Histomolecular profiling of pleomorphic, spindle cell, and giant cell carcinoma of the lung for targeted therapies

Inflammatory Giant Cell Carcinoma of the Lung: Clinicopathologic, Immunohistochemical, and Next-generation Sequencing Study of 14 Cases

A distinctive histological variant of poorly differentiated, sarcomatoid, non-small cell lung carcinoma characterized by a discohesive population of giant tumor cells associated with prominent interstitial inflammatory cell infiltrates is described. The tumors occurred in 7 women and 7 men, 42 to 72 years of age (mean: 56 y). They predominantly affected the upper lobes and measured 1.3 to 9 cm in greatest diameter (mean: 4.6 cm). The tumor cells were characterized by large pleomorphic nuclei with prominent nucleoli, ample cytoplasm, and frequent abnormal mitoses, and were surrounded by a dense inflammatory cell infiltrate, often associated with emperipolesis. Immunohistochemical stains were positive in the tumor cells for cytokeratin AE1/AE3 and CK8/18 and negative for TTF1, napsin A, p40, and CK5/6. Next-generation sequencing was performed in all cases using the Oncomine Precision Assay; the most common abnormalities found included TP53 mutations (9 cases) and AKT1 amplification (8 cases), followed by KRAS mutations (4 cases) and MAP2K1/2 mutations (4 cases). Clinical follow-up was available in 13 patients. Three patients presented with metastases as the initial manifestation of disease; 8 patients died of their tumors from 6 months to 8 years (mean: 2.7 y); 3 patients were alive and well from 4 to 6 years; and 2 patients had metastases when last seen but were lost to follow-up thereafter. The importance of recognizing this distinctive and aggressive variant of non-small cell lung carcinoma lies in avoiding confusion with a sarcoma or other types of malignancy.

An observational study on the efficacy of targeted therapy for pulmonary sarcomatoid carcinoma

BACKGROUND

Pulmonary sarcomatoid carcinoma is a rare tumor that is resistant to cytotoxic agents. This observational study aimed to evaluate the detection rate of driver gene alteration and the efficacy of targeted therapy for pulmonary sarcomatoid carcinoma.

METHODS

We established a database of patients with pulmonary sarcomatoid carcinoma and their clinical information, including EGFR mutation, ALK fusion gene, ROS1 fusion gene, BRAF mutation, and MET exon 14 skipping mutation. The present study retrieved and analyzed the data of patients with pulmonary sarcomatoid carcinoma in whom driver gene alterations were evaluated, and the survival duration after the initiation of treatment with targeted therapy was examined.

RESULTS

A total of 44 patients were included in the present study. The EGFR mutation, ALK fusion gene, and MET exon 14 skipping mutation were detected in 2/43 patients (4.7%), 2/34 patients (5.9%), and 2/16 patients (12.5%), respectively. The ROS1 fusion gene (0/18 patients) and BRAF mutation (0/15 patients) were not detected. Female patients (P = 0.063, Fisher's exact test) and patients without smoking history (P = 0.025, Fisher's exact test) were the dominant groups in which any driver mutation was detected. Five patients with driver gene alterations were treated with targeted therapy. Progression-free survival (PFS) was 1.3 months and 1.6 months in 2 of the patients treated with gefitinib. Two patients with the ALK fusion gene showed 2.1 and 14.0 months of PFS from the initiation of treatment with crizotinib, and a patient with the MET exon 14 skipping mutation showed 9.7 months of PFS from the initiation of treatment with tepotinib.

CONCLUSION

The EGFR mutation, ALK fusion gene, and MET exon 14 skipping mutation were detected in patients with pulmonary sarcomatoid carcinoma in clinical practice, and some patients achieved long survival times after receiving targeted therapy. Further investigation is necessary to evaluate the efficacy of targeted therapy for pulmonary sarcomatoid carcinoma.

Primary Pulmonary Carcinomas with Spindle and/or Giant Cell Features: A Review with Emphasis in Classification and Pitfalls in Diagnosis

Primary carcinomas of the lung are vastly represented by the conventional types of adenocarcinomas or squamous cell carcinomas. However, there are other types of non-small cell carcinomas that although uncommon represent a meaningful group that often pose a problem not only in diagnosis but also in classification. Spindle cell and/or giant cell carcinomas, although uncommon represent an important group of primary lung carcinomas. Important to highlight is that current criteria are rather ambiguous and likely not up to date, which renders the classification of these tumors somewhat more obscure. In addition, with the daily use of immunohistochemical stains, the classification of these tumors may also pose a different problem in the proper allocation of these tumors. Proper classification is highly important in the selection process that takes place using such material for molecular analysis. The current molecular characteristics of these tumors are limited and lack more in-depth studies and analyses that can provide specific targets for the treatment of patients with these tumors. The current review attempts to highlight the shortcomings in the current classification and definitions of these neoplasms as well as the more current view regarding these tumors when the use of immunohistochemical stains is employed.

Clinicopathological features and prognostic nomogram of giant cell carcinoma of the lung: A population-based study

BACKGROUND

Due to its rarity, the features and prognosis of giant cell carcinoma of the lung (GCCL) are not well defined. The present study aimed to describe the clinicopathological features and prognostic analysis of this rare disease, compare it with lung adenocarcinoma (LAC), further determine the prognostic factors and establish a nomogram.

METHODS

Patients diagnosed with GCCL and LAC were identified from the SEER database between 2004 and 2016. The features and survival between GCCL and LAC were compared in the unmatched and matched cohorts after propensity score matching (PSM) analysis. Univariate and multivariate Cox analyses were used to identify the prognostic factors, and a nomogram was constructed. Area under the curve (AUC), C-index, calibration curve and decision curve analysis (DCA) were used to confirm the established nomogram.

RESULTS

A total of 295 patient diagnosed with GCCL and 149 082 patients with LAC were identified. Compared with LAC, patients with GCCL tend to be younger, male, black and have pathological Grade III/IV GCCL, more proportion of AJCC-TNM-IV, T3/T4 and distant metastases. The 1-, 2- and 5-year OS rates of the patients with GCCL were 21.7%, 13.4% and 7.9%, respectively. The median OS and CSS were 3 and 4 months, respectively. Patients with GCCL had significantly shorter OS and CSS than those with LAC in the unmatched and matched cohorts after PSM. Multivariate Cox analysis demonstrated that T, N and M stages and use of chemotherapy and surgery were independent of survival. Furthermore, we constructed a prognostic nomogram for OS and CSS by using independent prognostic factors. The C-index of OS-specific nomogram is 0.78 (0.74-0.81), and the C-index of CSS-specific nomogram is 0.77 (0.73-0.80). The calibration curve and ROC analysis showed good predictive capability of these nomograms. DCA showed that the nomogram had greater clinical practical value in predicting the OS and CSS of GCCL than TNM staging.

CONCLUSION

GCCL have distinct clinicopathological characteristics and significantly worse clinical outcomes. Prognostic nomograms for overall survival (OS) and CSS were constructed.

The Correlation Between Histologic, Immunophenotypic, and Molecular Characteristics of Pulmonary Sarcomatoid Carcinoma Reveals That Sarcomatoid Change Is Potentially Derived From Epithelial Carcinoma Cells Undergoing Epithelial-Mesenchymal Transition

Pulmonary sarcomatoid carcinoma (PSC) is characterized by biphasic tumors with epithelial and mesenchymal phenotype. Little is known about the correlation between histologic, immunophenotypic features and the genetic profile of PSC. We analyzed the expression of epithelial-mesenchymal transition-related markers, adenocarcinoma (ADC) and squamous cell carcinoma lineage-specific markers of 205 PSC cases. The alteration of 5 targeted genes was detected by amplification-refractory mutation system-polymerase chain reaction. The intensity of cytokeratin staining was stronger in epithelial carcinoma (EC) than that of the sarcomatoid component (SC) of pleomorphic carcinoma, while vimentin was positive in only 16.3% (17/104) of EC of pleomorphic carcinoma. There is no significant difference between thyroid transcription factor 1 (TTF-1) expression in the SC (46.5%, 33/71) of pleomorphic carcinoma with ADC components and pure PSC (44.2%, 42/95) without p40 expression ( P =0.858). Four cases with ALK rearrangement were confirmed to co-express ALK fusion protein in both the SC and EC. The incidence of EGFR/ALK/KRAS mutation was similar between pleomorphic carcinoma with ADC components (40.6%, 26/64) and TTF-1 + pure PSC (38.2%, 13/34) ( P =0.583). However, higher proportions of TTF-1 + /p40 - PSC patients (44.8%, 39/87) had EGFR/ALK/KRAS mutation than those with TTF-1 - /p40 - PSC (16.7%, 4/24) ( P =0.031). The incidence of EGFR mutation was significantly higher in TTF-1-positive (18.4%, 16/87) than TTF-1-negative (2.7%, 2/74) PSC ( P =0.002). No EGFR and ALK abnormality were observed in 24 pleomorphic carcinoma cases with squamous cell carcinoma components or pure PSC with p40 expression. Our study reveals a close correlation between SC and EC components of pleomorphic carcinoma in terms of immunophenotypic and genetic features, which suggests that pleomorphic carcinoma is potentially derived from the sarcomatoid change of EC cells undergoing epithelial-mesenchymal transition.

Anti-CK7/CK20 Immunohistochemistry Did Not Associate with the Metastatic Site in TTF-1-Negative Lung Cancer

Anti-CK7 and anti-CK20 immunohistochemistry is sometimes used to establish a diagnosis of primary lung cancer. We performed a retrospective study on the value of anti-CK7 and anti-CK20 immunohistochemistry in 359 biopsies of patients with suspected lung carcinoma in order to assess the usefulness of these antibodies in the evaluation of lung tumors in biopsies. Our results showed TTF-1 positivity in 73.3% of patients. EGFR mutations and ALK rearrangements were significantly different between TTF-1 positive and TTF-1 negative tumors (p < 0.001 and p = 0.023, respectively). Our results show a significant difference (p < 0.001) between TTF-1 positive and TTF-1 negative carcinomas with a median survival of 21.97 months (CI95% = 17.48−30.9 months) and 6.52 months (CI95% = 3.34−10.3 months), respectively. In the group of TTF-1 negative patients, anti-CK7 and CK20 immunohistochemistry was performed in 70 patients and showed CK7+/CK20- staining in 61 patients (87.1%), CK7-/CK20- in 4 patients (5.7%), CK7+/CK20+ in 3 patients (4.3%), and CK7-/CK20- in 2 patients (2.8%). No specific or molecular pattern was found in these groups of CK7/CK20 combinations. In total, this work brings arguments concerning the uselessness of anti-CK7/CK20 immunohistochemistry in the case of suspicion of primary lung cancer in biopsies.

PSC subtyping based on TTF-1 and p40 expression reveals distinct molecular characteristics and therapeutic strategies

Pulmonary sarcomatoid carcinoma (PSC) is a unique form of poorly differentiated non-small cell lung cancer (NSCLC) and is notorious for its highly malignant nature and dismal prognosis. To introduce effective treatment for PSC patients, precise subtyping of PSC is demanding. In our study, TTF-1 and P40 immunohistochemistry (IHC) staining were applied to 56 PSC patients with multi-omics data. According to IHC results, we categorized these patients into three subgroups and profiled their molecular contexture using bioinformatic skills. IHC results classified these patients into three subgroups: TTF-1 positive subgroup (n=27), P40 positive subgroup (n=15), and double-negative subgroup (n=14). Spindle cell samples accounted for 35.71% (5/14) of double-negative patients, higher than others (p=0.034). The three subgroups were heterogeneous in the genomic alteration spectrum, showing significant differences in the RTK/RAS pathway (p=0.004) and the cell cycle pathway (p=0.030). The methylation profile of the double-negative subgroup was between the other two subgroups. In similarity analysis, the TTF-1 and p40 subgroups were closely related to LUAD and LUSC, respectively. The TTF-1 positive subgroup had the highest leukocyte fraction (LF) among several cancer types, and the tumor mutation burden (TMB) of the p40 positive subgroup ranked third in the TMB list, suggesting the applicability of immunotherapy for PSC. The study established a new subtyping method of PSC based on IHC results and reveals 3 subgroups with distinct molecular features, providing evidence for refined stratification in the treatment of PSC. This article is protected by copyright. All rights reserved.

WHO grading system for invasive pulmonary lung adenocarcinoma reveals distinct molecular signature: An analysis from the cancer genome atlas database

Lung adenocarcinoma grading has gained interest in the past years. Recently a three-tier tumor grading was proposed showing that it is related to patients' prognosis. Nevertheless, the underlying molecular basis of this morphological grading remains partly unknown. The aim of our work is to take advantage of The Cancer Genome Atlas lung adenocarcinoma (TCGA_LUAD) cohort to describe the molecular data associated to tumor grading. We performed a study on publicly available data of the TCGA database first by assessing a tumor grade on downloadable tumor slides. Secondly we analyzed the molecular features of each tumor grade group. Our work was performed on a study group of 449 patients. We show that aneuploidy score was significantly different between grade 2 and grade 3 groups with different chromosomal imbalance (p < 0.001). SCGB1A1 mRNA expression was higher in grade 2 (p = 0.0179) whereas NUP155, CHFR, POLQ and CDC7 have a higher expression in grade 3 (p = 0.0189, 0.0427, 0.0427 and 0.427 respectively). GZMB and KRT80 have a higher methylation of DNA in grade 2 (p = 0.0201 and 0.0359 respectively). MT1G, CLEC12B and NDUFA7 have a higher methylation of DNA in grade 3 (p < 0.001, 0.0246 and 0.0359 respectively). We showed that the number of activated pathways is different between grade 2 and grade 3 patients (p = 0.004). We showed that differentially expressed genes by mRNA analysis and DNA methylation analysis involve several genes implied in chemoresistance. This could suggest that grade 3 lung adenocarcinoma might be more resistant to chemotherapy.

Clinicopathological and Prognostic Features of 67 Cases with Pulmonary Sarcomatoid Carcinoma: An 18-Year Single-Centre Experience

INTRODUCTION

Pulmonary sarcomatoid carcinoma (PSC) is a very rare subtype of non-small-cell lung cancer (NSCLC). It is frequently diagnosed in the advanced stage and is resistant to conventional chemotherapeutics. Due to the unique nature and rarity, we evaluated the epidemiological, clinicopathological, and survival data of PSC patients treated at our centre.

PATIENTS AND METHODS

We retrospectively collected demographic and clinical data of 67 PSC patients from a single tertiary referral hospital, between the 2000 and 2018. Univariate and multivariate analyses were performed to determine the risk factors affecting survival.

RESULTS

The median age was 61 years, and the percentage of male was 74.6%. Most of the patients had a smoking history (76.9%). The most common PSC subtype was pleomorphic carcinoma (46.3%). The median overall survival (OS) was 55.4 months, and the 5-year OS rate was 47.5%. Advanced stage, T4 tumour, and positive lymph node involvement were associated with poor OS (p < 0.05). The patients with negative epithelial markers had poorer prognosis (p = 0.027) and had more frequently stage IV disease (p = 0.016). Surgical treatment and stage IV disease were determined to be independent prognostic factors.

CONCLUSION

PSC is an extremely rare and aggressive variant of NSCLC. Positive epithelial markers may have favourable prognostic significance in PSC. Resection of the tumour with a negative surgical margin is crucial for better survival. The prognosis of the disease is very poor in the metastatic stage.

Brain metastasis PD-L1 and CD8 expression is dependent on primary tumor type and its PD-L1 and CD8 status

Background

Brain metastases (Bmets) are frequent; however, limited data exist on the efficacy of immunotherapy in these lesions. The aims of the study were to analyze the immunohistochemical expressions of programmed death ligand 1 (PD-L1) and CD8 in Bmets and to compare them with their expressions in paired primary tumors, as well as correlate the results with clinicopathological features.

Methods

This is a retrospective study of 233 patients with Bmets and 111 paired primaries. Clinical, histological, and molecular data were recorded and compared with the immunohistochemical results of PD-L1 and CD8 expressions. The statistical analysis included χ² test, Cramer’s V test, factorial analyses of variance, simple regression analysis, and Kaplan-Meier analysis with log-rank product limit estimation.

Results

PD-L1 expression was found in 23.6% of Bmets and in 29.0% of primary tumors with concordant expression between them in 75.5% of cases. Bmets PD-L1 expression was associated with primary tumor PD-L1 expression and the primary tumor type. Significant CD8 peritumoral expression was found in 68.6% of Bmets and in 87.7% of primary tumors. CD8 expression was concordant between primary and metastatic tumors in 73.3% of cases. Bmets CD8 expression was associated with primary tumor CD8 expression and primary tumor type. PD-L1 expression was associated with CD8 expression in both primary and metastatic tumors. The concordance between primary and metastatic tumor PD-L1 expression was independent of all factors studied. The concordance between primary and metastatic CD8 expressions was marginally associated to the time of Bmets development. No prognostic role for PD-L1 and CD8 expression in Bmets was found.

Conclusion

PD-L1 and CD8 Bmets expressions are associated with the primary tumor type and its PD-L1 and CD8 expressions. No factor predicts the discordance for PD-L1 expression, while time to Bmets development is associated with CD8 expression discordance.

Pulmonary sarcomatoid carcinoma: progress, treatment and expectations

Pulmonary sarcomatoid carcinoma (PSC) is a unique, highly invasive pulmonary malignancy with a poor prognosis, representing 0.1-0.4% of all malignant lung tumors. Because of its highly aggressive character and propensity for frequent metastasis, PSC shows low response rates to traditional treatments such as chemotherapy, radiotherapy, and neoadjuvant therapy. In recent years, considerable progress has been made in gene sequencing, targeted therapies, and immunotherapies. One of the most promising treatment approaches is the selection of mono-targeted or multi-targeted drugs according to tumor gene-mutation sites, such as epidermal growth factor receptor or vascular endothelial growth factor receptor 2 (EGFR/VEGFR2), anaplastic lymphoma kinase (ALK), and others. Another approach is the activation of therapeutic anti-tumor immunity via pathways including programmed cell-death protein-1/programmed cell-death ligand-1 (PD-1/PD-L1), which has been used in individual cases. In this review, we will introduce the clinicopathologic features, molecular typing, and traditional treatments. We will also review the biological characteristics and the latest therapies for PSC. These novel therapies show promise in the management of PSC, and the outcomes of investigative trials will hopefully reveal a variety of treatment options for patients with PSC.

Analysis of targeted somatic mutations in pleomorphic carcinoma of the lung using next-generation sequencing technique

BACKGROUND

Pleomorphic carcinoma (PC) of the lung is a rare type of lung cancer with aggressive characteristics and a poor prognosis. Because it is rare, the molecular characteristics of PC remain unclear.

METHODS

A gene mutation analysis was performed using next-generation sequencing (NGS) in patients with PC of the lung who had undergone surgical resection.

RESULTS

A total of nine patients were enrolled in the study. All the patients were male and eight had a history of smoking. Eight tumors contained spindle cells and three contained giant cells. Mutations considered significant were found in eight of the nine patients: in TP53 in five patients, in MET in two patients, and in ALK, ERBB2, PIK3CA, APC, NF1, and CDKN2A in one patient each. No EGFR mutation was detected in our analysis. Co-mutations were detected in three patients: TP53 with MET and NF1, TP53 with ERBB2, and PIK3CA with CDKN2A.

CONCLUSIONS

TP53 mutations were detected most frequently in PC of the lung with NGS analysis. Different co-mutations were seen in several specimens.

KEY POINTS

Significant findings of the study This study demonstrates that mutations in the TP53 gene are frequently found and co-mutations are sometimes found in pleomorphic carcinoma of the lung using genomic profiling analysis. What this study adds Our results will help to analogize the genetic characteristics and potential target of molecular-targeted agents of pleomorphic carcinoma of the lung.

Characteristics and Response to Crizotinib in ALK-Rearranged, Advanced Non-Adenocarcinoma, Non-Small Cell Lung Cancer (NA-NSCLC) Patients: a Retrospective Study and Literature Review

BACKGROUND

Oncogenic fusion genes consisting of echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) can be detected in 5-7% of lung adenocarcinoma cases. The prevalence of ALK rearrangement in non-adenocarcinoma, non-small cell lung cancers (NA-NSCLC) is currently unknown. In addition, the efficacy of crizotinib in these patients has not been well established.

OBJECTIVES

The aim of this study was to investigate the prevalence of ALK rearrangement in NA-NSCLC patients and the therapeutic efficacy of crizotinib in these patients.

METHODS

We included NA-NSCLC patients who were tested for the presence of ALK rearrangement in our institution from January 2013 to May 2018. The effectiveness of crizotinib in ALK-positive patients was retrospectively analyzed. A literature review was performed and eligible previously published cases were analyzed in combination with our data.

RESULTS

A total of 4662 patients were screened and 1696 NA-NSCLC patients were tested for the presence of ALK rearrangement during the study period. Thirty-two positive patients were identified (1.9%, 95% CI, 1.2-2.5%). A statistically higher percentage of younger (58.0 vs. 63.0, p = 0.01), female patients (53.1% vs. 10.8%, p < 0.01) who were non-smokers (71.9% vs. 40.6%, p < 0.01) and whose tumors contained adenocarcinoma components (34.4% vs. 6.1%, p < 0.01) were observed in the ALK-positive group. Eighteen patients were excluded from the study and 14 eligible patients were included for survival analysis. The median duration of crizotinib treatment (MDT) as a proxy for progression-free survival of the 14 eligible patients in our institution was 6.0 months (95% CI, 1.2-10.8 months). We combined our data with sporadic cases from 16 previous publications (total n = 37) and found that the MDT was 7.0 months (95% CI, 6.0-8.0 months).

CONCLUSIONS

Our study suggests the opportunity to test ALK rearrangement in NA-NSCLC patients, especially in younger, female, non-smoking patients containing adenocarcinoma components. Crizotinib provides an option for the treatment of NA-NSCLC patients who have an ALK rearrangement.

Uncommon Types of Lung Carcinoma With Mixed Histology: Sarcomatoid Carcinoma, Adenosquamous Carcinoma, and Mucoepidermoid Carcinoma

CONTEXT

- Lung tumors are histologically heterogeneous, but classification of lung carcinoma has prognostic impact and increasingly, specific molecular correlates.

OBJECTIVE

- To update the gross, microscopic, and molecular pathology of unusual lung carcinomas to assure accurate classification. In entities with mixed histology, the recognition of specific features or rare patterns is critical to diagnosis. These diagnoses can identify tumors with aggressive clinical behavior, and diagnostic pitfalls can therefore result in underdiagnosis of these already rare entities. Incorrect classification of more indolent tumors into the more aggressive categories can also occur. In the area of molecular pathology, these unusual tumors have a specific spectrum of molecular alterations.

DATA SOURCES

- PubMed searches for lung and sarcomatoid carcinoma, pleomorphic carcinoma, blastoma, carcinosarcoma, and adenosquamous and mucoepidermoid carcinoma were undertaken and this information was integrated with clinical experience of the author.

CONCLUSIONS

- These uncommon carcinomas have specific clinicopathologic features, and attention to their gross and microscopic pathology leads to classification with important associated molecular findings.

Whole transcriptome targeted gene quantification provides new insights on pulmonary sarcomatoid carcinomas

Pulmonary sarcomatoid carcinomas (PSC) are a rare group of lung cancer with a median overall survival of 9–12 months. PSC are divided into five histotypes, challenging to diagnose and treat. The identification of PSC biomarkers is warranted, but PSC molecular profile remains to be defined. Herein, a targeted whole transcriptome analysis was performed on 14 PSC samples, evaluated also for the presence of the main oncogene mutations and rearrangements. PSC expression data were compared with transcriptome data of lung adenocarcinomas (LUAD) and squamous cell carcinomas (LUSC) from The Cancer Genome Atlas. Deregulated genes were used for pathway enrichment analysis; the most representative genes were tested by immunohistochemistry (IHC) in an independent cohort (30 PSC, 31 LUAD, 31 LUSC). All PSC cases were investigated for PD-L1 expression. Thirty-eight genes deregulated in PSC were identified, among these IGJ and SLMAP were confirmed by IHC. Moreover, Forkhead box signaling and Fanconi anemia pathways were specifically enriched in PSC. Finally, some PSC harboured alterations in genes targetable by tyrosine kinase inhibitors, as EGFR and MET. We provide a deep molecular characterization of PSC; the identification of specific molecular profiles, besides increasing our knowledge on PSC biology, might suggest new strategies to improve patients management.

Lung spindle cell carcinoma harbouring a constitutively active epidermal growth factor receptor mutation

Lung spindle cell carcinoma is a rare lung tumour with a poor prognosis, and its standard therapy has not been established. Furthermore, little work has been conducted on the genetic characteristics of lung spindle cell carcinomas. Here, we report an 82-year-old woman who was referred to our hospital due to a fever and dyspnoea. Chest computed tomography demonstrated a 75-mm mass surrounded by infiltrates and atelectasis in the right upper lobe. She was eventually diagnosed with lung spindle cell carcinoma corresponding to clinical stage IVB (cT4N2M1c(ADR)). A genetic study indicated that epidermal growth factor receptor (EGFR) exon 19 was deleted in the tumour cells. She received gefitinib as first-line therapy. However, no significant effect was observed, and she died of respiratory failure 89 days after the initial admission. To our knowledge, this is the first case of spindle cell carcinoma of the lung in which a sensitizing EGFR mutation is detected.

Pulmonary Sarcomatoid Carcinomas: A Review

Pulmonary sarcomatoid carcinomas belong to a group of neoplasms that remain incompletely understood. They are rare tumors of the bronchopulmonary system that incorporate a wide range of neoplasms that by definition contain a sarcomatoid component characterized by spindle or giant cells. Such classification has led to a heterogenous tumor category that includes neoplasms with different clinical, morphologic, and prognostic features. To date, the histopathologic diagnosis of pulmonary sarcomatoid carcinomas does not require the use of ancillary testing and is based on light microscopic criteria alone. However, with recent advances in immunohistochemical and molecular methods, it is becoming increasingly clear that pulmonary sarcomatoid carcinomas represent poorly differentiated or "dedifferentiated" variants of conventional non-small cell carcinomas with similar immunophenotype and molecular signatures. This review summarizes the latest insights and concepts of these unusual tumors and outlines future directions with emphasis on tumor classification and patient management.

Anaplastic lymphoma kinase (ALK)-rearranged pulmonary pleomorphic carcinoma successfully treated with crizotinib

Pulmonary pleomorphic carcinoma (PPC) is rare, and the response of patients to conventional chemotherapy is very poor. Here we present a patient with anaplastic lymphoma kinase (ALK)-rearranged advanced PPC treated with crizotinib. Computed tomography revealed a mass in the left upper lung of a nonsmoking 60-year-old woman. Pathological findings using resected tissue were consistent with PPC stage 1A, T1bN0M0. Although the patient received adjuvant radiotherapy, the disease relapsed, quickly progressed, and remained PPC according to analysis of biopsied tissue. Although negative for epidermal growth factor receptor mutations, ALK rearrangements were detected in adenocarcinoma and spindle-cell components. The patient received crizotinib therapy and achieved a partial response for 7 months. This case indicates that patients with PPC, particularly those with adenocarcinoma, may harbor an epithelial component with the ALK rearrangement. Although the progression-free survival of patients treated with crizotinib is limited, they may obtain more benefit compared with conventional chemotherapy.

PD-L1 expression in pleomorphic, spindle cell and giant cell carcinoma of the lung is related to TTF-1, p40 expression and might indicate a worse prognosis

Lung sarcomatoid carcinoma of the lung is a rare tumor with a poor prognosis. More than 90% of them are pleomorphic, spindle cell and giant cell carcinoma (PSCGCC). This rare subtype of lung cancer is thought to be more resistant to chemotherapy, and a small subset of them seems to exhibit targetable mutations. Immunotherapy against PD1/PDL-1 is a new emerging treatment, and might be of interest in PSGSCC because they frequently express PD-L1. The aim of our work is to evaluate PD1 and PDL-1 expression in a surgical series of lung PSCGCC and their relationship with morphological and immunohistochemical parameters and prognosis. Thirty-six patients who underwent surgical resection of a PSGSCC were included. PD-L1 (E1L3N) expression on tumor cells and PD1 (NAT105) expression by tumor infiltrating lymphocytes (TILs) were performed by immunohistochemistry. Results were compared to immunohistochemistry tests of TTF1, Napsin A, p40 and to molecular study of EGFR, KRAS, BRAF and HER2. Seventy-five % of PSCGCC were considered as positive for PD-L1.PD-L1 expression in PSGSCC is associated with TTF-1 and/or Napsin A expression (47.2%, p = 0.039). Few p40 positive PSCGCC expressed PD-L1 (8.3%, p = 0.013). PD1 expression was not related to TTF-1 and/or Napsin A expression (p = 0.47), p40 expression (p = 0.68) or survival (p = 0.14). PD-L1 or PD1 expression were not related to the age, gender, pT, pN, stage, visceral pleura invasion, histopathological subtype, the presence of giant cell component, the predominance of sarcomatoid component, and the presence of EGFR or BRAF or HER2 or PIK3CA mutation (p>0.05). PD-L1 expression was correlated with a worse overall survival in PSCGCC (p = 0.045). PD-L1 expression is frequent in PSCGCC and might be associated with the expression of adenocarcinoma markers (TTF-1, Napsin A) or the lack of expression of squamous cell carcinoma marker (p40).

"Sarcomatoid" carcinomas of the lung: a clinicopathological study of 86 cases with a new perspective on tumor classification

Pulmonary sarcomatoid carcinoma includes a heterogenous group of tumors difficult to diagnose and treat. We report the clinicopathological features of 86 such tumors, including 74 pleomorphic and 12 spindle cell carcinomas, and propose a novel approach to the classification of these neoplasms in an attempt to better guide patient management. The patients were 47 men and 39 women aged 36 to 87 years (mean, 63 years) who primarily presented with shortness of breath, cough, and chest pain. Eighty-six percent of patients had a smoking history. Histologically, the pleomorphic carcinomas consisted of spindle and/or giant cells with varying proportions of conventional non-small cell carcinoma in the form of adenocarcinoma (n=29), squamous cell carcinoma (n=10), or large cell carcinoma (n=18); 17 cases contained a mix of spindle and giant cells only. The 12 spindle cell carcinomas consisted of spindle cells only. Based on the combined histopathologic and immunohistochemical features of these tumors, we were able to reanalyze the spectrum of these lesions and reclassify them accordingly. Statistical analysis revealed an overall survival at 3, 5, and 10 years of 42.9%, 34.6%, and 23.5%, respectively, and a median survival of 15 months. Log-rank test showed that in multivariate analysis, only pathological T stage was a factor associated with prognosis. The current classification of pulmonary sarcomatoid carcinomas precludes optimal triaging of these tumors with the risk of denying patients access to novel treatment. Our proposal for a reclassification of these tumors would more accurately guide patient management and facilitate targeted therapies.

Basic Molecular Pathology and Cytogenetics for Practicing Pathologists: Correlation With Morphology and With a Focus on Aspects of Diagnostic or Therapeutic Utility

Morphology, as confronted in the everyday practice, often correlates with specific molecular features, which have important implications not only in pathogenesis and in diagnosis but also in prognosis and therapy. Thus, it is important that the classical pathology includes a sound knowledge of molecular aspects of disease. These molecular concepts are complex and not easily understood by all engaged in the routine practice of histopathology. Thus, the aim of this review is to present a summary of most of the necessary concepts for pathologists involving molecular pathology and genetics, beginning from basic definitions and mechanisms to major abnormalities and the methodology to detect them, correlating at the same time, the specific morphologic features associated with every abnormality.

The impact of immunohistochemistry on the classification of lung tumors

INTRODUCTION

To highlight the role of immunohistochemistry to lung cancer classification on the basis of existing guidelines and future perspectives.

AREAS COVERED

Four orienting key-issues were structured according to an extensive review on the English literature: a) cancer subtyping; b) best biomarkers and rules to follow; c) negative and positive profiling; d) suggestions towards an evidence-based proposal for lung cancer subtyping. A sparing material approach based on a limited number of specific markers is highly desirable. It includes p40 for squamous cell carcinoma ('no p40, no squamous'), TTF1 for adenocarcinoma, synaptophysin for neuroendocrine tumors and vimentin for sarcomatoid carcinoma. A close relationship between genotype and phenotype also supports a diagnostic role for negative profiles. Expert commentary: Highly specific and sensitive IHC markers according to positive and negative diagnostic algorithms seem appropriate for individual patients' lung cancer subtyping.