Among thyroid papillary carcinomas (PTCs), the follicular variant is the most common and includes encapsulated forms (EFVPTCs). Noninvasive EFVPTCs have very low risk of recurrence or other adverse events and have been recently proposed to be designated as noninvasive follicular thyroid neoplasm with papillary-like nuclear features or NIFTP, thus eliminating the term carcinoma. This proposal is expected to significantly impact the risk of malignancy associated with the currently used diagnostic categories of thyroid cytology. In this study, we analyzed the fine needle aspiration biopsy (FNAB) cytology features of 96 histologically proven NIFTPs and determined how the main nuclear features of NIFTP correlate between cytological and histological samples. Blind review of FNAB cytology from NIFTP nodules yielded the diagnosis of "follicular neoplasm" (Bethesda category IV) in 56% of cases, "suspicious for malignancy" (category V) in 27%, "atypia of undetermined significance/follicular lesion of undetermined significance" (category III) in 15%, and "malignant" (category VI) in 2%. We found good correlation (κ=0.62) of nuclear features between histological and cytological specimens. NIFTP nuclear features (size, irregularities of contours, and chromatin clearing) were significantly different from those of benign nodules but not from those of invasive EFVPTC. Our data indicate that most of the NIFTP nodules yield an indeterminate cytological diagnosis in FNAB cytology and nuclear features found in cytology samples are reproducibly identified in corresponding histology samples. Because of the overlapping nuclear features with invasive EFVPTC, NIFTP cannot be reliably diagnosed preoperatively but should be listed in differential diagnosis of all indeterminate categories of thyroid cytology.

Neuroendocrine tumors of the lung (Lu-NETs) embrace a heterogeneous family of neoplasms classified into four histological variants, namely typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC). Defining criteria on resection specimens include mitotic count in 2 mm and the presence or absence of necrosis, alongside a constellation of cytological and histological traits including cell size and shape, nuclear features and overall architecture. Clinically, TC are low-grade malignant tumors, AC intermediate-grade malignant tumors and SCLC/LCNEC high-grade malignant full-blown carcinomas with no significant differences in survival between them. Homologous tumors arise in the thymus that occasionally have some difficulties in differentiating from the lung counterparts when presented with large unresectable or metastatic lesions. Immunohistochemistry (IHC) helps refine NE diagnosis at various anatomical sites, particularly on small-sized tissue material, in which only TC and small cell carcinoma categories can be recognized easily on hematoxylin & eosin stain, while AC and LCNEC can only be suggested on such material. The Ki-67 labeling index effectively separates carcinoids from small cell carcinoma and may prove useful for the clinical management of a metastatic disease to help the therapeutic decision-making process. Although carcinoids and high-grade neuroendocrine carcinomas in the lung and elsewhere make up separate tumor categories on molecular grounds, emerging data supports the concept of secondary high-grade NETs arising in the preexisting carcinoids, whose clinical and biological relevance will have to be placed into the proper context for the optimal management of these patients. In this review, we will discuss the selected, recent literature with a focus on current issues regarding Lu-NET nosology, i.e., classification, derivation and tumor evolution.

The TNM classification of malignant tumours is a mainstay tool in clinical practice and research for prognostic assessment of patients, treatment allocation and trial enrolment, as well as for epidemiological studies and data collection by cancer registries worldwide. Pathological TNM (pTNM) represents the pathological classification of a tumor, assigned after surgical resection or adequate sampling by biopsy, and periodical updates to the relative classification criteria are necessary to preserve its clinical relevance by integrating newly reported data. A structured approach has been put in place to fulfil this need and, based upon this process, the Eighth Edition of Union for International Cancer Control (UICC) TNM Classification of Malignant Tumours has been published, introducing many significant changes, including novel classification criteria for specific tumour types. In this review, we aim to describe the major changes introduced in the pTNM classification criteria and to summarize the evidence supporting these changes.

Typical (TCs) and atypical carcinoids (ACs) are defined based on morphological criteria, and no grading system is currently accepted to further stratify these entities. The 2015 WHO classification restricts the Ki-67 role to biopsy or cytology samples, rather than for prognostic prediction. We aimed to investigate whether values and patterns of Ki-67 alone would allow for a clinically meaningful stratification of lung carcinoids, regardless of histological typing. Ki-67 proliferation index and pattern (homogeneous versus heterogeneous expression) were assessed in a cohort of 171 TCs and 68 ACs. Cases were subdivided into three Ki-67 ranges (<4/4–9/≥10%). Correlations with clinicopathological data, univariate and multivariate survival analyses were performed. The majority of cases (61.5%) belonged to the <4% Ki-67 range; 25.1 and 13.4% had a proliferation index of 4–9% and ≥10%, respectively. The <4% Ki-67 subgroup was significantly enriched for TCs (83%, p < 0.0001); ACs were more frequent in the subgroup showing Ki-67 ≥ 10% (75%, p < 0.0001). A heterogeneous Ki-67 pattern was preferentially seen in carcinoids with a Ki-67 ≥10% (38%, p < 0.02). Mean Ki-67 values ≥4 and ≥10% identified categories of poor prognosis both in terms of disease-free and overall survival (p = 0.003 and <0.0001). At multivariate analysis, the two thresholds did not retain statistical significance; however, a Ki-67 ≥ 10% identified a subgroup of dismal prognosis even within ACs (p = 0.03) at univariate analysis. Here, we describe a subgroup of lung carcinoids showing brisk proliferation activity within the necrosis and/or mitotic count-based categories. These patients were associated with specific clinicopathological characteristics, to some extent regardless of histological subtyping.

ObjectivesTo assess the use of hyper-accuracy three-dimensional (HA3D TM ; MEDICS, Moncalieri, Turin, Italy) reconstruction based on multiparametric magnetic resonance imaging (mpMRI) and superimposed imaging during augmented-reality robot-assisted radical prostatectomy (AR-RARP). ConclusionOur results suggest that a HA3D virtual reconstruction of the prostate based on mpMRI data and real-time superimposed imaging allow performance of an effective AR-RARP. Potentially, this approach translates into better outcomes, as the surgeon can tailor the procedure for each patient.