淋巴结血管肌瘤性错构瘤临床病理观察

Clinicopathological features of angiomyomatous hamartoma of lymph node

目的淋巴结血管肌瘤性错构瘤(AHL)罕见,为提高对本病的认识,对1例淋巴结血管肌瘤性错构瘤进行探讨。方法对肿瘤进行组织病理学特点观察,行免疫组化染色以及Masson三色染色和银染色,并结合文献复习讨论。结果镜下淋巴结部分结构尚存,可见少量淋巴窦和淋巴滤泡及散在灶性聚集的淋巴细胞,残存的淋巴组织多位于淋巴结被膜下或边缘区。淋巴结实质被血管、平滑肌和纤维组织取代,但无富于细胞的纤维束或平滑肌束形成。淋巴结门部有大量增生的厚壁血管,并向实质内延伸,延伸过程中血管壁由厚变薄,血管腔逐渐变小,在血管周围可见增生的平滑肌细胞围绕。部分间质纤维组织增生,伴有胶原化,可见较细的胶原纤维束,其纤维母细胞与增生的平滑肌有时不易区分。免疫组化:血管内皮细胞CD34(+),血管外周梭形细胞束SMA和desmin(+),HMB45、ER和PR(-)。Masson三色染色:胶原纤维和黏液呈蓝色,分布在胶原纤维间不成束的肌纤维呈红色。银染显示有残存的淋巴组织网状纤维。结论该病继发于淋巴结炎症性病变,淋巴结窦的血管转化和淋巴结血管肌瘤性错构瘤均由淋巴回流受阻引起,且两者具有伴发的特点。

Objective Angiomyomatous hamartoma （AMH） of lymph node （LN） is rare and not fully recognized. To improve the knowledge of this disease, we presented a case of AMH of LN and reviewed relevant literature. Methods A case of AMH of LN was studied by histopathological examination and immunohistochemical stains, including CD34, SMA, desmin, HMB-45, ER, PR, Masson and Ag. Then the case was discussed and the literature reviewed. Results The partial structures of lymph node were preserved under microscope in AMH, showing a few lymphoid sinuses and follicular centers, as well as focal lymphocyte aggregation in the subcapsular and marginal zones. The lymph node involved was partially replaced by vascular, muscular and fibrous tissues, but absence of cellular fibrous or smooth muscle fascicles. Thick-walled vessels were existed in the hilum, and gradually extended into the lymphoid tissue. During the process of extension, the vessels became thinner with smaller lument, surrounded by proliferating smooth muscles. Interstitial fibrous hyperplasia was noted with eollagenization, in which it was difficult to distinguish fibroblasts from proliferating smooth muscles. Immunohistochemical staining showed that vascular endothelial cells were positive for CD34, the spindle cells surrounding vessels were positive for SMA and desmin, but negative for HMB45, ER and PR. Masson stain showed that collagen and mucin were blue in color and muscles were red. Ag stain showed that residual reticular fibrous network was existed in the lesion. Conclusions The histological appearances supported by immunohistochemistry lead to the diagnosis of AMH of LN. Whether AMH of LN is caused by inflammation or hamartomatous change is still unclear. Impairment of lymphatic flow may be one factor related to the pathogenesis of vascular transformation of sinuses in lymph nodes and AMH of LN. Vascular transformation of sinuses in lymph nodes and AMH of LN exists in this case.