI上呈不均勻高信號(hào)。盆腔MRI：子宮肌層內(nèi)T2低信號(hào)灶，與良性平滑肌瘤的表現(xiàn)最為一致。FDG-PET/CT：在右側(cè)脛骨損傷部位可見FDG攝取。骨盆內(nèi)未見異常攝取。盡管沒有顯示圖像，但在身體的其余部分沒有看到異常的FDG攝取。DifferentialdiagnosisPrimaryboneleiomyosarcomaMetastasisMultiplemyelomaPrimarybonesarcomaLymphoma鑒別診斷：原發(fā)性骨平滑肌肉瘤轉(zhuǎn)移瘤多發(fā)性骨髓瘤原發(fā)性骨肉瘤淋巴瘤Diagnosis:

Primaryboneleiomyosarcoma(pathology-confirmed)最后診斷：原發(fā)性骨平滑肌肉瘤（病理證實(shí)）Discussion

討論P(yáng)rimaryboneleiomyosarcoma

(PBL)原發(fā)性骨平滑肌肉瘤（PBL）PathophysiologyandepidemiologyPrimaryboneleiomyosarcomas

areextremely

rareprimaryosseousmalignancies,withfewerthan200casesreportedintheliterature.Onlycasereportsandsmallcaseserieshavebeenreported,makingcommentsonepidemiologysomewhatdifficult.Thesetumorsoccurinadults,withconflictingreportsonanagepredilection.Thereappearstobeanequaldistributionbetweensexes.Theymostcommonlyoccurintheappendicularskeleton.Pathologically,primaryboneleiomyosarcomasarethoughttoarisefromintraosseousbloodvesselsorpossiblyintraosseouspluripotentmesenchymalstemcells.Theyareatypeofspindlecellbonesarcoma.Interestingly,theyarehistologicallyidenticaltoprimaryleiomyosarcomasarisinginothersitesinthebody(uterus,retroperitoneum,etc.).

Thesetumorsaresorarethatwhenencounteredtheyarelikelyclassifiedasothertypesofprimarybonesarcomas(i.e.,undifferentiatedpleomorphicsarcoma,fibrosarcoma,etc).Also,giventheirrarity,othermorecommonsitesofleiomyosarcoma(gynecologic,retroperitoneum,softtissues)mustfirstbeexcluded.病理生理學(xué)和流行病學(xué)原發(fā)性骨平滑肌肉瘤是非常罕見的原發(fā)性骨惡性腫瘤，文獻(xiàn)報(bào)道少于200例，只有病例報(bào)告和小病例系列報(bào)道，使流行病學(xué)評(píng)論有些困難。這些腫瘤發(fā)生在成年人身上，有關(guān)年齡偏好的報(bào)道相互矛盾。男女發(fā)病率基本持平。腫瘤最常見于附肢骨骼中?！±砩希l(fā)骨平滑肌肉瘤被認(rèn)為是由骨內(nèi)血管或骨內(nèi)多能間充質(zhì)干細(xì)胞產(chǎn)生的。是一種梭形細(xì)胞骨肉瘤。有趣的是，它們?cè)诮M織學(xué)上與體內(nèi)其他部位（子宮，腹膜后等）中產(chǎn)生的原發(fā)性平滑肌肉瘤相同。這些腫瘤非常罕見，?？赡鼙粴w類為其他類型的原發(fā)性骨的肉瘤（即未分化的多形性肉瘤，纖維肉瘤等）。此外，鑒于其稀有性，首先必須排除其他更常見的平滑肌肉瘤（婦科、腹膜后、軟組織）。ClinicalpresentationClinically,mostpatientspresentwithpain.Asignificantproportionofpatientsalsopresentwithpathologicfracture.

臨床表現(xiàn)臨床上大多數(shù)患者表現(xiàn)出疼痛。相當(dāng)一部分患者也存在病理性骨折。ImagingfeaturesRadiographs：Onradiographs,primaryboneleiomyosarcomasaregenerallyosteolyticlesionswithaggressivefeatures,includingirregularandinfiltrativemarginsandapermeativeappearance.Corticalerosionsandbreakthroughcanoccur.Theygenerallyarisefromthemetaphysisbutcanextendintoboththeepiphysisanddiaphysis.CT：CTfindingsaresimilartoradiographicfindings,withtheexceptionthatcorticalinvolvementisbetterevaluated.MRI：MRfindingsaregenerallynonspecific,withintrinsicT1signaloftensimilartomuscleandintrinsicT2signalthatisoftenheterogeneouslyhigh.影像表現(xiàn)：X線片：原發(fā)骨平滑肌肉瘤一般表現(xiàn)為具有侵蝕性特征的溶骨性病變，包括不規(guī)則的形態(tài)、浸潤(rùn)性的邊緣，以及滲透性的表現(xiàn)，可出現(xiàn)皮質(zhì)侵蝕和突破。它們通常起源于干骺端，但可以延伸到骨骺和骨干。CT：CT表現(xiàn)與X線相似，不同之處在于能更好地評(píng)估骨皮質(zhì)受累的情況。MRI：MR表現(xiàn)一般無(wú)特異性，其內(nèi)T1信號(hào)通常與肌