Akiko Miyagi Maeshima

Grade of stromal invasion in small adenocarcinoma of the lung: histopathological minimal invasion and prognosis.

The pathologic features of invasion such as stromal disruption and pleural/vascular involvement have been shown to be of prognostic value in adenocarcinoma. However, the relationship between the degree of invasion, histologic subtype of adenocarcinoma, and prognosis remains unclear. We retrospectively studied 380 peripheral adenocarcinomas of ≤2.0 cm in diameter with regard to histology and clinical profiles. Their degree of invasive growth was classified into four grades as follows according to the structural deformity and its location in the adenocarcinoma lesion: Grade 0 had a pure bronchioloalveolar growth pattern and no evidence of stromal invasion. Grade 1 had stromal invasion in the area of bronchioloalveolar growth. Grade 2 had stromal invasion localized on the periphery of a fibrotic focus. Grade 3 had stromal invasion into the center of a fibrotic focus. The clinicopathological data were obtained from medical records. The distribution of the histologic grade of invasion was as follows: grade 0 in 85 tumors (22%), grade 1 in 37 (10%), grade 2 in 46 (12%), and grade 3 in 212 (56%). This histologic grade of invasion was closely related to other indicators of tumor spread. Vascular/lymphatic permeation was seen in none of grade 0, in 1 lesion each of grade 1 and grade 2, and 144 (68%) of grade 3. Lymph node metastasis was seen in 57 (27%) lesions of grade 3 but not in grades 0, 1, or 2. The 5-year disease-free survival rates were 100%, 100%, 100%, and 59.6% for tumors with grade 0, grade 1, grade 2, and grade 3 invasion, respectively. Tumors with grade 1 and grade 2 invasion, like tumors with grade 0 invasion (bronchioloalveolar carcinoma), showed an excellent prognosis. Therefore, tumors with grade 1 and grade 2 invasion could be considered “minimally invasive” or “early” adenocarcinomas.

Detection of EGFR Mutations in Archived Cytologic Specimens of Non–Small Cell Lung Cancer Using High-Resolution Melting Analysis

Mutations of the epidermal growth factor receptor (EGFR), particularly deletional mutations (DEL) in exon 19 and L858R in exon 21, are reportedly correlated with clinical outcome in patients with non-small cell lung cancer (NSCLC) receiving the EGFR tyrosine kinase inhibitors gefitinib and erlotinib, suggesting that detection of EGFR mutations would have an important role in clinical decision making. We established and validated an easy, inexpensive, and rapid method for detecting DEL and L858R from cytologic material by high-resolution melting analysis (HRMA). Dilution for sensitivity studies revealed that DEL and L858R were detectable in the presence of at least 10% and 0.1% EGFR-mutant cells, respectively. We analyzed 37 archived cytological slides of specimens from 29 patients with advanced NSCLC and compared the results with direct sequencing data obtained previously. Of 37 samples, 34 (92%) yielded consistent results with direct sequencing, 2 were false negative, and 1 was indeterminate. The sensitivity of this analysis was 90% (19/21) and specificity, 100% (15/15). These results suggest that HRMA of archived cytologic specimens of advanced NSCLC is useful for detecting EGFR mutations in clinical practice.

Immunohistochemical detection of GLUT-1 can discriminate between reactive mesothelium and malignant mesothelioma

The separation of benign reactive mesothelium (RM) from malignant mesothelial proliferation can be a major challenge. A number of markers have been proposed, including epithelial membrane antigen, p53 protein, and P-glycoprotein. To date, however, no immunohistochemical marker that allows unequivocal discrimination of RM from malignant pleural mesothelioma (MPM) has been available. A family of glucose transporter isoforms (GLUT), of which GLUT-1 is a member, facilitate the entry of glucose into cells. GLUT-1 is largely undetectable by immunohistochemistry in normal epithelial tissues and benign tumors, but is expressed in a variety of malignancies. Thus, the expression of GLUT-1 appears to be a potential marker of malignant transformation. Recently, in fact, some studies have shown that GLUT-1 expression is useful for distinguishing benign from malignant lesions. The purpose of the present study was to evaluate the diagnostic utility of GLUT-1 expression for diagnostic differentiation between RM and MPM. Immunohistochemical staining for GLUT-1 was performed in 40 cases of RM, 48 cases of MPM, and 58 cases of lung carcinoma. Immunohistochemical GLUT-1 expression was seen in 40 of 40 (100%) MPMs, and in all cases the expression was demonstrated by linear plasma membrane staining, sometimes with cytoplasmic staining in addition. GLUT-1 expression was also observed in 56 out of 58 (96.5%) lung carcinomas. On the other hand, no RM cases were positive for GLUT-1. GLUT-1 is a sensitive and specific immunohistochemical marker enabling differential diagnosis of RM from MPM, whereas it cannot discriminate MPM from lung carcinoma.

Utility of 10 Immunohistochemical Markers Including Novel Markers (Desmocollin-3, Glypican 3, S100A2, S100A7, and Sox-2) for Differential Diagnosis of Squamous Cell Carcinoma from Adenocarcinoma of the Lung

Introduction: Recent clinical trials revealed that accurate histologic typing of non-small cell lung cancer, especially squamous cell carcinoma (SCC), is essential. Patients and Methods: We analyzed 10 antibodies expression in 150 SCC cases (53 well-, 51 moderately, and 46 poorly differentiated cases) and 159 adenocarcinoma (AC) cases (49 well-, 52 moderately, and 58 poorly differentiated cases). Results: In all SCC and AC cases, p63 was the most sensitive marker for SCC (98.7%), followed by high-molecular-weight (HM) cytokeratin (CK) (97.3%), CK5/6 (93.3%), Sox2 (80%), thrombomodulin (79.3%), desmocollin-3 (72.7%), S100A7 (70.7%), S100A2 (63.3%), and glypican-3 (46.7%). Desmocollin-3 was the most specific marker for SCC (100%), followed by CK5/6 (98%), Sox2 (95.5%), glypican-3 (92.4%), S100A7 (86.8%), thrombomodulin (79.9%), S100A2 (64.6%), p63 (51.6%), and HMCK (33.3%). Thyroid transcription factor-1 (TTF-1) expression was observed in 87.4% of AC cases and 2.0% of SCC cases. When analyzing only poorly differentiated tumors, HMCK was the most sensitive marker for SCC (100%), followed by p63 (97.8%), CK5/6 (87.0%), Sox2 (71.7%), thrombomodulin (58.7%), desmocollin-3 (52.2%), S100A2 (50%), glypican-3 (45.7%), and S100A7 (45.7%). Desmocollin-3 was the most specific marker for poorly differentiated SCC (100%), followed by CK5/6 (98.3%), glypican-3 (94.8%), Sox2 (94.8%), S100A2 (81%), S100A7 (75.9%), thrombomodulin (72.4%), p63 (48.3%), and HMCK (36.8%). The 10-fold crossvalidated classification and regression tree analysis revealed that the combination of CK5/6 and TTF-1 was the best immunohistochemical marker panel for the differentiation between SCC and AC. Conclusion: CK5/6 is the best marker for differentiating SCC and AC, irrespective of the histological grade of the tumor. Thus, the combination of CK5/6 and TTF-1 is the most recommended combination of immunohistochemical markers.

Epidermal growth factor receptor mutation status and clinicopathological features of combined small cell carcinoma with adenocarcinoma of the lung

In lung cancer, somatic mutations of epidermal growth factor receptor (EGFR) are concentrated in exons 18–21, especially in adenocarcinoma (Ad), but these mutations have rarely been reported in small cell lung carcinoma (SCLC). Combined SCLC is rare, and the EGFR mutation status and its relationship to the clinicopathological features of this tumor type have not yet been elucidated. We retrospectively studied six patients with combined SCLC with Ad components among 64 consecutive patients who underwent resection of SCLC. The clinicopathological features of each patient were reviewed, especially for the distribution pattern of the Ad component and lymph node metastases. EGFR mutations were screened by high‐resolution melting analysis in each case, and were confirmed by sequencing of each mutation in the microdissected SCLC or Ad components. Regarding EGFR, no specific mutation was detected in five of the six patients, whereas one female patient who had never smoked had a missense mutation. In this case, both the SCLC and Ad components shared the same mutation in exon 21 (L858R). We identified a patient with combined SCLC with Ad sharing an identical EGFR mutation in both the SCLC and Ad components. In addition to the clinicopathological characteristics of this rare histological type of lung cancer, these findings provide useful information for better understanding the biology, natural history and clinical management of SCLC. (Cancer Sci 2007; 98: 1714–1719)

CD5-positive diffuse large B-cell lymphoma: a retrospective study in 337 patients treated by chemotherapy with or without rituximab

BACKGROUND CD5-positive (CD5+) diffuse large B-cell lymphoma (DLBCL) shows poor prognosis and frequent central nervous system (CNS) relapses under anthracycline-containing chemotherapy. The aim of this study was to determine the prognosis and CNS relapse incidence of CD5+ DLBCL in the rituximab era. PATIENTS AND METHODS We analyzed 337 patients with CD5+ DLBCL who received chemotherapy with (R-chemotherapy group; n = 184) or without (chemotherapy group; n = 153) rituximab. RESULTS No significant difference was found in clinical background comparisons between the two groups. In the R-chemotherapy group, 60% of the patients were older than 65 years at diagnosis. Both the complete response rate and overall survival (OS) were significantly better in the R-chemotherapy group (P = 0.0003 and P = 0.002, respectively). Multivariate analysis confirmed that chemotherapy without rituximab was associated with unfavorable OS. However, the probability of CNS relapse did not differ between the two groups (P = 0.89). The CNS relapse was strongly associated with short OS (P < 0.0001). In the R-chemotherapy group, 83% of patients who experienced CNS relapse had parenchymal disease. CONCLUSIONS Our results indicate that rituximab improves the OS of patients with CD5+ DLBCL but does not decrease the CNS relapse rate. More effective treatments with CNS prophylaxis are needed for CD5+ DLBCL patients.

SOX10 is a novel marker of acinus and intercalated duct differentiation in salivary gland tumors: a clue to the histogenesis for tumor diagnosis.

Salivary gland tumors are relatively rare and morphologically diverse and heterogeneous tumors; therefore, histogenesis-based tumor markers are sorely needed to aid in diagnosing and determining the cell type of origin. SRY-related HMG-box 10 (SOX10) protein is a transcription factor known to be crucial in the specification of the neural crest and maintenance of Schwann cells and melanocytes. In addition, positive expression has also been implicated in the major salivary gland. Here, we examined SOX10 expression in various salivary gland tumors to correlate this expression with myoepithelial markers. Overall, 76 malignant and 14 benign tumors were examined. SOX10 expression clearly delineated two distinct subtypes of human salivary gland tumors; acinic cell carcinomas, adenoid cystic carcinomas, epithelial-myoepithelial carcinomas, myoepithelial carcinomas, and pleomorphic adenomas, including the pleomorphic adenoma component of carcinoma, were SOX10 positive, while salivary duct carcinomas, mucoepidermoid carcinomas, an oncocytic carcinoma, Oncocytomas, and Warthin tumors were SOX10 negative. Also, SOX10 was expressed in solid-type or non-specific morphology salivary gland tumors, but was not expressed in poorly differentiated squamous cell carcinomas. In normal human salivary gland tissue, SOX10 expression was specific to the nuclei of acini and both luminal and abluminal cells of intercalated ducts but not in other sites. Moreover, the murine model suggested that SOX10 continued to be expressed from the developmental stage to adulthood in the acinar and both luminal and abluminal intercalated ducts in the major salivary gland. Thus, SOX10 is a novel marker for diagnosing and understanding the histogenesis of salivary gland tumors.

Frequent MED12 mutations in phyllodes tumours of the breast

Background:Phyllodes tumours are rare fibroepithelial tumours of the breast, that include benign, borderline, and malignant lesions. Although the molecular basis of phyllodes tumours largely remains unknown, a recent exome study identified MED12 mutations as a sole recurrent genetic alteration in fibroadenoma, a common benign fibroepithelial tumour that shares some histological features with the phyllodes tumour.Methods:Forty-six phyllodes tumours and 58 fibroadenomas of the breast were analysed for MED12 mutations by using Sanger sequencing.Results:MED12 mutations were identified in 37 out of the 46 phyllodes tumours (80%). The prevalence of MED12 mutations was similar among benign (15/18, 83%), borderline (12/15, 80%), and malignant tumours (10/13, 77%). MED12 mutations were also identified in 36 of the 58 fibroadenomas (62%). The mutations were frequent among intracanalicular-type (24/32, 75%) and complex-type lesions (4/6, 67%), but were significantly less common among the pericanalicular-type lesions (8/20, 40%). A microdissection-based analysis showed that MED12 mutations were confined to the stromal components in both phyllodes tumours and fibroadenomas.Conclusions:MED12 mutations were frequent among the phyllodes tumours of the breast, regardless of the tumour grade. Phyllodes tumours and fibroadenomas share, at least in part, a common genetic background.

Histological Scoring for Small Lung Adenocarcinomas 2 cm or Less in Diameter: A Reliable Prognostic Indicator

Objective: Lung adenocarcinomas 2 cm or less in diameter were studied to develop histologic criteria predicting the outcome. Materials and Methods: We reviewed 510 consecutive lung adenocarcinomas 2 cm or less in diameter and assessed three histologic parameters to implement a histologic scoring system: lymphovascular invasion, maximum diameter of the nonbronchioloalveolar carcinoma (BAC) component, and percentage of the solid, cribriform, and/or papillary component in the entire tumor volume (%solid/cribriform/papillary). One point was given to each of lymphovascular invasion-positive, non-BAC >10 mm and %solid/cribriform/papillary ≧30%, and by the sum of these points, a score of 0 to 3 was assigned for each tumor. We also evaluated minimally invasive adenocarcinomas comprising non-BAC ≦5 mm, Sakurai grades 1 and 2. Results: Five-year disease-free survival rates of 287 patients with a histologic score of 0, 69 with a score of 1, 64 with a score of 2, and 90 with a score of 3 were 98.9%, 92.4%, 78.4%, and 54.0%, respectively. The 510 tumors included 129 noninvasive and 127 minimally invasive adenocarcinomas. None of these tumors recurred. In remaining 254 patients with overtly invasive adenocarcinomas, 5-year disease-free survival rates in 51 with a histologic score of 0, 49 with a score of 1, 64 with a score of 2, and 90 with a score of 3 were 95.9%, 89.2%, 79.4%, and 54.2%, respectively. Conclusion: The histologic scoring system comprising lymphovascular invasion-positive, non-BAC >10 mm and %solid/cribriform/papillary ≧30% is able to predict the outcome of lung adenocarcinomas 2 cm or less in diameter not only in all cases but also in overtly invasive adenocarcinomas. Minimally invasive adenocarcinomas did not recur in this large series.

Analysis of expression patterns of breast cancer-specific markers (mammaglobin and gross cystic disease fluid protein 15) in lung and pleural tumors.

CONTEXT The lung is the most common site of metastasis during the natural history of malignant tumors. Breast carcinoma has a propensity for distant metastasis, and the lung and pleura are among the most common metastatic sites. Although it is often difficult to make a clear-cut differential diagnosis between the two, distinguishing primary lung carcinoma from breast carcinoma metastatic to the lung is important because the treatment modalities are different. OBJECTIVE To elucidate the utility of mammaglobin and gross cystic disease fluid protein 15 (GCDFP-15), which are known to be breast-specific antigens, in distinguishing various primary lung and pleural tumors from breast carcinoma metastasizing to the lung. DESIGN A total of 20 cases of breast carcinoma metastatic to the lung and 263 tumors of nonbreast origin located in the lung and pleura were analyzed. RESULTS Of the 20 cases of breast carcinoma metastatic to the lung, 10 (50.0%) were immunoreactive for mammaglobin and 9 (45.0%) for GCDFP-15, the frequency of positivity being slightly higher for the former than for the latter. The area immunopositive for mammaglobin showed more diffuse staining than the area immunopositive for GCDFP-15. Furthermore, the specificity of mammaglobin for breast carcinoma metastatic to the lung was superior (98.9%) to that of GCDFP-15 (91.8%). CONCLUSION The sensitivity of mammaglobin is equal or superior to that of GCDFP-15 for investigation of breast carcinoma. Immunopositivity for mammaglobin is more diffuse than that for GCDFP-15. In terms of practical diagnosis, mammaglobin immunohistochemistry can serve as a differential marker of breast carcinoma and should be added to the immunohistochemical panel.