小细胞癌

文献中共报道7例这样过诊的病例.类癌可表现为中央型或周围性病变.肿瘤细胞呈腺样,染色质颗粒状或粗糙.高水平的 chromogranin A/synaptophysin immunoreactivity,和低水平的 (<20%) Ki-67 (MIB-1) 标记指数.肿瘤间质包含薄壁血管.小细胞癌总是显示中央型定位,细而均匀分布的染色质.低度水平的chromogranin A/synaptophysin,和高水平的(>50%) Ki-67 (MIB-1) 增殖指数.间质含厚壁血管并呈球样构型.在小的挤压纤支镜活检标本中类癌过诊为小细胞癌目前仍是全球性问题.. 仔细观光HE切片及估计Ki-67 (MIB-1) 标记指数是鉴别的最有效的工具.(文献试译其主要观点).

 小心点, 没有100%的把捂, 不要发.

一个很有用的东西是KI67. 因为细胞积压太厉害, 形态上不好看.

小细胞癌是KI67>50%, 而类癌症<20%) Ki-67 . ROSAI 前几年写过一篇文章.

Am J Surg Pathol. 2005 Feb;29(2):179-87.

Typical and atypical pulmonary carcinoid tumor overdiagnosed as small-cell carcinoma on biopsy specimens: a major pitfall in the management of lung cancer patients.

Division of Pathology and Laboratory Medicine, European Institute of Oncology, University of Milan School of Medicine, Milan, Italy. giuseppe.pelosi@ieo.it

Seven patients with typical or atypical pulmonary carcinoid tumors overdiagnosed as small-cell carcinoma on bronchoscopic biopsies are described. Bronchial biopsies from 9 consecutive small-cell lung carcinoma patients were used as control group for histologic and immunohistochemical studies (cytokeratins, chromogranin A, synaptophysin, Ki-67 [MIB-1], and TTF-1). The carcinoid tumors presented as either central or peripheral lesions composed of tumor cells with granular, sometimes coarse chromatin pattern, high levels of chromogranin A/synaptophysin immunoreactivity, and low (<20%) Ki-67 (MIB-1) labeling index. The tumor stroma contained thin-walled blood vessels. Small-cell carcinomas always showed central tumor location, finely dispersed nuclear chromatin, lower levels of chromogranin A/synaptophysin, and high (>50%) Ki-67 (MIB-1) labeling index. The stroma contained thick-walled blood vessels with glomeruloid configuration. Judging from this study, overdiagnosis of carcinoid tumor as small-cell carcinoma in small crushed bronchial biopsies remains a significant potential problem in a worldwide sample of hospital settings. Careful evaluation of hematoxylin and eosin sections remains the most important tool for the differential diagnosis, with evaluation of tumor cell proliferation by Ki-67 (MIB-1) labeling index emerging from our review as the most useful ancillary technique for the distinction.

1、“我的底线是要尽量看清保存好的细胞的细微结构，（包括核染色质，核的大小，核膜情况，核丝分裂，凋亡状况，有无坏死”另外还有细胞密度（小细胞癌只所以受挤压还有是细胞的密度大），肿瘤内小血管周核酸沉积也是诊断要点之一。

2、我还有一个问题：肺活检往往取材很小啊，免疫能切那么多片吗！？

重检最好少说，做支气管镜病人非常难受的。

应当结合临床、影像学资料，再加上免疫组化作出诊断。

以上都不行，再建议外出会诊。

 支气管镜活检应该常规刷片，如果刷片见癌细胞，可以直接发；若胆小些，可以发恶性肿瘤，倾向小细胞癌，可以建议IHC确诊。

像这种小细胞癌，刷片阳性率常很高。但如果重新活检，得到的标本很可能还是损伤严重，因为小细胞癌很脆弱啊！呵呵，弱不禁风，一挤她就受不了了！