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这个病例极少见。肿瘤由不规则分枝状的增生性薄壁血管组成 ,增生性的血管在真皮的全层内呈浸润性生长。部分内皮细胞略肿胀 ,但细胞无异型性 ,也无核分裂象。多数血管内皮细胞的外围可见梭形的血管周细胞。血管之间的基质伴有不同程度的胶原样变性。

这样描述一下，大概有诊断方向了。

 Diagnosis:
Microvenular hemangioma
Discussion
Microvenular hemangioma was first described by Hunt in 1991 (J Cutan Pathol 1991;18:235).  It is rare, with less than 50 cases reported.  It presents as a slow growing, solitary, asymptomatic, purple-red papule or plaque in young to middle-aged adults, often on the trunk or limbs.  The histology shows a dermal proliferation of small, irregular branching capillaries and venules with inconspicuous lumina.  Endothelial cells may be plump, but no atypia is present.  The stroma is collagenous.  No spindle cells are present.
The endothelial cells are immunoreactive for CD34 and Factor VIII related antigen.  Smooth muscle actin highlights pericytes surrounding the endothelial cells.
The main differential diagnosis is patch stage Kaposi's sarcoma, which also has irregular vascular spaces.  However, they are anastomosing and not collapsed, and are accompanied by atypical endothelial cells, eosinophilic hyaline globules, plasma cells and fascicles of spindle cells.  There may be irregular dissection of collagen bundles by vessels.  The spindle cells are HHV8 positive (Am J Clin Pathol 2004;121:335), and the patients are HIV positive, which is usually helpful.  However, there was a recent report of HHV8 positive microvenular hemangioma (image-see fig c, d) in an unusual case of POEMS syndrome (Arch Pathol Lab Med 2003;127:1034)
Kaposiform hemangioendothelioma also has slit-like lumina, although they are due to nodules and sheets of compact spindle cells.  It affects the skin or retroperitoneum of infants and children, and may be associated with severe coagulopathy.
Microvenular hemangioma is a benign lesion.  To date, excision appears to be curative.
Case reports: 40 year old woman (Dermatology 2003;206:161), 23 year old Japanese woman (Pathol Int 1998;48:237)

 诊断:
微静脉型血管瘤
讨论
微静脉型血管瘤最初由Hunt于1991描述(J Cutan Pathol 1991;18:235)。罕见，报道总数不足50例。呈一种缓慢生长的、孤立的、无症状的、紫红色丘疹或斑块，见于年轻到中年成人，多位于躯干或四肢。
组织学显示真皮内小、不规则分支状毛细血管和小静脉的增生，伴不明显的血管腔隙。可有内皮细胞肿胀，但无不典型性。间质胶原化。无梭形细胞出现。
内皮细胞呈CD34+和VIII因子相关抗原+。SMA染色可突出显示内皮细胞周围的外膜细胞(毛细血管)。
主要鉴别诊断是斑片期Kaposi肉瘤，它也有不规则血管腔隙。然而，它们的血管网是吻合的，不塌陷，伴不典型内皮细胞、嗜碱性玻璃样小球、浆细胞和梭形细胞束。可有血管分割的不规则胶原束。梭形细胞呈HHV8+(Am J Clin Pathol 2004;121:335),且患者HIV+，有助于诊断。然而，也有一个最近报道了HHV8+的微静脉型血管瘤(见图c, d)，发生于一种少见的POEMS病例(Arch Pathol Lab Med 2003;127:1034)。
Kaposi型血管内皮瘤也有裂隙样腔隙，尽管它们是由于致密的结节状或成片梭形细胞受挤压所致。它累及婴儿和儿童的皮肤或后腹膜，可能与急性凝血功能紊乱有关。
微静脉型血管瘤是良性病变。至今，肿块切除似乎可治愈。病例报道：40岁女性(Dermatology 2003;206:161), 23岁日本女性(Pathol Int 1998;48:237)

 
对照翻译如下：
Microvenular hemangioma was first described by Hunt in 1991 (J Cutan Pathol 1991;18:235).
微静脉型血管瘤最初由Hunt于1991描述(J Cutan Pathol 1991;18:235)。
It is rare, with less than 50 cases reported.
罕见，报道总数不足50例。
It presents as a slow growing, solitary, asymptomatic, purple-red papule or plaque in young to middle-aged adults, often on the trunk or limbs.
呈一种缓慢生长的、孤立的、无症状的、紫红色丘疹或斑块，见于年轻到中年成人，多位于躯干或四肢。
The histology shows a dermal proliferation of small, irregular branching capillaries and venules with inconspicuous lumina.
组织学显示真皮内小、不规则分支状毛细血管和小静脉的增生，伴不明显的血管腔隙。
Endothelial cells may be plump, but no atypia is present.
可有内皮细胞肿胀，但无不典型性。
The stroma is collagenous.
间质胶原化。
No spindle cells are present.
无梭形细胞出现。
The endothelial cells are immunoreactive for CD34 and Factor VIII related antigen.
内皮细胞呈CD34+和VIII因子相关抗原+。
Smooth muscle actin highlights pericytes surrounding the endothelial cells.
SMA染色可突出显示内皮细胞周围的外膜细胞(毛细血管)。
The main differential diagnosis is patch stage Kaposi's sarcoma, which also has irregular vascular spaces.
主要鉴别诊断是斑片期Kaposi肉瘤，它也有不规则血管腔隙。
However, they are anastomosing and not collapsed, and are accompanied by atypical endothelial cells, eosinophilic hyaline globules, plasma cells and fascicles of spindle cells.
然而，它们的血管网是吻合的，不塌陷，伴不典型内皮细胞、嗜碱性玻璃样小球、浆细胞和梭形细胞束。 
There may be irregular dissection of collagen bundles by vessels.
可有血管分割的不规则胶原束。
The spindle cells are HHV8 positive (Am J Clin Pathol 2004;121:335), and the patients are HIV positive, which is usually helpful.
梭形细胞呈HHV8+(Am J Clin Pathol 2004;121:335),且患者HIV+，有助于诊断。
However, there was a recent report of HHV8 positive microvenular hemangioma (image-see fig c, d) in an unusual case of POEMS syndrome (Arch Pathol Lab Med 2003;127:1034)
然而，也有一个最近报道了HHV8+的微静脉型血管瘤(见图c, d)，发生于一种少见的POEMS病例(Arch Pathol Lab Med 2003;127:1034)。
Kaposiform hemangioendothelioma also has slit-like lumina, although they are due to nodules and sheets of compact spindle cells.
Kaposi型血管内皮瘤也有裂隙样腔隙，尽管它们是由于致密的结节状或成片梭形细胞受挤压所致。
It affects the skin or retroperitoneum of infants and children, and may be associated with severe coagulopathy.
它累及婴儿和儿童的皮肤或后腹膜，可能与急性凝血功能紊乱有关。
Microvenular hemangioma is a benign lesion.
微静脉型血管瘤是良性病变。
To date, excision appears to be curative.
至今，肿块切除似乎可治愈。
Case reports: 40 year old woman (Dermatology 2003;206:161), 23 year old Japanese woman (Pathol Int 1998;48:237).
病例报道：40岁女性(Dermatology 2003;206:161), 23岁日本女性(Pathol Int 1998;48:237)。