Fine‐needle aspiration of metastatic prostatic neuroendocrine carcinomas: Cytomorphologic and immunophenotypic features

Cytomorphology, immunoprofile, and clinicopathologic correlation of metastatic prostatic carcinoma

It may be challenging to diagnose metastatic prostatic carcinoma (PC). This study focused on clinicopathologic correlation, and pitfalls of cytomorphology and immunostains of metastatic PCs. A total of 146 metastatic PCs including 134 (92%) PC without neuroendocrine differentiation-prostatic adenocarcinoma (PAC) and 12 (8%) with neuroendocrine differentiation (PC-NED) were retrieved. Triplicate tissue microarrays (TMA) of 54 surgically excised PCs were constructed for immunostains. Most cases showed Gleason 4 or 5 patterns. Nine percent of cases did not have a prior history of PC and 7% had 2 or more primary malignancies. PAC metastasized more commonly to lymph nodes (49%), and PC-NED metastasized more commonly to liver (58%). Cytologically, metastatic PCs show acini, cribriform, nest, and solid clusters. Most PACs showed conspicuous or prominent nucleoli. PC-NEDs showed typical cytologic features of low-grade or high-grade neuroendocrine neoplasm, or small cell carcinoma features. PACs could be immunoreactive to CDX2 (25%), CK20 (11%), NKX3.1 (99%), PSA (88%), PSAP (78%), and PSMA (92%). PC-NEDs were immunoreactive to neuroendocrine immunomarkers (CD56 [100%], chromogranin [67%], and synaptophysin [100%]) and p63 (25%), and lost expression of prostate-specific markers (NKX3.1, PSA, PSAP, and PSMA). Both PACs and PC-NEDs might be immunoreactive to CK7 (18% versus 33%), GATA3 (4% versus 0%), PAX8 (2% versus 50%, P < .05), and TTF1 (3% versus 57%, P < .05). It is critical to recognize these cytologic features and abbreviation of immunomarkers of metastatic PCs to avoid misinterpretation as metastatic carcinoma from nonprostate organs and inappropriate treatment. In addition, NED may be seen after hormone and chemoradiation treatment.

Metastatic Neuroendocrine Neoplasms of Unknown Primary: Clues from Pathology Workup

Simple Summary

While most neuroendocrine neoplasms are indolent and slow-growing tumors, subsets of cases will spread beyond the tissue of origin. Given the rather slow progress, some lesions are incidentally discovered as metastatic deposits rather than primary masses. In these cases, a biopsy is often taken to allow the pathologist to identify the tumor type and possibly the primary tumor site via microscopic examination. In this review, the authors present a simplified guide on how to approach metastatic neuroendocrine tumors from a pathologist’s perspective.

Abstract

Neuroendocrine neoplasms (NENs) are diverse tumors arising in various anatomical locations and may therefore cause a variety of symptoms leading to their discovery. However, there are instances in which a NEN first presents clinically as a metastatic deposit, while the associated primary tumor is not easily identified using conventional imaging techniques because of small primary tumor sizes. In this setting (which is referred to as a “NEN of unknown primary”; NEN-UP), a tissue biopsy is often procured to allow the surgical pathologist to diagnose the metastatic lesion. If indeed a metastatic NEN-UP is found, several clues can be obtained from morphological assessment and immunohistochemical staining patterns that individually or in concert may help identify the primary tumor site. Herein, histological and auxiliary analyses of value in this context are discussed in order to aid the pathologist when encountering these lesions in clinical practice.

Neuroendocrine Prostate Cancer (NEPC) progressing from conventional prostatic adenocarcinoma: factors associated with time to development of NEPC and survival from NEPC diagnosis-a systematic review and pooled analysis

PURPOSE

An often under-recognized late manifestation of prostate adenocarcinoma (PCa) is the development of treatment-related neuroendocrine prostate cancer (NEPC). The aim of this study is to identify the risk factors related to survival after NEPC diagnosis (NEPCS) and time from initial diagnosis of PCa to development of NEPC (TTNEPC).

PATIENTS AND METHODS

A literature search on NEPC was performed using databases such as MEDLINE and EMBASE. Studies were eligible if outcomes data (NEPCS and/or TTNEPC) were reported in patients with a prior history of PCa and histopathologically confirmed NEPC. NEPCS and TTNEPC were evaluated using the Cox regression model with the robust sandwich estimates of the covariance matrix.

RESULTS

There were 54 eligible publications, contributing 123 patients. The median TTNEPC was 20 months. In multivariable analyses, the Gleason score was significantly associated with shorter TTNEPC (hazard ratio [HR], 1.66; P = .032). The median NEPCS was 7 months. In multivariable analyses, the number of organs with metastatic disease at NEPC was significantly associated with shorter NEPCS (HR, 3.31; P = .001). Type of treatment after NEPC was significantly associated with longer NEPCS, with HRs of 0.66 (radiotherapy v palliative therapy; P = .034), 0.38 (chemotherapy v palliative therapy; P = .018), and 0.29 (chemoradiotherapy v palliative therapy; P = .012), respectively.

CONCLUSION

Treatment-related NEPC is an often under-recognized late manifestation of PCa with poor prognosis. Our study found that Gleason score was the only independent factor contributing to TTNEPC. Once NEPC is diagnosed, type of treatment and the number of organs with metastatic disease were the most important factors related to survival.

Prognostic significance of neuroendocrine differentiation in prostate adenocarcinoma

Much progress has been made toward an understanding of the development and progression of prostate cancer (PC) and the factors that drive the development of androgen independence. Neuroendocrine (NE) cells may provide an intriguing link between NE cell differentiation (NED) and tumor progression in PC. NED in PC generally confers a more aggressive clinical behavior and less favorable prognosis than conventional PC. In this article, we review the known functions of NE cells in PC and discuss the current knowledge on stimulation of cancer proliferation, invasion, apoptosis resistance, serum and immunohistochemical markers, and the prognostic significance of NED in human PC.

Lactate MRSI and DCE MRI as surrogate markers of prostate tumor aggressiveness

Longitudinal studies of lactate MRSI and dynamic contrast-enhanced MRI were performed at 4.7 T in two prostate tumor models grown in rats, Dunning R3327-AT (AT) and Dunning R3327-H (H), to determine the potential of lactate and the perfusion/permeability parameter Ak(ep) as markers of tumor aggressiveness. Subcutaneous AT (n = 12) and H (n = 6) tumors were studied at different volumes between 100 and 2900 mm(3) (Groups 1-5). Lactate concentration was determined using selective multiple quantum coherence MRSI with the phantom substitution method. Tumor enhancement after the administration of gadolinium diethylenetriaminepenta-acetic acid was analyzed using the Brix-Hoffmann model and the Ak(ep) parameter was used as a measure of tumor perfusion/permeability. Lactate was not detected in the smallest AT tumors (Group 1; 100-270 mm(3) ). In larger AT tumors, the lactate concentration increased from 2.8 ± 1.0 mm (Group 2; 290-700 mm(3)) to 8.4 ± 2.9 mm (Group 3; 1000-1340 mm(3)) and 8.2 ± 2.2 mm (Group 4; 1380-1750 mm(3) ), and then decreased to 5.0 ± 1.7 mm (Group 5; 1900-2500 mm(3)), and was consistently higher in the tumor core than in the rim. Lactate was not detected in any of the H tumors. The mean tumor Ak(ep) values decreased with increasing volume in both tumor types, but were significantly higher in H tumors. In AT tumors, the Ak(ep) values were significantly higher in the rim than in the core. Histological hypoxic and necrotic fractions in AT tumors increased with volume from 0% in Group 1 to about 20% and 30%, respectively, in Group 5. Minimal amounts of hypoxia and necrosis were found in H tumors of all sizes. Thus, the presence of lactate and heterogeneous perfusion/permeability are signatures of aggressive, metabolically deprived tumors.