Lucia Longo

Pulmonary carcinomas with pleomorphic sarcomatoid or sarcomatous elements. A clinicopathologic and immunohistochemical study of 75 cases

We collected 75 primary pulmonary carcinomas with pleomorphic, sarcomatoid, or sarcomatous elements to better define their clinical, histologic, and immunohistochemical profile. The patients age ranged from 42 to 81 years (mean 65 years), and the male-to-female ratio was 9.7:1. Sixty-nine patients (92%) were smokers. Cough and hemoptysis were the most frequent presenting symptoms. Fifty-nine patients (65%) died of disease: only stage significantly predicts overall survival (p = 0.0273). Microscopically, based on the WHO criteria, 58 cases were classified as pleomorphic carcinoma (51 with an epithelial component, 7 composed exclusively of spindle and giant cells), 10 as spindle cell carcinoma, 3 as giant cell carcinoma, 3 as carcinosarcoma, and 1 as pulmonary blastoma. Immunohistochemically, in the tumors composed exclusively of spindle and/or giant cells, thyroid transcription factor-1 (TTF-1) and cytokeratin 7 were positive in 55% and 70% of the cases, respectively, whereas surfactant protein-A was always negative. In pleomorphic carcinomas with an epithelial component, cytokeratin 7, TTF-1, and surfactant protein-A were positive in the sarcomatoid component in 62.7%, 43.1%, and 5.9% of the cases, respectively, whereas they were always negative in the sarcomatous part of carcinosarcomas and blastoma. In the epithelial component of pleomorphic carcinomas, cytokeratin 7, TTF-1, and surfactant protein-A were positive in 76.4%, 58.8%, and 39.2% of the cases, respectively, whereas the same antibodies did not react with the epithelial component of carcinosarcomas; in the case of blastoma, the epithelial part of the tumor was positive for cytokeratin 7 and TTF-1, whereas it was negative for surfactant protein-A. Cytokeratin 20 was always negative. In our opinion, this study: 1) supports the metaplastic histogenetic theory for this group of tumors; 2) shows that cytokeratin 7 and TTF-1, but not surfactant protein-A, are useful immunohistochemical markers in this setting; 3) confirms that stage is at the moment the only significant prognostic parameter, as in conventional non-small cell lung carcinomas; and 4) shows that this group of tumors has a worse prognosis than conventional non-small cell lung carcinoma at surgically curable stages I, justifying their segregation as an independent histologic type in the WHO classification.

TTF-1, Cytokeratin 7, 34βE12, and CD56/NCAM Immunostaining in the Subclassification of Large Cell Carcinomas of the Lung

We selected a 4-stain immunopanel including thyroid transcription factor (7ITF)-], cytokeratin (CK)7, 34betaE12, and CD56/neural cell adhesion molecule(NCAM) to subclassify a series of 45 pulmonary large cell carcinomas (LCCs) on bronchial biopsy. All cases consisted of a large tumor cell proliferation with abundant cytoplasm, vesicular nuclei, and prominent nucleoli. Immunohistochemically, 27 tumors (60%)were subclassified as adenocarcinoma (7TF-1 +/CK7+,24; CK7+ only, 3), 10 (22%) as squamous cell carcinoma (34betaE12+ only), and 4 (9%) as LCC with neuroendocrine differentiation (CD56+, variably stained with TTF-I and CK7, 34betaE12-). In 4 cases, the tumors coexpressed CK7 and 34betaE12 (3 cases) or were completely unstained (I case). Surgically resected tumors matched exactly with the corresponding original biopsy specimens in 21 of 23 cases; consistent CD56 expression was a reliable marker in confirming a diagnosis of large cell neuroendocrine carcinoma even on biopsy. Our results suggest that the proposed 4-stainset of commercially available markers might help subclassify LCC even in small biopsy material, validating expression-profiling studies aimed at lung cancer classification and permitting more consistent patient enrollment for trials with targeted treatments.

Primary Lung Cancer Presenting with Gastrointestinal Tract Involvement: Clinicopathologic and Immunohistochemical Features in a Series of 18 Consecutive Cases

Background: Lung cancer initially manifesting as gastrointestinal (GI)-tract metastasis is exceedingly rare, representing a diagnostic challenge and a late-stage disease sign. The clinicopathologic characteristics of the largest series of lung carcinomas initially presenting with GI involvement were described, focusing on differential diagnosis and therapeutic options. Methods: Eighteen consecutive cases of lung cancer (11 surgical specimens and 7 biopsies) initially diagnosed on GI histologic samples were identified during routine pathologist practice. All cases were immunostained with thyroid transcription factor-1 (TTF-1), caudal-related homeobox 2 (CDX2), and cytokeratins 7 (CK7) and 20 (CK20). Clinical and radiological data were obtained in all cases. Results: There were 10 women and 8 men with a mean age of 68.5 years. The small bowel was the most common GI involved site (12 cases), followed by the stomach (four) and large intestine (two). Only half of cases were correctly diagnosed on GI biopsies. Fourteen patients died shortly from disease (mean follow-up, 3 months); two are still alive with multiple metastases, and two patients with the GI tract as the unique site of metastasis underwent pulmonary lobectomy and chemotherapy and are alive without evidence of disease. At morphology, there were 10 large cell undifferentiated carcinomas and eight adenocarcinomas. All cases were immunostained for CK7 and 89% for TTF-1, whereas CK20 and CDX2 were completely negative. Conclusion: Lung cancer presenting as GI-tract metastasis is probably more frequent than expected, and pathologists should always keep in mind this possibility when dealing with undifferentiated GI carcinoma. Immunostaining with TTF-1, CDX2, CK7, and CK20 is helpful in highlighting lung primary. Although GI metastasis from lung cancer is associated with dismal outcomes, pulmonary resection coupled with chemotherapy might represent a therapeutic option in selected patients with a solitary GI-tract metastasis.

EGFR and K-ras Mutations Along the Spectrum of Pulmonary Epithelial Tumors of the Lung and Elaboration of a Combined Clinicopathologic and Molecular Scoring System to Predict Clinical Responsiveness to EGFR Inhibitors

We tested 418 neoplasms along the whole spectrum of primary lung tumor histotypes for epidermal growth factor receptor (EGFR) and K-ras mutations. Clinicopathologic data from 154 patients undergoing treatment with EGFR tyrosine kinase inhibitors (TKIs) were retrospectively studied. A scoring system assigning a score for each positive or negative characteristic (+1, female sex, nonsmoking status, adenocarcinoma histotype, Asian ethnicity, and EGFR mutation; -1, current smoker and K-ras mutation; and 0, male sex, ex-smoker, nonadenocarcinoma histotype, and no mutations) was elaborated and tested with EGFR-TKI response. Salivary gland-type, mucin-rich, and neuroendocrine tumors do not harbor EGFR mutations. A subset of nonmucinous adenocarcinomas, not necessarily of the bronchioloalveolar type, is related to EGFR mutations. Three probability groups significantly correlating with response to EGFR-TKIs were identified. Of note, the addition of molecular results did not significantly change the predictive value obtained by the combination of clinicopathologic characteristics alone in this scoring system. K-ras mutations, significantly associated with the mucin-secreting type of adenocarcinoma, consistently predict lack of response in white patients.

Kit Expression in Small Cell Carcinomas of the Lung: Effects of Chemotherapy

A significant number of small cell lung carcinomas shows overexpression of the proto-oncogene c-kit product, a tyrosine kinase known as Kit or CD117. This molecular pathway seems somewhat implicated in promoting the neoplastic growth of small cell lung carcinoma. The current pharmacological availability of its selective inhibitor, together with the promising clinical results in the management of CD117-positive neoplasms such as advanced gastrointestinal stromal tumors, aroused great interest among oncologists in also adopting this therapeutic strategy in other CD117-positive tumors. We evaluated a series of 27 small cell lung carcinomas, comparing the expression of CD117 of the primary naïve tumor (before first-line chemotherapy) with the expression of the same neoplasm after postchemotherapy relapse. All the patients underwent similar chemotherapeutic regimens (cisplatin/carboplatin plus etoposide). At diagnosis, 21 of 27 cases (78%) showed strong immunoreactivity for CD117. Among these 21 originally positive tumors, CD117 remained overexpressed in 10 after relapse (48%), whereas the other 11 cases became negative. No originally CD117-negative small cell carcinomas displayed immunoreactivity after chemotherapy. CD117 expression was not statistically correlated with overall survival, occurrence of chemoresistance, or clinical response to chemotherapy. We also evaluated CD117 expression in a series of 46 surgically resected non-small cell lung carcinomas (8 squamous cell carcinomas, 10 adenocarcinomas, 5 pleomorphic carcinomas, 10 typical and 3 atypical carcinoids, and 10 large cell neuroendocrine carcinomas). Apart from small cell carcinomas, CD117 overexpression was observed in 6 of 10 large cell neuroendocrine carcinomas, whereas all the other histotypes resulted unstained. We speculate that loss of CD117 expression after chemotherapy in a high proportion of SCLC indicates that in this tumor, Kit unlikely represents the product of a constitutive mutation, as instead shown in gastrointestinal stromal tumors. Keeping this finding in mind, oncologists could re-test CD117 expression in relapsing small cell lung carcinomas in order to establish the best candidates for enrollment in ongoing clinical trials with Kit inhibitors. Practically speaking, CD117 may be helpful in discriminating between pulmonary high-grade neuroendocrine tumors and other histotypes, but pathologists should be aware that treated small cell lung carcinomas may remain unstained in a not insignificant number of cases.

A Single Institution-Based Retrospective Study of Surgically Treated Bronchioloalveolar Adenocarcinoma of the Lung: Clinicopathologic Analysis, Molecular Features, and Possible Pitfalls in Routine Practice

Introduction: Prognostic evaluation of bronchioloalveolar carcinoma (BAC) from a homogenous population of Caucasian patients. Methods: Retrospective analysis of resected BAC reclassified according to the 2004 World Health Organization classification of lung tumors. Analyzed variables are clinicoradiologic presentation, histologic subtypes, stage, epidermal growth factor receptor (EGFR) and HER2/neu immunohistochemical expression, EGFR exons 18, 19, and 21 mutations, K-RAS exon 2 mutation. Univariate and multivariate analyses of survival were performed. Results: Of 40 patients analyzed, EGFR and HER2/neu expression were detected in 72% and 20%, respectively. HER2/neu expression significantly characterized mucinous BAC (46% versus 7%; p = 0.014). EGFR mutations were identified in 17% (30% in nonmucinous BAC and none in mucinous BAC; p = 0.083). K-RAS mutations were found in 42.5% (92% in mucinous BAC versus 18% in other types; p < 0.0001). Early stages (IA+IB) nonmucinous BAC had excellent prognosis: 5 years overall survival of 91% (100% for stage IA). Sixty six percent (4 of 6) of patients with multifocal disease died (two mucinous BAC and one nonmucinous BAC with recurrent disease). Seventy one percent (5 of 7) of patients with pneumonic-like tumor (all mucinous BAC) died of recurrent/progressive disease. Stage (p = 0.004) and histologic classifications (p = 0.035) resulted as independent prognostic factors at multivariate analysis. Conclusions: Early stage nonmucinous BAC has excellent prognosis, whereas mucinous BAC presents a poor prognosis. Locally advanced nonmucinous BAC has a poor prognosis: the diagnosis of nonmucinous BAC in large tumors should be interpreted with caution given the possible presence of invasive areas in incompletely sampled tumor. Coexpression of EGFR and HER2/neu in mucinous BAC could be considered for future trials on target therapies even in Caucasian population.

A subset of lung adenocarcinomas and atypical adenomatous hyperplasia-associated foci are genotypically related: an EGFR, HER2, and K-ras mutational analysis.

Atypical adenomatous hyperplasia (AAH) is considered the preinvasive lesion of pulmonary adenocarcinoma, and mutations of EGFR, HER2, and K-ras are involved in the early stage of lung adenocarcinoma carcinogenesis, also predicting clinical response to anti-EGFR small molecule inhibitors. We analyzed 18 cases of primary lung adenocarcinoma with concomitant AAH foci from 13 patients for mutations of EGFR (exons 18-21), HER2 (exons 19-20), and K-ras (exon 2) by direct sequencing polymerase chain reaction. Among mutated cases, concordant mutations of EGFR or K-ras in adenocarcinoma and related AAH were observed in 5 (63%) of 8 cases. In particular, 3 of 4 adenocarcinomas with EGFR mutations (all L858R point mutations in women, never or former smokers) had a concomitant and identical mutation in AAH, and 2 of 4 adenocarcinomas with K-ras mutations (both at codon 12 in women, a never and a current smoker) showed the same mutation in concomitant AAH. All cases were wild-type for HER2. Mutations of EGFR and K-ras genes represent an early event in lung adenocarcinomagenesis, and AAH convincingly seems to be a precursor lesion in a subset of cases of adenocarcinoma.

Primary high-grade mucosa-associated lymphoid tissue-type lymphoma of the cervix presenting as a common endocervical polyp

Lymphomas of the uterine cervix are uncommon neoplasms and typically appear as diffuse cervical enlargement. We describe a rare case of primary high-grade lymphoma of mucosa-associated lymphoid tissue of the uterine cervix in a 46-year-old white woman. The tumor, incidentally disclosed at gynecological examination, appeared as a single common polyp. Immunohistochemical investigation found the lesion to consist of a monomorphic CD20-positive infiltrate of large blasts and rare intermingling centrocyte-like lymphoid cells. A dense area of monotypic (lambda light-chain restriction) plasma cells was found beneath the endocervical mucosa; only a few scattered lymphoepithelial lesions were present. The neoplastic cells did not stain for CD5, CD10, CD23, CD43, or cyclin D1. A bone marrow biopsy displayed a paratrabecular, centrocyte-like B-cell infiltration, but no lymphadenopathy was detected by instrumental examination (computed tomographic scan, magnetic resonance imaging). The tumor was successfully treated by multiagent chemotherapy followed by total hysterectomy. To our knowledge, this case represents the second reported example of mucosa-associated lymphoid tissue-type lymphoma occurring in the uterine cervix. We highlight the very unusual gross appearance of this case and emphasize the difficulty of interpreting lymphoid infiltrates in the lower genital tract by microscopy.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia syndrome

The term diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) may be used to describe a clinico-pathological syndrome, as well as an incidental finding on histological examination, although there are obvious differences between these two scenarios. According to the World Health Organization, the definition of DIPNECH is purely histological. However, DIPNECH encompasses symptomatic patients with airway disease, as well as asymptomatic patients with neuroendocrine cell hyperplasia associated with multiple tumourlets/carcinoid tumours. DIPNECH is also considered a pre-neoplastic lesion in the spectrum of pulmonary neuroendocrine tumours, because it is commonly found in patients with peripheral carcinoid tumours. In this review, we summarise clinical, physiological, radiological and histological features of DIPNECH and critically discuss recently proposed diagnostic criteria. In addition, we propose that the term “DIPNECH syndrome” be used to indicate a sufficiently distinct patient subgroup characterised by respiratory symptoms, airflow obstruction, mosaic attenuation with air trapping on chest imaging and constrictive obliterative bronchiolitis, often with nodular proliferation of neuroendocrine cells with/without tumourlets/carcinoid tumours on histology. Surgical lung biopsy is the diagnostic gold standard. However, in the appropriate clinical and radiological setting, transbronchial lung biopsy may also allow a confident diagnosis of DIPNECH syndrome. DIPNECH embraces a range of conditions; we suggest the term DIPNECH syndrome to indicate a distinct patient subset http://ow.ly/YHwuK

Analysis of a panel of druggable gene mutations and of ALK and PD-L1 expression in a series of thymic epithelial tumors (TETs)

INTRODUCTION Thymic epithelial tumors (TETs) are rare neoplasms with different prognosis lacking consistent molecular alterations possibly leading to targeted therapy. We collected a consecutive series of TETs aimed at investigating the mutational status of druggable genes (EGFR, c-KIT, KRAS, BRAF, PDGFR-alpha and -beta, HER2 and c-MET) and the expression of ALK and PD-L1. PATIENTS AND METHODS One hundred twelve consecutive cases of TETs and relative clinico-pathologic features were collected. Immunohistochemical expression of ALK (clone D5F3) and PD-L1 (clone E1L3N), molecular analysis of EGFR (exons 18-21), c-KIT (exons 9,11,13,14,17), KRAS (exon 2), BRAF (exon 15), PDGFR-alpha (exon 12) and -beta (exons 12, 14, 18), HER-2 (exons 19 and 20) and c-MET (exons 14, 17, 18, 19) mutations were performed. Immuno-molecular results were then statistically matched with clinico-pathologic characteristics. RESULTS Patients were male in 54% of cases, with a median age of 61 years (range 19-83) and affected mainly by thymoma (78%) in stage II (45%). At molecular analysis, there were 4 c-KIT mutations (occurring in exon 11 V559A, L576P, Y553N and exon 17 D820E) in thymic carcinomas (typeC), but not in other tumor types (p=0.003). No mutations were detected in other genes and none case was ALK positive. Twenty-nine (26%) cases were PD-L1 positive (65% of thymic carcinomas and 18% of thymomas). High PD-L1 expression was statistically associated with WHO classification stage type C (p<0.001) and Masaoka stage III-IV disease (p=0.007). In univariate analysis, WHO classification type C, advanced Masaoka stage and absence of myasthenia, but not PD-L1 expressions were correlated with worse survival; at multivariate analysis, only WHO type C confirmed its negative prognostic role. CONCLUSION A subset of TETs as thymic carcinomas can harbor c-KIT mutations and elevated PD-L1 expression that could represent targets of potential therapeutic use.