ABSTRACT
OBJECTIVE: To determine whether the presence of vimentin and leukocyte common antigen (LCA)-negative molding cells (VLNMC) could help in identifying rare small cell lung carcinoma (SCLC) cells. STUDY DESIGN: Thirty-four cell blocks of pleural effusions (PEs) from 26 patients with confirmed SCLC were stained immunohistochemically with vimentin and LCA antibodies and compared with hematoxylin and eosin-stained preparations. RESULTS: VLNMC were present in 22/22 PEs originally diagnosed as positive or atypical/suspicious for SCLC. Focal vimentin staining was seen in SCLC in 10/22 cases, and 1 case showed many vimentin-positive SCLC cells. One of 11 PEs originally interpreted as negative showed rare groups of VLNMC. This was supported by a subsequent PE obviously positive for SCLC. CONCLUSION: Immunoperoxidase stains for vimentin and LCA highlight SCLC in PEs as VLNMC; however, morphologic criteria must prevail in making the final diagnosis.
Subject(s)
Biomarkers, Tumor/analysis , Carcinoma, Small Cell/pathology , Leukocyte Common Antigens/analysis , Lung Neoplasms/pathology , Pleural Effusion, Malignant/pathology , Vimentin/analysis , Antibodies , Carcinoma, Small Cell/metabolism , Eosine Yellowish-(YS) , Hematoxylin , Humans , Immunoenzyme Techniques , Lung Neoplasms/metabolism , Pathology, Clinical/methods , Pleural Effusion, Malignant/metabolism , Predictive Value of Tests , Reproducibility of ResultsABSTRACT
Correlation of loss of heterozygosity (LOH) of p53, BRCA1, VHL, and estrogen receptor (ER) genes with the expression of related protein products and morphologic features predictive of aggressive biologic behavior was investigated to determine the significance of LOH in these genes. DNA from 35 formalin-fixed, paraffin-embedded breast carcinomas was obtained by microdissection of histologic sections. LOH was determined by polymerase chain reaction (PCR) using primers TP53, D3S1038, D17S855, and ESR for p53, VHL, BRCA1, and ER genes, respectively. p53, ER, and progesterone receptor (PR) protein expression was evaluated by immunohistochemistry. Morphologic evaluation included histologic type, and histologic and nuclear grades. TP53 LOH was identified in 13 (52%), BRCA1 LOH in 3 (17%), VHL LOH in 1 (4%), and ER LOH in 4 (21%) of 25, 17, 24, and 19 informative cases, respectively. p53 and ER protein expression was identified in 20 (57%) and 25 (71%) cases, respectively. TP53 LOH directly correlated with both high histologic and nuclear grade (P<0.01). BRCA1, VHL, and ER LOH was not frequent enough for correlation to morphologic features. Although 4 of 4 ER and 7 of 13 p53 LOH cases expressed related proteins, LOH did not correlate with protein expression. TP53 LOH may be an event contributing to aggressive biologic behavior since it is strongly associated with high histologic and nuclear grade. Missense or nonsense mutations may explain the absence of detectable p53 protein in 6 of 13 cases with p53 LOH. All 4 ER LOH cases expressed ER protein. BRCA1 and VHL LOH is infrequent in sporadic breast carcinoma.
