Low-grade fibromyxoid sarcoma of the liver: A case report

BACKGROUND Low grade fibromyxoid sarcoma(LGFMS)is a rare and benign mesenchymal tumor with indolent course,most commonly found in young or middle-aged men.The majority of the LGFMSs are located in the trunk and deep soft tissue of the lower extremities.They appear as well circumscribed,although not encapsulated,which often leads to incomplete surgical resection.Despite their seemingly benign appearance,these tumors have aggressive behavior with high metastatic and recurrence rates.Accurate histopathologic examination of the specimen and its immunohistochemical analysis are mandatory for a precise diagnosis.CASE SUMMARY We report a case of a 38 year-old-man who presented with jaundice and upper abdominal discomfort.Multi-detector computed tomography and magnetic resonance imaging showed a large left liver tumor mass,extending to the hepatoduodenal ligament.Left hepatectomy was performed with resection and reconstruction of hepatic artery and preservation of middle hepatic vein.Histopathologic examination confirmed the tumor being a low-grade fibromyxoid sarcoma.Three and a half years after surgery,the patient died after being diagnosed with spine metastasis.CONCLUSION Due to poor response to all modalities of adjuvant treatment,we consider that the focus of treatment should be on surgery as the only option for curing the disease.

Low-Grade Fibromyxoid Sarcoma in the Left Gluteal Region Presenting as Sciatic Nerve Pain

Low-grade fibromyxoid sarcoma is a slowly growing soft tissue neoplasm, mostly affecting young individuals. It usually arises in a deep soft tissue of the lower limbs and trunk, but few cases of low-grade fibromyxoid sarcoma that presents sciatic nerve pain have been reported. We report a 34-year-old woman with a low-grade fibromyxoid sarcoma originating in the left gluteal region that initially presented as sciatic nerve pain;she had experienced this type of pain for 5 years before visiting our hospital. Magnetic resonance imaging revealed a tumor in the left gluteal region. After needle biopsy revealed it to be a low-grade fibromyxoid sarcoma, we performed the wide resection. Intra-operative findings revealed no tumor invasion into the sciatic nerve. No recurrence or metastasis has been detected 6 months post-surgery. Oncologists who encounter patients with sciatic nerve pain should consider the possibility of less common causes such as the low-grade fibromyxoid sarcoma found in our patient.

Low-grade myofibrosarcoma of the maxillary sinus:Two case reports

BACKGROUND Low-grade myofibroblastic sarcoma(LGMS)is an extremely rare tumor characterized by the malignant proliferation of myofibroblasts.LGMS most commonly develops in adults,predominantly in males,in the head and neck region,oral cavity,especially on the tongue,mandible,and larynx.This article presents 2 cases of LGMS localized to the maxillary sinus and provides an overview of the available literature.CASE SUMMARY Two patients with LGMS located in the maxillary sinus underwent surgery at the Department of Head and Neck Surgery.Case 1:A 46-year-old patient was admitted to the clinic with suspected LGMS recurrence in the right maxillary sinus(rT4aN0M0),with symptoms of pain in the suborbital area,watering of the right eye,thick discharge from the right nostril,and augmented facial asymmetry.After open biopsy-confirmed LGMS,the patient underwent expanded maxillectomy of the right side with immediate palate reconstruction using a microvascular skin flap harvested surgically from the middle arm.The patient qualified for adjuvant radiotherapy for the postoperative bed,with an additional margin.Currently,the patient is under 1.5 years of observation with no evidence of disease.Case 2:A 45-year-old man was admitted to our clinic with facial asymmetry,strabismus,exophthalmos,and visual impairment in the right eye.Six months earlier,the patient had undergone partial jaw resection at another hospital for fibromatosis.A contrast-enhanced computed tomography scan revealed a tumor mass in the postoperative log after an earlier procedure.An open biopsy confirmed lowgrade fibrosarcoma(rT4aN0M0).The patient qualified for an extended total right maxillectomy with orbital excision and right hemimandibulectomy with immediate microvascular reconstruction using an anterolateral thigh flap.The patient subsequently underwent adjuvant radiotherapy to the postoperative area.After 9 months,recurrence occurred in the right mandibular arch below the irradiated area.The lesion infiltrated the base of the skull,which warranted the withdrawal of radiotherapy and salvage surgery.The patient qualified for palliative chemotherapy with a regimen of doxorubicin+dacarbazine+cyclophosphamide and palliative radiotherapy for bone metastases.The patient died 26 months after surgical treatment.The cases have been assessed and compared with cases in the literature.CONCLUSION No specific diagnostic criteria or treatment strategies have been developed for LGMS.The treatment used for LGMS is the same as that used for sinonasal cancer radical tumor excision;adjuvant radiotherapy or chemoradiotherapy should also be considered.They have low malignant potential but are highly invasive,tend to recur,and metastasize to distant sites.Patients should undergo regular follow-up examinations to detect recurrence or metastasis at an early stage.Patients should be treated and observed at the highest referral centers.

Anlotinib in combination with pembrolizumab for low-grade myofibroblastic sarcoma of the pancreas: A case report

BACKGROUND Low-grade myofibroblastic sarcoma(LGMS)is a rare spindle cell sarcoma espe-cially in the pancreas,with myofibroblastic differentiation.Hitherto,only a few cases have been reported.CASE SUMMARY Herein,we report a case involving the discovery of a pancreatic mass detected during a routine physical examination.Subsequent imaging and pathological tests of the patient led to the diagnosis of LGMS of the pancreas.Following surgical intervention,the patient experienced recurrence and metastasis.Conventional treatment is not effective for postoperative recurrent pancreatic LGMS with multiple metastases.After communicating with the patients and their families,informed consent was obtained for the treatment of anlotinib combined with pembrolizumab.Evaluation of imaging and clinical symptoms post-treatment revealed a relatively favorable response to the combination of anlotinib and pembrolizumab.CONCLUSION Based on the comprehensive literature review,our report aimed to provide evidence for a better understanding of the disease characteristics,diagnostic criteria,imaging findings,and identification of LGMS.And explore novel treatment strategies for this disease.

Low-grade myofibroblastic sarcoma of the palate

Low-grade myofibroblastic sarcoma （LGMS） is a rare, malignant tumor with myofibroblastic differentiation. Despite it being classified as a distinct entity by the World Health Organization, a few cases were reported in the oral and maxillofacial region. Here, a LGMS developed on the palate of a 73-year-old man who presented with a 1-cm tumor on the posterior border of the palate. Based on the histological and immunohistochemical features, a diagnosis of LGMS was established. The tumor was resected, and no recurrence was observed over 2 years. Although the tongue is the most preferred site for LGMS, it may occur in any region of the oral cavity.

Metastatic low-grade endometrial stromal sarcoma with variable morphologies in the ovaries and mesentery: A case report

BACKGROUND Low-grade endometrial stromal sarcoma(LGESS)classically exhibits a proliferative morphology.However,morphological variation of extrauterine tumors presents a diagnostic challenge.CASE SUMMARY We report the case of a 76-year-old female patient with extensive extrauterine and abdominal neoplastic lesions.Computed tomography showed massive pleural and ascitic fluid,and there was an increase in serum cancer antigen 125.She underwent bilateral adnexectomy and tumor resection.The right ovary had been replaced by a multinodular mass that was 8.5 cm×4.5 cm×3.5 cm in size.In addition,there was a 24 cm×15 cm×13 cm mesenteric mass,which was also multinodular,with local invasion of the intestinal serosa and underlying muscle.Under the microscope,the tumors in different places exhibited two different patterns,thus presenting great challenges to diagnosis and treatment.Thorough pathological assessment eliminated all differential diagnoses in favor of metastatic LGESS derived from a 20-year-old primary tumor initially misdiagnosed as leiomyosarcoma.CONCLUSION LGESS morphology varies according to tumor location.Accurate diagnosis is critical for appropriate treatment and improved prognosis and patient care.

Low Grade Fibromyxoid Sarcomas and Multiple Myeloma in the Same Patient： One Case Report and Literature Review

IntroductionMultiple myeloma （MM） is a neoplastic plasma cell dyscrasia char-acterized by anemia; a monoclonal protein（M-protein） in the serum and/or urine; abnormal bone radiographs and bone pain;hypercal-cemia; and renal insuf.ciency or failure.According to the results of immunoelectrophoresis, patients are separated to Ig type （IgG, IgA, IgD, IgE and IgM）; light chain; nonsecretory.

硬化性上皮样纤维肉瘤和低度恶性纤维黏液样肉瘤的临床病理学特征

目的探讨硬化性上皮样纤维肉瘤(sclerosing epithelioid fibrosarcoma,SEF)及其密切相关的低度恶性纤维黏液样肉瘤(low-grade fibromyxoid sarcoma,LGFMS)的临床病理学特征、长期预后、免疫表型和分子表型。方法回顾性分析11例SEF和5例LGFMS的临床病理资料,行HE及免疫组化染色,分别行FISH检测或高通量测序检测其基因改变,并复习相关文献。结果11例SEF肿瘤细胞呈圆形、卵圆形,细胞形态较为一致,间质可见大量深嗜伊红色的胶原纤维,部分区域细胞稀疏,肿瘤细胞呈条索状或单个夹杂在硬化性间质中,其中1例为杂合性SEF/LGFMS;5例LGFMS镜下由稀疏区和致密区构成,稀疏区间质呈黏液样,可见大量弓形血管,致密区细胞外胶原丰富,两种区域掺杂或交替分布;免疫表型:SEF和LGFMS中MUC4和vimentin均阳性;分子检测显示单纯SEF中90%(9/10)发生EWSR1基因断裂分离,10%(1/10)发生FUS基因断裂分离;1例杂合性SEF/LGFMS伴有FUS-CREB3L2基因融合;LGFMS中均检测到FUS基因断裂分离(5/5)。结论SEF和LGFMS均为低-中度恶性的纤维肉瘤,具有局部侵袭性;MUC4是其特异性标志物;SEF和LGFMS相关的基因突变常为EWSR1或FUS基因,但在发生频率上差异较大;LGFMS、杂合性SEF/LGFMS和SEF可能为一个疾病谱系,而SEF位于谱系的恶性一端,更具侵袭性。

消化道低度恶性纤维黏液样肉瘤6例临床病理分析

目的探讨消化道低度恶性纤维黏液样肉瘤(low-grade fibromyxoid sarcoma,LGFMS)的临床病理学特征和分子学改变。方法回顾性分析6例消化道LGFMS的临床病理学特征、免疫表型和分子改变。采用免疫组化EnVision两步法检测蛋白表达,FISH法检测FUS基因重排情况,RNA-seq法检测FUS融合基因,并复习相关文献。结果6例消化道LGFMS中男性4例,女性2例,患者年龄25~49岁,平均年龄和中位年龄分别为38.3岁和40岁。发生于结肠2例,胃、直肠、小肠和肠系膜各1例。5例为手术标本,肿瘤最大径2~15 cm(平均7.9 cm),1例为穿刺活检标本。低倍镜下见肿瘤多位于消化道壁内,由交替性分布的胶原性区域和黏液样区域组成,两区之间有移行。高倍镜下见瘤细胞形态一致,呈短梭形或卵圆形,核深染,染色质均匀细腻,胞质呈淡嗜伊红色。核分裂象罕见,无坏死。瘤细胞呈长束状、交织状、漩涡状或杂乱状排列。1例肿瘤内见巨菊形团结构,其中央为放射状排列的胶原纤维,周围环绕多层瘤细胞。1例含有硬化性上皮样纤维肉瘤样区域。免疫表型:6例瘤细胞均弥漫表达MUC4,1例弱表达EMA,2例灶性表达DOG1。Ki-67增殖指数为2%~5%。FISH检测4例均显示FUS基因断裂重排,1例RNA-seq检测显示FUS-CREB3L2融合基因。6例均获得随访信息,随访时间8~96个月,5例术后无复发,1例行保守治疗,病情无进展。结论原发于消化道的LGFMS极为罕见,易误诊为消化道其他梭形细胞肿瘤。熟悉其临床病理学特点,辅以免疫组化和分子检测有助于诊断和鉴别诊断。消化道LGFMS多呈惰性经过,应长期随访。

A nomogramfor predicting overall survival in patients with low-grade endometrial stromal sarcoma: A population-based analysis

Background:Low-grade endometrial stromal sarcoma(LG-ESS)is a rare tumor that lacks a prognostic prediction model.Our study aimed to develop a nomogram to predict overall survival of LG-ESS patients.Methods:A total of 1172 patients confirmed to have LG-ESS between 1988 and 2015 were selected from the Surveillance,Epidemiology and End Results(SEER)database.They were further divided into a training cohort and a validation cohort.The Akaike information criterion was used to select variables for the nomogram.The discrimination and calibration of the nomogram were evaluated using concordance index(C-index),area under time-dependent receiver operating characteristic curve(time-dependent AUC),and calibration plots.The net benefits of the nomogram at different threshold probabilities were quantified and compared with those of the International Federation of Gynecology and Obstetrics(FIGO)criteria-based tumor staging using decision curve analysis(DCA).Net reclassification index(NRI)and integrated discrimination improvement(IDI)were also used to compare the nomogram’s clinical utilitywith that of the FIGO criteria-based tumor staging.The risk stratifications of the nomogram and the FIGO criteria-based tumor staging were compared.Results:Seven variables were selected to establish the nomogram for LG-ESS.The C-index(0.814 for the training cohort and 0.837 for the validation cohort)and the time-dependent AUC(>0.7)indicated satisfactory discriminative ability of the nomogram.The calibration plots showed favorable consistency between the prediction of the nomogram and actual observations in both the training and validation cohorts.The NRI values(training cohort:0.271 for 5-year and 0.433 for 10-year OS prediction;validation cohort:0.310 for 5-year and 0.383 for 10-year OS prediction)and IDI(training cohort:0.146 for 5-year and 0.185 for 10-year OS prediction;validation cohort:0.177 for 5-year and 0.191 for 10-year OS prediction)indicated that the established nomogram performed significantly better than the FIGO criteria-based tumor staging alone(P<0.05).Furthermore,DCA showed that the nomogram was clinically useful and had better discriminative ability to recognize patients at high risk than the FIGO criteria-based tumor staging.Conclusions:A prognostic nomogram was developed and validated to assist clinicians in evaluating prognosis of LG-ESS patients.

低度恶性纤维黏液样肉瘤2例报道及文献复习

目的 探讨低度恶性纤维黏液样肉瘤 (LGFS)的临床病理特点、诊断和预后。方法 对 2例LGFS进行光镜、电镜、组化和免疫组化观察并结合文献进行分析。结果 肿瘤由纤维性区和黏液样区混合构成 ,二者呈交错相间排列 ;纤维性区瘤细胞呈旋涡状排列 ;黏液样区瘤细胞散在 ;细胞核轻度异型 ;PAS染色黏液样区和肿瘤细胞浆内均为阴性。免疫组化标记vimentin、NSE阳性。电镜观察瘤细胞呈纤维母细胞与肌纤维母细胞的特点。结论 LGFS是一种来源于纤维母细胞独立存在进展缓慢的低度恶性软组织肉瘤 ,易误诊为良性。病理诊断依赖于组织学、免疫组化和电镜观察 。

低度恶性纤维黏液性肉瘤一例并文献复习

目的:分析低度恶性纤维黏液样肉瘤的临床病理特征及鉴别诊断。方法:对一例低度恶性纤维黏液样肉瘤进行大体、光镜及免疫组化观察并结合文献复习。结果:瘤细胞排列呈漩涡状,散布在富于血管的纤维黏液样间质中,黏液区与纤维区明显过渡。免疫组化肿瘤细胞SMA(-)、EMA(-)、S-100(-)、CD99(-)、CD68(-)。结论:低度恶性纤维黏液样肉瘤是一种非常少见的软组织肿瘤,常被误诊为良性肿瘤,需与黏液样纤维肉瘤Ⅰ级、黏液样神经纤维瘤、恶性纤维组织细胞瘤等鉴别诊断。

四肢躯干低度恶性纤维黏液肉瘤与黏液纤维肉瘤的临床病理比较分析

目的探讨发生在躯干肢体5例低度恶性的纤维黏液肉瘤(low-grade fibromyxoid sarcoma,LGFMS)和4例黏液纤维肉瘤(myxofibro sarcoma,MFS)的临床病理特征、生物学行为、诊断和鉴别诊断。方法分析5例LGFMS的临床病理资料、大体形态、组织学特点、免疫组化标记和预后,并与4例MFS相比较。结果两类肿瘤能够在组织形态学方面进行鉴别,LGFMS由梭形细胞构成,具有黏液区和纤维间质交替分布的特点。肿瘤细胞无异型性,肿瘤组织无坏死。MFS以细长弯曲的薄壁血管和脂母细胞样细胞为特征,伴有丰富的黏液区而没有大面积的实性区,有肿瘤性坏死。两类肿瘤在免疫组化标记、肿瘤位置和患者的年龄方面也有差别。结论LGFMS是一种罕见肿瘤,临床病理及生物学行为与MFS不同,二者可以通过临床病理特点进行鉴别,LGFMS较之MFS有更好的预后。

罕见部位低度恶性纤维黏液样肉瘤3例临床病理观察

目的探讨低度恶性纤维黏液样肉瘤（LGFMS）的临床病理特征及鉴别诊断。方法收集3例发生于罕见部位的LGFMS，对其临床表现、影像学特点、组织学特征、免疫组化及预后进行分析。结果3例LGFMS分别发生于上颌翼腭窝、乳腺和腹膜后。肿瘤边界清楚，包膜完整，最大直径3～7cm；切面灰白、灰红色，局部区域有黏液。镜下见肿瘤组织由纤维母细胞构成，细胞密集区和细胞稀疏区交替排列，其间过渡突然。细胞密集区间质胶原纤维丰富，稀疏区间质黏液样变，可见较多鸡爪样或树枝状管腔闭合的毛细血管。肿瘤细胞形态温和，胞核无明显异型，核分裂象罕见。免疫组化：肿瘤细胞MUCA特异性（＋）。发生于上颌翼腭窝病例术后3年局部复发，发生于腹膜后和乳腺的病例分别随访5年和2年均无瘤生存。结论LGFMS因细胞形态温和及组织形态多样性极易误诊为其他具有黏液样间质的梭形细胞肿瘤。该瘤发病部位广泛，最常见于年轻人；其生物学行为呈惰性经过，治疗上对肿瘤作局部切除已足够。

低度恶性纤维粘液样肉瘤电镜观察

目的 :研究低度恶性纤维粘液样肉瘤 ( low- grade fibromyxoid sarcoma,L GFS)的超微结构特点。方法 :对两例 LGFS进行电子显微镜观察 ,并与文献报道比较。结果 :瘤细胞多呈长梭形或不规则形 ,部分细胞表面见丝状假足样突起 ,核膜光滑 ,或核形不规则呈分叶状 ,核染色质呈细块状 ;大部分瘤细胞胞浆内含丰富的扩张的粗面内质网 ,细胞周围见丰富的胶原纤维 ,部分瘤细胞之间可见桥粒样连接 ,胞浆内见肌微丝并见密斑 ,此外尚见胞浆内神经内分泌颗粒、核内假包涵体样结构、胞浆内长棱形的类似结晶体样的结构及被膜清楚的脂质空泡。讨论 :L GFS瘤细胞显示纤维母细胞和肌纤维母细胞的超微结构特征 ,在肿瘤超微病理诊断和鉴别诊断中有重要价值。

低度恶性纤维黏液样肉瘤3例临床病理分析

目的探讨低度恶性纤维黏液样肉瘤（LGFMS）的临床病理学特征。方法对3例低度恶性纤维黏液样肉瘤的临床资料、病理形态学、免疫组织化学染色进行分析。结果3例均为男性,年龄18～43岁,平均31岁。肿瘤分别位于大腿、腹壁及前臂。最大径3～5 cm。镜下,肿瘤组织由少量形态温和的梭形细胞构成,间质胶原沉积,可见纤维区和不规则黏液区彼此移行。3例肿瘤细胞均vimentin（＋）,Ki-67〈2%,S-100、SMA、MSA、desmin、caldesmon、CD34和bcl-2均（-）。例1失访,例2和例3分别随访2年和1年均未见复发。结论低度恶性纤维黏液样肉瘤是一种少见的软组织肿瘤,具有良性组织学特点。鉴别诊断包括低度恶性黏液纤维肉瘤、黏液样脂肪肉瘤、纤维瘤病、黏液性神经纤维瘤、黏液样隆突性皮肤纤维肉瘤、炎性肌纤维母细胞瘤、黏液性恶性纤维组织细胞瘤等肿瘤。

低度恶性纤维黏液样肉瘤临床病理分析

目的:探讨低度恶性纤维黏液样肉瘤(low-grade fibromyxoid sarcoma,LGFMS)的临床病理特征和诊断要点。方法:分析3例LGFMS的临床资料,观察组织学形态、免疫表型及分子病理检测结果,讨论鉴别诊断并复习相关文献。结果:患者均为女性,中位年龄57岁,肿瘤分别位于右侧膝关节前方、右侧乳腺和左侧上颌窦。肿块最大径为2.2~10.0 cm,边界欠清,似有包膜,切面灰白,部分区域呈半透明状,质中有黏液感。镜下见肿瘤组织主要由梭形纤维母细胞样细胞构成,包括两种形态区域,其一为细胞稀疏的胶原样区域;其二为细胞相对较丰富的黏液样区域。肿瘤组织中可见较多弓形血管并伴有血管周玻璃样变性。瘤细胞形态温和,无明显异型性,核分裂象罕见。免疫组织化学染色结果示:vimentin,MUC4,CD99及bcl-2阳性表达,SMA,desmin,S100,CD34,ALK及myogenin阴性表达。发生于右侧乳腺的病例行荧光原位杂交(fluorescent in situ hybridization,FISH)检测,检出FUS基因易位。发生于右侧膝关节和乳腺的2个病例分别随访20个月和51个月,患者均无瘤生存。发生于左侧上颌窦的病例于手术后12个月死亡。结论:LGFMS常见于年轻人,但各年龄段患者均可受累。好发部位为下肢近端和躯干,少见于头颈部和乳腺。LGFMS具有温和的多样性的组织学形态,容易误诊为具有黏液样结构的其他梭形细胞肿瘤。LGFMS具有转移和复发的恶性生物学行为,治疗上需对肿块作完整切除并长期随访观察。

左上颌窦低度恶性纤维黏液样肉瘤1例并文献复习

目的:报道1例左上颌窦低度恶性纤维黏液样肉瘤探讨其临床病理特点、诊断和鉴别诊断。方法:对1例左上颌窦低度恶性纤维黏液样肉瘤进行光镜和免疫组化检查,并结合文献讨论。结果:肿瘤分两个区域:胶原化区域和黏液样区域,两种区域交替排列,瘤细胞为梭形或不规则形,染色质呈细块状,偶可见核仁。免疫表型:肿瘤细胞AE1/AE3、EMA、CK、ACT、LCA、CD1α、S-100均阴性,SMA、CD68局灶性阳性,LYS弱阳性,Vim、CD163、CD45RO阳性。结论:低度恶性纤维黏液样肉瘤是一种罕见的低度恶性肿瘤,诊断和鉴别诊断主要依赖其病理形态学特点并结合免疫表型。

低度恶性纤维粘液样肉瘤临床病理研究

目的认识低度恶性纤维粘液样肉瘤临床特点和病理诊断及鉴别诊断。方法对１７例低度恶性纤维粘液样肉瘤进行临床、病理及免疫组化分析，并随访观察。结果男１０例，女７例，年龄３～７２岁（平均４３．２岁）。病变部位：下肢１０例（其中大腿９例），背部２例，肘部、胸部、颈部、腹股沟和腹膜后各１例。肿瘤直径２．１～１３．５ｃｍ不等，平均７．６ｃｍ。光镜下：瘤细胞小，梭形或星形，核深染有轻度异形，核分裂不常见。组织学特征为：轻至中度丰富细胞的纤维粘液样区和呈漩涡状排列的梭形细胞区在同一肿瘤中交替出现。免疫组化染色，肿瘤细胞波形蛋白阳性。７例有随访结果。结论低度恶性纤维粘液样肉瘤是一种独立存在。

低级别纤维黏液样肉瘤4例临床病理分析

目的 探讨低级别纤维粘液样肉瘤的临床病理特征,诊断和鉴别诊断的要点。方法 对4例低级别纤维粘液样肉瘤进行临床特征和病理学分析,结合文献分析其诊断要点和鉴别诊断。结果 4例患者,男性3例,女性1例,年龄26~70岁,肿瘤分别位于左颈后部,左臀部,左腹股沟及胸壁。组织学上,由形态较温和的短梭形或卵圆形细胞组成,间质呈典型的粘液样与胶原样交替分布。肿瘤细胞表达Vimentin, MUC4。结论 低级别纤维粘液样肉瘤是纤维肉瘤的一种特殊亚型,好发于青年人,通过病例回顾和文献学习掌握这一较少见肿瘤的诊断和鉴别诊断十分必要。