Constant p.L424H Mutation in GTF2I in Micronodular Thymomas With Lymphoid Stroma: Evidence Supporting Close Relationship With Type A and AB Thymomas.

Micronodular thymoma with lymphoid stroma is a rare thymic neoplasm characterized by discrete nodules of epithelial tumor cells separated by abundant lymphoid stroma. The genetic features of micronodular thymoma with lymphoid stroma remain largely unexplored. Owing to the interference of abundant intratumoral, nonneoplastic lymphoid cells, a highly sensitive approach is necessary to study genetic changes in these tumors. In this study, we used a highly sensitive next-generation sequencing assay using the molecular barcoding Ion AmpliSeq HD technology to study the most commonly mutated genes in thymomas, including GTF2I, HRAS, NRAS, KRAS, and TP53. A total of 12 cases of micronodular thymomas with lymphoid stroma were tested, and 2 cases also had areas of type A thymoma in their tumor bed. Two micronodular thymic carcinomas with lymphoid stroma, a histological mimic of micronodular thymoma, were also included for comparison. Recurrent p.L424H mutations in GTF2I were found in all the cases of micronodular thymoma with lymphoid stroma but not in the cases of micronodular thymic carcinomas. In addition, 3 cases of micronodular thymoma with lymphoid stroma also had concomitant HRAS and/or KRAS mutations. Our study showed that p.L424H mutations in GTF2I is a constant genetic feature of micronodular thymoma with lymphoid stroma. This finding strongly suggests that micronodular thymoma with lymphoid stroma is closely related to type A and AB thymomas because they all share p.L424H mutations in GTF2I.

Molecular typing for detection of high-risk human papillomavirus is a useful tool for distinguishing primary bladder carcinoma from secondary involvement of uterine cervical carcinoma in the urinary bladder.

AIMS: For patients with carcinoma of the urinary bladder and uterine cervix, distinguishing between metastasis and a second primary carcinoma has significant prognostic and therapeutic implications. The aim of this study was to investigate the prevalence of high-risk human papillomavirus (HR-HPV) in cervical carcinoma with secondary involvement of the bladder and primary bladder carcinoma, in order to explore whether the detection of HR-HPV could help to differentiate between the two. METHODS AND RESULTS: Paired bladder and cervix carcinoma specimens from 37 patients with cervical carcinoma with bladder involvement, four patients with bladder carcinoma with uterine cervical involvement and two patients with double primaries were studied with quantitative multiplex polymerase chain reaction and chromogenic in-situ hybridization. Three hundred and seventy-five bladder carcinomas and 220 cervical carcinomas were analysed as controls. All cases of cervical carcinoma with bladder involvement showed concordant HR-HPV-positive patterns. The four cases of bladder carcinoma with uterine involvement were negative for HR-HPV. HR-HPV was detected in the cervical carcinoma but not in the bladder carcinoma of the patients with double primaries. HR-HPV was detected in 91.9% of cervical carcinomas but in none of the bladder carcinomas in the control group. CONCLUSIONS: Molecular typing for HR-HPV detection is useful to distinguish bladder carcinoma from secondary involvement of cervical carcinoma.

The importance of EGFR mutation testing in squamous cell carcinoma or non-small cell carcinoma favor squamous cell carcinoma diagnosed from small lung biopsies.

BACKGROUND: Adenosquamous carcinoma (ADSC) of the lung, a rare but aggressive subtype of non-small cell lung cancer (NSCLC), is defined as a carcinoma containing components of adenocarcinoma (ADC) and squamous cell carcinoma (SqCC). Mutations of epidermal growth factor receptor (EGFR) are found at a frequency of 15 to 44% in Asian ADSC, and EGFR tyrosine kinase inhibitors (EGFR-TKIs) are a more effective treatment for EGFR-mutated ADSC compared to chemotherapy. However, ADSC in small lung biopsies could be misdiagnosed as SqCC or non-small cell carcinoma (NSCC) favor SqCC due to undersampling, which may result in neglecting of EGFR mutation testing and affecting patients' clinical management, particularly in Asian patients that relatively have high prevalence of EGFR mutation. METHODS: A total of 148 small lung biopsy cases with pathological diagnosis of SqCC or NSCC favor SqCC were retrospectively enrolled. The frequency of EGFR mutations and the correlation between patients' EGFR mutation status and clinicopathological characteristics were evaluated. RESULTS: EGFR mutations were found in 8.8% (13 /148) of all cases with 5.2% (7/135) in SqCC and 46.2% (6/13) in NSCC favor SqCC. There were 7 (53.8%) L858R mutation, 4 (30.8%) exon 19 deletions, and 2 (15.4%) cases with coexistent L858R and T790 M mutations. Multivariate analysis showed that EGFR mutations were more prevalent in never-smokers (83.3% versus 16.7%, p = 0.006) and patients diagnosed as NSCC favor SqCC (46.2% versus 5.2%, p = 0.001). Moreover, 75% (3/4) of EGFR mutation-positive cases with subsequent surgical resection or rebiopsy were further diagnosed as ADSC. CONCLUSIONS: EGFR mutation testing should be performed in Asian patients with SqCC diagnosed from small lung biopsies, especially in never-smokers and patients with diagnosis of NSCC favor SqCC, which have a high probability of being ADSC.

Epstein-Barr Virus-Associated Pulmonary Carcinoma: Proposing an Alternative Term and Expanding the Histologic Spectrum of Lymphoepithelioma-like Carcinoma of the Lung.

Lymphoepithelioma-like carcinoma (LELC) of the lung is a rare Epstein-Barr virus (EBV)-associated carcinoma. It is histologically characterized by a syncytial growth pattern with marked lymphocytic infiltration that is indistinguishable from the histology observed in undifferentiated nasopharyngeal carcinomas. However, it has been noted that LELC can display nonclassic morphology and lack significant lymphocytic infiltration. In this study, we conducted a comprehensive clinicopathologic analysis of 61 patients with pulmonary LELC and performed automatic quantification of the lymphocytic infiltrate using the IHC Profiler software. We demonstrated that pulmonary LELCs have a morphologically continuous spectrum, ranging from classic poorly differentiated tumors with intense lymphocytic infiltration to nonclassic morphology with little lymphocytic infiltration. These EBV-associated tumors represent a distinct entity and usually occur in female and nonsmoking patients. Tumors with low lymphocytic infiltration can closely resemble nonkeratinizing squamous cell carcinoma and tend to be larger in size, have higher maximum standardized uptake values on radiography, and exhibit shorter times to recurrence than those with high lymphocytic infiltration. Through detailed pathologic examination, we observed several distinct morphologic features in pulmonary LELCs, including granulomatous inflammation, focal keratinization, spread through alveolar spaces, and lepidic spreading pattern. We also found that patients with tumors exhibiting granulomatous inflammation have favorable outcomes; however, spread through alveolar spaces did not significantly correlate with prognosis. As many of these "LELCs" do not resemble undifferentiated nasopharyngeal carcinoma or lymphoepithelioma, we propose using an alternative term, EBV-associated pulmonary carcinoma, to encompass the entire morphologic spectrum of this distinct disease entity.

Correction: Long term oncological outcome of thymoma and thymic carcinoma - an analysis of 235 cases from a single institution.

[This corrects the article DOI: 10.1371/journal.pone.0179527.].

Long term oncological outcome of thymoma and thymic carcinoma - an analysis of 235 cases from a single institution.

BACKGROUND AND OBJECTIVES: Thymoma has a variable long-term oncological outcome after surgical resection. Survival and tumor recurrence were analyzed to determine the predisposing factors for tumor recurrence. METHODS: A total of 235 patients who underwent surgery for thymoma or thymic carcinoma from December 1997 to March 2013 were analyzed using Masaoka staging system and World Health Organization (WHO) histological classification. Surgical intervention included extended thymothymectomy via median sternotomy and thymomectomy via thoracotomy/ video-assisted thoracoscopic surgery (VATS). RESULTS: The median duration of follow-up was 105 months (12-198 months). Among these 235 patients, recurrence was observed in 25 patients (10.7%). according to Masaoka stage I, IIA, IIB, III, IVA, IVB, recurrence rates were 1/65(1.5%), 8/106(7.5%), 1/32(3.1%), 6/20(30.0%), 8/10(80.0%), 1/1(100.0%), respectively. Disease or treatment-related mortality was observed in 13 patients. Overall survival rate was 94.4%. After univariate analysis, predisposing factors for tumor recurrence included Masaoka stage, WHO histologic type, tumor size, adjuvant therapy and margin status. CONCLUSIONS: Due to the indolent behavior of thymoma, tumor recurrence appears to be a better assessment of oncological outcome rather than survival. Factors associated with tumor recurrence include Masaoka stage, WHO histologic type, tumor size, adjuvant therapy and margin status.

Lymphedema-associated neutrophilic dermatosis: Two cases of localized Sweet syndrome on the lymphedematous lower limbs.

Neutrophilic dermatosis on the site of lymphedema is a rare condition and considered as a localized and less severe variant of Sweet syndrome. Only 13 cases of this variant have been reported after mastectomy for breast cancer in the English-language published work. However, this condition has never been described on the lower limbs or from other causes of lymphedema. Herein, we report two cases of localized Sweet syndrome on the lymphedematous lower limbs: one occurred after radical hysterectomy, bilateral pelvic lymph node dissection and radiotherapy for cervical cancer; the other developed after radiotherapy for malignant melanoma on the right groin. Based on clinical and histological features, we suggest the name "lymphedema-associated neutrophilic dermatosis" for this underrecognized disease entity.

Diagnostic algorithm for detection of targetable driver mutations in lung adenocarcinomas: Comprehensive analyses of 205 cases with immunohistochemistry, real-time PCR and fluorescence in situ hybridization methods.

OBJECTIVES: Analysis of the targetable driver mutations is now recommended in all patients with advanced lung adenocarcinoma. Molecular-based methods are usually adopted, however, along with the implementation of highly sensitive and/or mutation-specific antibodies, immunohistochemistry (IHC) has been considered an alternative method for identifying driver mutations in lung adenocarcinomas. MATERIALS AND METHODS: A total of 205 lung adenocarcinomas were examined for EGFR mutations and ALK and ROS1 rearrangements using real-time PCR, fluorescence in situ hybridization (FISH) and IHC in parallel. The performance of different commercially available IHC antibody clones toward targetable driver mutations was evaluated. The association between these driver mutations and clinicopathological characteristics was also analyzed. RESULTS: In 205 cases we studied, 58.5% were found to harbor EGFR mutations, 6.3% ALK rearrangements and 1.0% ROS1 rearrangements. Compared to molecular-based methods, IHC of EGFR mutations showed an excellent specificity but the sensitivity is suboptimal, while IHC of ALK and ROS1 rearrangements demonstrated high sensitivity and specificity. No significant difference regarding the performance of different antibody clones toward these driver mutations was observed, except that clone SP125 showed a higher sensitivity than 43B2 in the detection of p.L858R of EGFR. CONCLUSION: In circumstances such as poor quality of nucleic acids or low content of tumor cells, IHC of EGFR mutation-specific antibodies could be used as an alternative method. Patients negative for EGFR mutations are subjected to further analysis on ALK and ROS1 rearrangements using IHC methods. Herein, we proposed a lung adenocarcinoma testing algorithm for the application of IHC in therapeutic diagnosis.

Head and neck large cell neuroendocrine carcinoma should be separated from atypical carcinoid on the basis of different clinical features, overall survival, and pathogenesis.

According to the 2005 World Health Organization classification of head and neck tumors, neuroendocrine tumors can be subdivided into typical carcinoid, atypical carcinoid, and small cell carcinoma. Similar tumors diagnosed as large cell neuroendocrine carcinomas (LCNECs) in the lung are diagnosed as atypical carcinoids in the head and neck region. We studied neuroendocrine tumors and analyzed whether LCNEC should be separated from atypical carcinoid in the head and neck region. Twenty-three cases of primary head and neck neuroendocrine tumors were included and subdivided into typical carcinoid, atypical carcinoid, and small cell carcinoma according to the 2005 World Health Organization guidelines, and then LCNECs were separated from atypical carcinoids according to modified criteria using the Ki-67-labeling index and mitotic count. Clinical information and survival data were obtained, and immunohistochemical studies for p53 were conducted. The 5-year survival rates for the 2 typical carcinoids, 7 atypical carcinoids, 7 LCNECs, and 7 small cell carcinomas were 100.0%, 83.3%, 21.4%, and 20.8%, respectively (P=0.032). The LCNEC patients were older (mean age, 61 vs. 41 y; P=0.038), more commonly in advanced stage (stages III and IV 100% vs. 28.6%, P=0.01), with a poorer prognosis (5-year survival 21.4% vs. 83.3%, P=0.03), and more commonly had tumors overexpressing p53 (85.7% vs. 0%, P=0.005) as compared with atypical carcinoid patients. LCNECs should be separated from atypical carcinoids as a new entity of neuroendocrine carcinoma in the head and neck region. The new classification may provide better risk stratification and useful information for proper treatment.