ABSTRACT
AIMS: To evaluate the clinicopathological features of small cell carcinoma arising outside the lung. METHODS AND RESULTS: Thirty-seven cases with a pathology diagnosis of extrapulmonary small cell carcinoma (EPSCC) were selected. The clinical notes were reviewed and tumour blocks were selected for a fresh haematoxylin and eosin (H&E) section and immunohistochemical stains. The most common tumour locations were cervix and bladder. Twenty-five cases (68%) were finally diagnosed as EPSCC, nine of which were found with coexisting non small cell carcinoma. Two cases (5%) were diagnosed as large cell neuroendocrine carcinoma (LCNEC) of the cervix. The remainder was classified as 10 poorly differentiated carcinomas (PDCs) (27%). Positive staining for thyroid transcription factor 1 (TTF-1) was noted in nine cases of EPSCC and in none of the cases of PDC (P = 0.034). Synaptophysin immunoreactivity was found in 20 cases of EPSCC and two cases of PDC with neuroendocrine differentiation (P = 0.002), as well as two cases of LCNEC. 34ßE12 was positive in eight cases of SCC and two cases of PDC. CONCLUSIONS: Based on this series, EPSCC may be overdiagnosed. Immunohistochemistry for TTF-1, used in combination with synaptophysin, may help to discriminate EPSCC from PDC.
Subject(s)
Biomarkers, Tumor/analysis , Carcinoma, Small Cell/diagnosis , Adolescent , Adult , Aged , Carcinoma, Small Cell/metabolism , DNA-Binding Proteins/biosynthesis , Diagnosis, Differential , Female , Humans , Immunohistochemistry , Male , Middle Aged , Synaptophysin/biosynthesis , Transcription Factors , Young AdultABSTRACT
AIMS: To assess semiquantitative immunohistochemistry as used in the diagnosis of Lynch syndrome. METHODS AND RESULTS: Tumour sections from 51 mutation carriers and 17 controls were stained with antibodies against MLH1, MSH2, MSH6 and PMS2. Intensity of immunoreactivity and percentage positivity were recorded on scales of 0-3 and 0-4, respectively. These scores were multiplied for a score of 0-12 per slide. Receiver-operator characteristic (ROC) curves of staining performance for the identification of mutation carriers were evaluated, and optimum cut-offs calculated. The area under the MLH1 ROC curve was 0.981 [95% confidence interval (CI) 0.952, 1.000]. The area under the MSH2 ROC curve was 0.899 (95% CI 0.796, 1.000). For MLH1 staining, a scoreSubject(s)
Adaptor Proteins, Signal Transducing/biosynthesis
, Adenosine Triphosphatases/biosynthesis
, Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis
, DNA Repair Enzymes/biosynthesis
, DNA-Binding Proteins/biosynthesis
, Immunohistochemistry/methods
, MutS Homolog 2 Protein/biosynthesis
, Nuclear Proteins/biosynthesis
, Adaptor Proteins, Signal Transducing/genetics
, Adenosine Triphosphatases/genetics
, Area Under Curve
, Biomarkers, Tumor/analysis
, Colorectal Neoplasms, Hereditary Nonpolyposis/genetics
, Colorectal Neoplasms, Hereditary Nonpolyposis/metabolism
, DNA Repair Enzymes/genetics
, DNA-Binding Proteins/genetics
, Female
, Heterozygote
, Humans
, Male
, Mismatch Repair Endonuclease PMS2
, MutL Protein Homolog 1
, MutS Homolog 2 Protein/genetics
, Nuclear Proteins/genetics
, ROC Curve
, Sensitivity and Specificity