浆细胞肿瘤病理形态的多样性

Morphologic diversity of plasma cell neoplasms

目的 观察浆细胞肿瘤的病理形态学特点,探讨其组织结构和细胞形态的类型及其鉴别诊断.方法应用HE、免疫组织化学（EliVision法）,对46例浆细胞肿瘤的组织形态学及免疫表型进行研究.结果 46例浆细胞肿瘤中,有40例组织结构以弥漫分布为主,3例呈巢状结构而似神经内分泌肿瘤,3例出现硬化的纤维性背景.淀粉样物质沉积、钙化骨化及＂血湖＂样结构在部分病例中有可能会非常突出而掩盖了肿瘤性浆细胞的特点.细胞形态上,30例由较成熟和欠成熟的浆样细胞组成而较易辨认.6例由类似免疫母细胞的浆母细胞组成.4例肿瘤细胞较小,似小淋巴细胞.2例瘤细胞胞质透亮似透明细胞或印戒细胞.另各有1例分别由异型性明显的间变型细胞、组织细胞样细胞及梭形细胞构成.最后1例细胞形态多样,可出现分叶核、单核及多核型细胞.免疫表型上93.1%（27/29）的病例表达CD79a而仅有5.1%（2/39）的病例表达CD20,87.1%（27/31）的病例表达CD38和83.3%（25/30）表达CD138,96.8%（30/31）的病例表达MUM-1.38例呈免疫球蛋白轻链限制性表达,其中表达λ链27例,表达κ链11例.结论浆细胞肿瘤除了常见的组织形态外,还可出现不典型或少见的组织结构和细胞形态,诊断时应注意与其他类型淋巴瘤如小淋巴细胞淋巴瘤及间变性大细胞淋巴瘤、低分化癌、透明细胞或印戒细胞癌、间叶性肉瘤等进行鉴别,免疫组织化学是必不可少的.

Objective To investigate the architectural and cytological variations of plasma cellneoplasms, and discuss the diagnosis and differential diagnosis. Methods Histological and immunohistochemical examinations were used to study the morphologic and immunophenotypic features of 46cases of plasma cell neoplasms. Results 40 out of 46 cases were diffuse growth pattern. 3 cases had a nestlike architecture that can mimic neuroendocrine tumors and 3 cases had a prominent fibrous sclerosis background. Amyloid deposition, calcification or ossification and angiomatoid areas can be prominent and may obscure the neoplastic plasma cells. Cytologically, 30 cases were composed of relatively mature plasma cells and can be recognized without too much difficulty. Tumor cells resembled immunoblasts in 6 cases and small lymphocytes in 4 cases. In another 2 cases tumor cells were easily confused with Signet-ring cells or clear cells. Tumor cells were composed of anaplastic cells, histocytoid cells and spindle cells in each one case, respectively. Lastly, tumor cells can be polymorphous which composed of multilobated, monocytoid or multinucleated cells in one case. 93. 1% （27/29） cases expressed CD79a while only 5. 1% （2/39） cases expressed CD20. 87.1% （27/31） cases expressed CD38 and 83.3% （25/30） cases expressed CD138,96. 8% （30/31） cases expressed MUM-1. Light chain restrictions were detected in 38 cases, that 27 cases expressed lambda and 11 for kappa. Conclusions Except for the common architecture and cytology in plasma cell tumor, unusual morphology may appear. Thus, pay attention to distinguish from lymphoma such as small lymphocytic lymphoma and anaplastic large cell lymphoma, pooly differentiated carcinoma, clear cell carcinoma or Signet-ring cell carcinoma, sarcoma, etc. And immunohistochemistry is essential in the diagonosis.