皮肤基本病理改变.ppt

1、皮肤疾病基本病理改变,一、皮肤疾病的临床表现,1、斑疹：Macule,斑疹：境界清楚的扁平损害，与周围正常皮肤颜色不同。斑疹的大小与形态多样：A色素沉着hyperpigmentation (A)色素减退hypopigmentation真皮色素沉着dermal pigmentation (B)毛细血管扩张红斑 (erythema) (C)紫癜purpura (D)鳞屑疹：斑疹表面伴有细小鳞屑，如花斑癣tineaB. 红色斑疹压之退色，因毛细血管扩张之故。图为药物反应性皮疹。,2、丘疹：Papule,丘疹是高起于皮面的实性损害，直径小于1cm。原因：真皮代谢物质沉积：淀粉物质、粘蛋白 (A) 局灶

2、炎细胞浸润(B) 真皮或表皮细胞增生(vegetation) (C) 丘疹表面伴有鳞屑形成鳞屑性丘疹，如银屑病psoriasis. B. 真皮内细胞增生，如真皮黑色细胞痣dermal melanocytic nevi; C. 多发性、境界较清、大小不等但呈相互融合的丘疹，表面扁平、反光。见于lichen planus（扁平苔癣）。,3、斑块：Plaque,A. 斑块：绘图状的大面积高起于皮肤的损害。B. 境界清楚、暗红色的鳞屑性斑块，中心可退缩，常见于寻常性银屑病。C. 苔癣样变Lichenification：皮肤明显增厚，常见于反复搔痒与摩擦。见于遗传性过敏性皮炎、湿疹性皮炎、结节性痒疹。表

3、面可见抓痕、剥脱和血痂。,4、结节：Nodule,A. 皮肤可触性的实性圆形或椭圆形损害，通常直径大于1cm。（A）结节伸入真皮与皮下脂肪组织，（B）结节位于表皮。 B. 境界清楚的实性结节，周围表面光滑，中心凹陷，形成溃疡，中心血管扩张，图为结节性基底细胞癌 (nodular basal cell carcinoma)。 C. 皮下多发性大小不等的结节，图为黑色素瘤转移 (melanoma metastases)。,5、风团：Wheal,圆形或扁平的丘疹或斑块，迅速消失或数小时内消失。直径可为34 mm如cholinergic urticaria （胆碱能性荨麻疹） (B)。 过敏性病变大而

4、相互融合，常见于青霉素、其它药物或花粉、尘螨过敏 (C)。 荨麻疹常伴明显搔痒。,6、小疱与大疱：Vesicles and bullae,小疱与大疱通称为水疱blisters。 通常境界清楚，内含液体。小疱直径0.5cm。(A). 角层下水疱(B). 海绵状水疱：细胞间水肿。 水疱直径0.5cm称为大疱。下图示临床图片，水疱透亮，易破萎陷，表面结痂，图为脓疱疮staphylococcal impetigo。病人直立时，水疱下坠，乃因白细胞向下沉积。,6.1、表皮内水疱,(A) 细胞间连接溶解(B) 病毒感染致表皮细胞气球样变，如varicella-zoster（水痘带状疱疹病毒） 带状疱疹he

5、rpes zoster 沿皮神经分布，串珠状的水疱。水疱中心凹陷，称为脐凹征。轻压水疱，水疱向周围扩张并增大，称为Nikolsky征阳性。常见于寻常型天疱疮。,Nikolskys sign,6.2、表皮下水疱,Subepidermal vesicles, as shown in the drawing (A), occur as a consequence of pathologic changes in the region of the dermal-epidermal junction. Subepidermal vesicles and bullae are seen in bullo

6、us erythema multiforme(大疱性多形红斑), porphyria cutanea tarda （迟发性皮肤卟啉病）, epidermolysis bullosa（大疱性表皮松解症）, dermatitis herpetiformis（疱疹样皮炎）, and bullous pemphigoid（大疱性类天疱疮）. The clinical photograph (B) demonstrates bullae in the latter condition. Some of them arise on normal and some on erythematous skin.

7、 Most of them are tense and filled with a serous or hemorrhagic fluid; some have collapsed and crusted.,7、糜烂：Erosion,表皮细胞部分或全部缺失，遗留境界清楚的湿润状损害，称为糜烂。可继发于水疱或大疱表皮脱失。也可继发于epidermal necrosis as in toxic epidermal necrolysis（中毒性表皮坏死性松解症），痊愈后不留疤痕。Why？,8、脓疱：Pustule.,含有脓性渗出液的水疱称为脓疱。 原发性非毛囊性损害的脓疱常见于pustular ps

8、oriasis（脓疱性银屑病），脓疱表浅，相互融合，形成脓湖。还见于掌跖脓疱病，角层下脓疱性皮炎，也可继发于水疱的感染。,9、囊肿：Cyst.,囊性结构包裹液体或半固体物质（液体、细胞或细胞产物）呈球形或椭圆形结节或丘疹改变，但有弹性，能自动回复，状如眼球。最常见于epidermal cysts (表皮囊肿，A)、pilar cysts (毛发囊肿，B). 临床图片：浅蓝色的弹性囊肿，为cystic hidradenoma，（囊性汗腺瘤），其内充满粘液样物质。,10、萎缩：Atrophy.,皮肤减少或变薄，可局限于表皮或真皮，或二者兼有。(A). 表皮萎缩epidermal atrophy(B

9、). 表皮真皮均萎缩变薄。 真皮萎缩时真皮乳头层或网状层变薄，皮肤下陷。皮下脂肪组织萎缩也致皮肤下陷，皮纹消失，皮肤变薄，表面起皱纹。,11、溃疡：Ulcer.,An ulcer, shown in (A), is the hole or defect that remains after an area of epidermis and at least part of the dermis have been destroyed or removed. Because the dermis is involved, ulcers heal with scarring. The clinic

10、al photograph (B) shows a gigantic ulcer with a red, granulating base and well-defined, punched-out borders.,12、疤痕：Scar.,A scar is the fibrous tissue replacement that develops as a consequence of healing at the site of a prior ulcer or wound. A scar may be hypertrophic (A) or atrophic (B), as shown

11、in the drawing (A). A typical clinical example of a hypertrophic scar is shown in the photograph (B).,13、脱屑：Desquamation.,Abnormal shedding or accumulation of stratum corneum in perceptible flakes is called scaling and is shown in the drawing (A). Parakeratotic（角化不全） scale (with retained nuclei) may

12、 be seen surmounting psoriasiform epidermal hyperplasia (A，银屑病样表皮增生).Densely adherent scale with a gritty feel from a localized increase in the stratum corneum is seen in actinic keratoses (B，光化性角化症). Typical psoriatic scaling is shown in the photograph (B). Scales that adhere tightly to the underly

13、ing epidermis may build up to form an asbestos-like layer that obscures the underlying lesion, as in the psoriatic plaque （银屑病斑块）shown in (C).,14、痂： Crusts,Crusts result when serum, blood, or purulent exudate dries on the skin surface and are characteristic of injury and pyogenic infections.Crusts m

14、ay be thin, delicate, and friable (A) or thick and adherent (B), as shown in the drawing (A). Crusts are yellow when formed from dried serum, green or yellow-green when formed from purulent exudate, or brown or dark red when formed from blood. Superficial crusts that occur as honey-colored, delicate

15、, glistening particulates on the surface are typical of impetigo （脓疱病）and are illustrated in the photograph (B).,二、皮肤活检,适应症：确定诊断与了解病情有高度诊断价值：肿瘤、病毒性皮肤病（传染性软疣、带状疱疹、寻常疣）、角化性皮肤病（毛囊角化病、汗管角化病等）、红斑鳞屑性皮肤病（银屑病、扁平苔藓等）、真菌性皮肤病（孢子丝菌病、马拉色菌性毛囊炎、着色芽生菌病）有诊断价值：疱疹类皮肤病（天疱疮、家族性良性天疱疮）、代谢性皮肤病（原发性皮肤淀粉变性、胫前粘液水肿）、某些肉芽肿性皮肤病（环

16、状肉芽肿、面部肉芽肿、结节病）、部分风湿病（红斑狼疮、硬皮病、结节性动脉炎）无明显特征，需结合临床排除的皮肤病：结核、麻风,皮肤活检要求,充分发育的损害性病变，早期病变非特异性，晚期已恢复、变性、坏死、疤痕水疱性皮肤病选择早期损害选择活动性损害的周边部组织：如色素性皮肤病、银屑病进展期标本必须含有皮下脂肪组织，因部分皮肤病仅限皮下脂肪组织病变取材应含少量正常皮肤，避免腋窝、腹股沟等摩擦部位尽量避免面部、关切活动部位取材老年患者、血液淤积患者避免下肢取材,三、皮肤病基本病理改变,病变观察要求表浅部（表皮与真皮乳头层）观察：表皮表皮真皮接合带真皮乳头层表浅小血管网状层观察：结缔组织附属器真皮深层血

17、管丛皮下组织观察：脂肪小叶脂肪间隔,病理医生观察皮肤活检注意事项,紧密结合临床：皮疹、生化检查、实验室检查、影像学检查；病人年龄、性别、个人生活史值得参考等。时刻留心病人的全身状况。尽可能参考临床医生意见，需主动与其交流。必要时观察病人皮疹状态、摸淋巴结、亲自询问病史再行决断。组织化学染色有助于寻找病原体、组织变性性疾病，免疫组化有助于淋巴瘤与良性淋巴组织增生疾病的鉴别。儿童患者应仔细了解免疫状态，排除原发性免疫缺陷性疾病。,（一）表皮病变1、角化过度：Hyperkeratosis,角层增厚，角层细胞完全角化，无残留细胞核。角层增厚：扁平苔癣、掌跖角化病、鱼鳞病、花斑癣、红斑狼疮。伴有毛囊漏斗角质栓：毛囊角化病伴有汗孔角质栓：汗孔角化病,2、角化不全：parakeratosis,表皮角层细胞保留固缩的细胞核。常见于银屑病。,