Pulmonary neuroendocrine neoplasms with well differentiated morphology and high proliferative activity: illustrated by a case series and review of the literature

OBJECTIVES

Pulmonary neuroendocrine neoplasms (NENs) are subdivided in carcinoids and neuroendocrine carcinomas (small cell lung carcinoma and large cell neuroendocrine carcinoma (LCNEC)), based on the presence of necrosis and mitotic index (MI). However, it is unclear if tumors with well differentiated morphology but high proliferation rate should be regarded as LCNEC or as high grade carcinoids. In previous case series, a longer overall survival then expected in LCNEC has been suggested. We describe 7 of those cases analyzed for pRb expression and overall survival.

MATERIAL AND METHODS

Cases with well differentiated morphology, but MI > 10/2mm² and/or Ki-67 proliferation index >20% were selected based on pathology reports of consecutive NENs in our university medical center (Maastricht UMC+, 2007-2018) and confirmed by pathological review. Immunohistochemistry was performed to assess pRb expression.

RESULTS

Seven stage IV cases were included in this study. Median overall survival was 8 months (95% confidence interval 5-11 months). Cases with well differentiated morphology and preserved pRb expression (4/7) had a median overall survival of 45 months.

CONCLUSION

A subgroup of pulmonary NENs with well differentiated morphology but high proliferation rate likely exists. pRb staining might be helpful to predict prognosis, but clinical relevance remains to be studied.

[Pathological-anatomical diagnosis according to the German lung cancer guideline 2018]

The German S3-guideline on prevention, diagnosis, therapy and follow-up of lung cancer, published in February 2018, expands on the 2010 guideline to include a total of 19 recommendations and statements regarding the "processing of lung resection specimens (tumor resection specimens)", "processing of lymph nodes", "histo-pathological typing and immunophenotype", "extent of tumor growth in resection specimens", "resection margins" or "R-classification", "grade of malignancy (grading)", "regression grading" as well as the "examination of molecular targets". The statements regarding the analysis of molecular targets result from the diagnostic requirements of the current targeted therapy of advanced lung cancer. At the same time, a pathological-anatomical diagnosis according to the current S3-guideline fulfills all corresponding requirements in certified lung cancer centers.

Surgical management of lower-grade glioma in the spotlight of the 2016 WHO classification system

PURPOSE

According to the 2016 WHO classification lower-grade gliomas consist of three groups: IDH-mutated and 1p/19q co-deleted, IDH-mutated and IDH-wildtype tumors. The aim of this study was to evaluate the impact of surgical therapy for lower-grade gliomas with a particular focus on the molecular subgroups.

METHODS

This is a bi-centric retrospective analysis including 299 patients, who underwent treatment for lower-grade glioma between 1990 and 2016. All tumors were re-classified according to the 2016 WHO classification. Data concerning baseline and tumor characteristics, overall survival, different treatment modalities and functional outcome were analyzed.

RESULTS

A total of 112 (37.5%) patients with IDH-mutation and 1p/19q co-deletetion, 86 (28.8%) patients with IDH-mutation and 101 (33.8%) patients with IDH-wildtype tumors were identified. The median overall survival (mOS) differed significantly between the groups (p < 0.001). Surgical resection was performed in 226 patients and showed significantly improved mOS compared to the biopsy group (p = 0.001). Gross total resection (GTR) was associated with better survival (p = 0.007) in the whole cohort as well as in the IDH-mutated and IDH-wildtype groups compared to partial resection or biopsy. IDH-wildtype patients presented a significant survival benefit after combined radio-chemotherapy compared to radio- or chemotherapy alone (p = 0.02). Good clinical status (NANO) was associated with longer OS (p = 0.001).

CONCLUSION

The impact of surgical treatment on the outcome of lower-grade gliomas depends to a great extent on the molecular subtype of the tumors. Patients with more aggressive tumors (IDH-wildtype) seem to profit from more intensive treatment like GTR, multiple resections and combined radio-/chemotherapy.