Neuroendocrine Carcinoma of the Cervix: Review of a Series of Cases and Correlation With Outcome

The evolving landscape of immunohistochemistry in cervical and uterine carcinoma in gynecologic oncology: current status and future directions

Immunohistochemistry (IHC) has become an indispensable tool in routine gynecological pathology, particularly with the advancements in molecular understanding and histological classification of gynecological cancers. This evolution has led to new immunostainings for diagnostic and classification purposes. This review describes the diagnostic utility of IHC in gynecological neoplasms, drawing insights from literature reviews, personal experiences, and research findings. It delves into the application of IHC in resolving morphologically equivocal cases, emphasizing its role in achieving an accurate diagnosis. The selection of appropriate immunomarkers for common scenarios encountered in gynecological pathology aids pathologists in navigating complex cases. Specifically, we focus on cervical and endometrial malignancies, elucidating the molecular rationale behind the use of specific immunohistochemical markers. An updated overview of essential immunohistochemical markers provides knowledge for precise diagnosis and classification of gynecological cancers. This review serves as a valuable resource for clinicians and researchers involved in the management and study of gynecological malignancies, facilitating improved patient care and outcomes.

Ewing Sarcoma of the Female Genital Tract: Clinicopathologic Analysis of 21 Cases With an Emphasis on the Differential Diagnosis of Gynecologic Round Cell, Spindle, and Epithelioid Neoplasms

Ewing sarcoma is an uncommon neoplasm considered in the differential diagnosis of tumors with "small round cell" morphology, but its occurrence in the gynecologic tract has only been sporadically documented. Herein, we describe the largest cohort of Ewing sarcoma localized to the female genital tract to date, and emphasize their clinicopathologic resemblance to more common gynecologic neoplasms. Ewing sarcoma (n=21) was retrospectively identified from 5 institutions. The average patient age was 35 (range 6-61) years. Tumor sites included uterus (n=8), cervix (n=4), vulva (n=5), vagina (n=1), broad ligament (n=1), inguinal area (n=1), and pelvis (n=1). Nine of 18 cases in which slides were available for review demonstrated only classic round cell morphology, with the remainder showing a variable combination and prominence of variant ovoid/spindle or epithelioid appearance. Tumors showed diffuse membranous reactivity for CD99 (20/20) and were positive for NKX2.2 (8/8, diffuse) and cyclin D1 (7/7, of which 3/7 were patchy/multifocal and 4/7 were diffuse). They were negative for ER (0/6) and CD10 (0/6). Three cases were initially diagnosed as endometrial stromal sarcomas. EWSR1 rearrangement was confirmed in 20/21 by fluorescence in situ hybridization (n=15) and/or sequencing (n=8). Of the eight tumors that underwent sequencing, 6 harbored FLI1 , 1 ERG, and 1 FEV as the fusion partner. Of 11 patients with available follow-up, 5 died of disease, 1 developed lung metastases and 5 are alive with no evidence of disease. Ewing sarcoma of the gynecologic tract is a rare, aggressive entity that shares some morphologic and immunohistochemical features with other more common gynecologic neoplasms. In addition to the typical round cell appearance, variant spindled/ovoid to epithelioid morphology may also be observed and should prompt consideration of this entity with appropriate immunohistochemical and/or molecular studies.

Small cell neuroendocrine carcinoma of the cervix: From molecular basis to therapeutic advances

Small cell neuroendocrine carcinoma of the cervix (SCNECC) is an uncommon but aggressive uterine malignancy, the cause of which is generally associated with human papillomavirus (HPV) infection. A lack of clinical trials and evidence-based treatment guidelines poses therapeutic challenges to this rare tumor. At present, published data remain limited to case series and case reports. While clinical management has traditionally followed those of small cell neuroendocrine (SCNE) lung cancer relying on surgery, chemoradiation, and systemic chemotherapy, the prognosis remains dismal. Immune checkpoint inhibitors (ICIs), such as monoclonal antibodies that target programmed death-1 (PD-1) or programmed death-ligand 1 (PD-L1), atezolizumab and durvalumab have proven effective in extensive-stage SCNE lung cancer. Moreover, pembrolizumab has also proven beneficial effects when added onto chemotherapy in metastatic and recurrent HPV-associated non-SCNE cervical cancer. It holds promise to use ICIs in combination with chemoradiation to improve the clinical outcomes of patients with SCNECC. Future advances in our understanding of SCNECC biology - associated with the study of its genomic and molecular aberrations as well as knowledge from SCNE of lung and other extrapulmonary sites- would be helpful in discovering new molecular targets for drug development. Collaborative efforts and establishment of a SCNECC-specific biobank will be essential to achieve this goal.

A Nomogram Model Based on Neuroendocrine Markers for Predicting the Prognosis of Neuroendocrine Carcinoma of Cervix

BACKGROUND

Combining traditional clinical parameters with neuroendocrine markers to construct a nomogram model to predict the postoperative recurrence of neuroendocrine carcinoma of cervix (NECC).

METHODS

A total of 257 patients were included in this study. Univariate and multivariate Cox regression analyses were used to establish a nomogram model in the training cohorts, which was further validated in the validation cohorts. The calibration curve was used to conduct the internal and external verification of the model.

RESULTS

Overall, 41 relapse cases were observed in the training (23 cases) and validation (18 cases) cohorts. The univariate analysis preliminarily showed that FIGO stage, stromal invasion, nerve invasion, lymph vascular space invasion, lymph node involvement, cervical-uterine junction invasion and CgA were correlated with NECC recurrence. The multivariate analysis further confirmed that FIGO stage (p = 0.023), stromal invasion (p = 0.002), lymph vascular space invasion (p = 0.039) and lymph node involvement (p = 0.00) were independent risk factors for NECC recurrence, which were ultimately included in the nomogram model. In addition, superior consistency indices were demonstrated in the training (0.863, 95% CI 0.784-0.942) and validation (0.884, 95% CI 0.758-1.010) cohorts.

CONCLUSIONS

The established nomogram model combining traditional clinical parameters with neuroendocrine markers can reliably and accurately predict the recurrence risks in NECC patients.

Immunosensitivity and specificity of insulinoma-associated protein 1 (INSM1) for neuroendocrine neoplasms of the uterine cervix

OBJECTIVE

Previously, we reported that insulinoma-associated protein 1 (INSM1) immunohistochemistry (IHC) showed high sensitivity for neuroendocrine carcinoma of the uterine cervix and was an effective method for histopathological diagnosis, but that its specificity remained to be verified. Therefore, the aim was to verify the specificity of INSM1 IHC for a large number of non-neuroendocrine neoplasia (NEN) of the cervix.

METHODS

RNA sequences were performed for cell lines of small cell carcinoma (TCYIK), squamous cell carcinoma (SiHa), and adenocarcinoma (HeLa). A total of 104 cases of formalin-fixed and paraffin-embedded specimens, 16 cases of cervical NEN and 88 cases of cervical non-NEN, were evaluated immunohistochemically for conventional neuroendocrine markers and INSM1. All processes without antigen retrieval were performed by an automated IHC system.

RESULTS

The transcripts per million levels of INSM1 in RNA sequences were 1505 in TCYIK, 0 in SiHa, and HeLa. INSM1 immunoreactivity was shown only in the TCYIK. Immunohistochemical results showed that 15 cases of cervical NEN showed positive for INSM1; the positivity score of the tumor cell population and the stain strength for INSM1 were high. Two of the 88 cases of cervical non-NENs were positive for INSM1 in one case each of typical adenocarcinoma and squamous cell carcinoma. The sensitivity of INSM1 for cervical NEN was 94%; specificity, 98%; the positive predictive value, 88%; and the negative predictive value, 99%.

CONCLUSION

INSM1 is an adjunctive diagnostic method with excellent specificity and sensitivity for diagnosing cervical NEN. Higher specificity can be obtained if morphological evaluation is also performed.

Morphologic and Molecular Heterogeneity of Cervical Neuroendocrine Neoplasia: A Report of 14 Cases

Neuroendocrine neoplasms (NENs) of the cervix are rare aggressive tumors associated with poor prognosis and only limited treatment options. Although there is some literature on molecular underpinnings of cervical small cell neuroendocrine carcinomas (SCNECs), detailed morphologic and associated molecular characteristics of cervical NENs remains to be elucidated. Herein, 14 NENs (SCNEC: 6, large cell neuroendocrine carcinoma [LCNEC]: 6, neuroendocrine tumor [NET]: 2), including 5 admixed with human papillomavirus (HPV)-associated adenocarcinoma (carcinoma admixed with neuroendocrine carcinoma) were analyzed. All except 3 SCNECs were HPV16/18 positive. TP53 (3) and/or RB1 (4) alterations (3 concurrent) were only seen in SCNECs (4/6) and were enriched in the HPV16/18-negative tumors. The other most common molecular changes in neuroendocrine carcinomas (NECs) overlapping with those reported in the literature for cervical carcinomas involved PI3K/MAPK pathway (4) and MYC (4) and were seen in both SCNECs and LCNECs. In contrast, the 2 NETs lacked any significant alterations. Two LCNECs admixed with adenocarcinoma had enough material to sequence separately each component. In both pathogenic alterations were shared between the 2 components, including ERBB2 amplification in one and an MSH6 mutation with MYC amplification in the other. Overall, these findings suggest that cervical HPV-associated NETs are genomically silent and high-grade NECs (regardless of small or large cell morphology) share molecular pathways with common cervical carcinomas as it has been reported in the endometrium and are different from NECs at other sites. Molecular analysis of these highly malignant neoplasms might inform the clinical management for potential therapeutic targets.

Positive clinical outcomes following therapy with programmed cell death protein 1/programmed cell death ligand 1 inhibitors in neuroendocrine carcinoma of the cervix

Neuroendocrine carcinoma of the cervix (NECC) is a highly aggressive and rare gynecological malignancy with a poor prognosis. Despite aggressive local and systemic treatments, there are high rates of locoregional recurrence and distant metastases. Therefore, more potent treatments are required to manage NECC. In recent years, emerging immune checkpoint inhibitors, such as programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors, have been used in treating various solid tumors and provide a new direction for immune-targeted therapy for NECC. In this review, we summarize the biomarkers useful for the evaluation of the therapy with PD-1/PD-L1 inhibitors in patients with NECC and the clinical applications and prospects of monotherapy with PD-1/PD-L1 inhibitors and combinations with other therapies in patients with NECC. In some individual case reports, therapeutic strategies with PD-1/PD-L1 inhibitors showed good efficacy. Further studies are needed to confirm the possibility of using PD-1/PD-L1 inhibitors as a standard treatment strategy in NECC.

Dataset for the Reporting of Carcinoma of the Cervix: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

Cervical carcinoma remains one of the most common cancers affecting women worldwide, despite effective screening programs being implemented in many countries for several decades. The International Collaboration on Cancer Reporting (ICCR) dataset for cervical carcinoma was first developed in 2017 with the aim of developing evidence-based standardized, consistent and comprehensive surgical pathology reports for resection specimens. This 4th edition update to the ICCR dataset on cervical cancer was undertaken to incorporate major changes based upon the updated International Federation of Obstetricians and Gynecologists (FIGO) staging for carcinoma of the cervix published in 2018 and the 5th Edition World Health Organization (WHO) Classification of Female Genital Tumors published in 2020 and other significant developments in pathologic aspects of cervical cancer. This updated dataset was developed by a panel of expert gynecological pathologists and an expert gynecological oncologist, with a period of open consultation. The revised dataset includes "core" and "noncore" elements to be reported; these are accompanied by detailed explanatory notes and references providing the rationale for the updates. Standardized reporting using datasets such as this helps facilitate consistency and accuracy, data collection across different sites and comparison of epidemiological and pathologic parameters for quality and research purposes.

Low-grade Neuroendocrine Tumor of the Cervix: Report of 3 Cases of a Rare Neoplasm With Review of the Literature

Neuroendocrine neoplasms are uncommon in the cervix with almost all representing neuroendocrine carcinomas (NECs), either small cell or large cell type. Cervical low-grade neuroendocrine tumors (NETs) are extremely rare with few recent reports using contemporary modern diagnostic criteria. We report 3 cases of cervical NET in patients aged 32 to 57 yr and undertake a review of the literature. The first case was a pure grade 2 NET with pelvic lymph node metastasis (FIGO stage IIIC1). In the second case, a grade 1 NET was associated with high-grade squamous intraepithelial lesion, adenocarcinoma in situ and human papillomavirus (HPV)-associated adenocarcinoma and was FIGO stage IA1. The third patient underwent chemoradiotherapy following a biopsy diagnosis of a high-grade NEC which was radiologically FIGO stage IIIC1 and salvage hysterectomy revealed residual tumor with features of a grade 1 NET. In all cases, the NET was diffusely positive with at least 2 of the neuroendocrine markers chromogranin, synaptophysin, and CD56. The first tumor was p16 negative and the third exhibited block-type immunoreactivity. Molecular tests revealed high risk HPV types 18 and 51 in the third case but no HPV in the first case. p16 immunohistochemistry and HPV molecular testing was not available in the second case. The patients remain disease free with follow-up ranging from 2 to 8 yr. Since a combination of NET and NEC is extremely rare at all sites due to a different pathogenesis, we speculate that in the third case, the NET developed out of the NEC as a "maturation" phenomenon secondary to chemoradiotherapy.

[Revised German guidelines on the diagnosis and treatment of carcinoma of the uterine cervix-what's new for pathologists in 2021?]

In 2021, the 2015 German consensus guideline for the diagnosis and treatment of uterine cervical carcinoma was updated. The present article summarises the new recommendations for pathologists: the incorporation of the International Endocervical Adenocarcinoma Classification (IECC), which morphologically separates HPV-associated and non-HPV-associated adenocarcinomas, as well as the reporting of the prognostic relevant growth pattern of the adenocarcinoma of the endocervical subtype (Silva pattern). Histologically, multifocality has been defined as the presence of clearly invasive foci with a minimum distance between each focus of 0.2 cm. Because of its intratumoural heterogeneity, all carcinomas ≤ 2 cm in their largest dimension should be processed completely, and tumours > 2 cm should be processed with one block per centimetre of their greatest dimension. In cases of (radical) trachelectomy/hysterectomy, the distal vaginal resection margin and all parametrial tissue should be processed completely. Sentinel lymph nodes have to be processed completely by lamellation along its long axis in 0.2 cm intervals. Immunohistochemical ultrastaging is mandatory. Staging should be performed using the 2009 FIGO classification and 2017 TNM classification. Reporting the revised 2018 FIGO classification is optional. To date, molecular markers have not been relevant for prognostication and treatment decision making.

Neuroendocrine Neoplasia of the Female Genital Tract

Neuroendocrine neoplasia is relatively uncommon in the female genital tract (FGT) and occurs at any site, most often the ovary and cervix. A unified dichotomous nomenclature, introduced by the World Health Organization Classification of Tumors in all fifth edition volumes, divides neuroendocrine neoplasms (NENs) into well-differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The term carcinoid tumor is retained in the ovary and represents the commonest FGT NEN. NEC is most common in the cervix and is usually admixed with another human papillomavirus-associated epithelial neoplasm. Despite shared neuroendocrine differentiation, NET and NEC show diverse etiology, morphology, and clinical behavior.

Ubiquitin C-terminal hydrolase L1 promotes lymph node metastasis in small cell neuroendocrine carcinomas of the cervix

Objective

To screen for specific differentially expressed genes in small cell neuroendocrine carcinoma of the cervix (SCNEC) and to further explore their roles and mechanisms in tumor progression.

Methods

Differentially expressed genes in SCNEC compared with squamous cell carcinoma (SCC) and adenocarcinoma (AC) were screened by microarray and immunohistochemical analyses. The biological functions of the identified genes were examined in a SCNEC cell line using RNA interference and over-expression plasmid-transfection technologies. Co-expression network analysis and immunoprecipitation technology were used to explore the potential mechanisms.

Results

Compared with SCC and AC, UCHL1 (encoding ubiquitin C-terminal hydrolase L1) was identified as a specific differentially expressed gene in SCNEC, which was positively related to lymph node metastasis (LNM). Migration and invasion of SCNEC tumor cells were induced by UCHL1 over-expression and suppressed by UCHL1 down-regulation, as shown by scratch and transwell invasion assays. Co-expression network analysis suggested that Prospero homeobox protein 1 (PROX1) might interact with UCHL1, and in vivo immunoprecipitation and western blots verified that levels of ubiquitinated PROX1 were significantly decreased following UCHL1 overexpression.

Conclusion

UCHL1 is a potential biomarker of LNM in SCNEC. UCHL1 might promote SCNEC cell migration and invasion by reducing PROX1 ubiquitination.

SATB2 is expressed in neuroendocrine carcinoma of the uterine cervix

Neuroendocrine carcinoma (NEC) of the uterine cervix is less characterized than neuroendocrine neoplasms of other sites such as of the digestive system and the lung. Special AT-rich sequence-binding protein 2 (SATB2) recently emerged as a marker of well-differentiated neuroendocrine tumors of the lower gastrointestinal (GI) tract. Among NECs, SATB2 is more frequently expressed in cutaneous Merkel cell carcinoma than in NEC of other anatomical sites. In our study, we performed an immunohistochemical study of SATB2 in 16 NECs of the uterine cervix, where the expression of these markers is still undefined. SATB2 was expressed in 12/16 cervical NECs (75%), with 7/16 cases (44%) showing SATB2 positivity in ≥ 50% of cells. In 7 cervical NECs associated with a non-neuroendocrine component, the expression of SATB2 was restricted to the neuroendocrine component. SATB2 was positive in all cases that expressed CDX2 (n = 7) and TTF1 (n = 5), with no evident association with p16 and p53. Our study demonstrated that SATB2 is often expressed in NECs of the uterine cervix. This information should be taken into account when assessing the origin of a NEC.

Expression and clinical significance of a new neuroendocrine marker secretagogin in cervical neuroendocrine carcinoma

AIMS

To explore the expression of secretagogin (SCGN) in neuroendocrine carcinoma of the uterine cervix and analyse its relationship with clinicopathological characteristics and prognosis.

METHODS

From January 2010 to December 2017, 44 patients with cervical neuroendocrine carcinoma undergoing surgery were included in the study group, and 55 patients with cervical non-neuroendocrine carcinoma (including 30 cases of cervical squamous cell carcinoma and 25 cases of cervical adenocarcinoma) undergoing surgery were included in the control group. Immunohistochemical staining of SCGN was performed in both groups and compared with three common neuroendocrine markers, chromogranin A, synaptophysin (Syn) and CD56 in the study group. Detailed clinicopathological data of the two groups were analysed, and the patient survival in the study group was followed up.

RESULTS

The positive expression of SCGN in cervical neuroendocrine carcinoma, cervical adenocarcinoma and squamous cell carcinoma was 65.9% (29/44), 8% (2/25) and 0%, respectively. The positive expression of SCGN in cervical neuroendocrine carcinoma was significantly higher than that in cervical adenocarcinoma and squamous cell carcinoma (χ²=44.5, p<0.001). There were no statistical differences among the positive expression of SCGN and three common neuroendocrine markers (p>0.05 for all). The intensity of SCGN staining in patients with cervical neuroendocrine carcinoma with lymph node metastasis was significantly higher than that in patients without lymph node metastasis (p=0.020). However, there was no significant association between SCGN expression and survival among patients with cervical neuroendocrine carcinoma (p=0.633).

CONCLUSIONS

SCGN is a new neuroendocrine marker for cervical neuroendocrine carcinoma, whose expression correlates with lymph node metastasis.

Diagnostic value of four neuroendocrine markers in small cell neuroendocrine carcinomas of the cervix: a meta-analysis

Small cell neuroendocrine carcinoma of the cervix (SCNECC) is a highly invasive cervical cancer. The immunohistochemical criteria is an important aspect for assistant diagnosis of SCNECC. However, which markers can be appropriate selection for diagnosing SCNECC were not determined. The aim was to systematically evaluate expression levels of four neuroendocrine markers (containing synaptophysin (Syn), neural cell adhesion molecules (CD56), neuron-specific enolase (NSE) and chromograninA (CgA)) and to find out the appropriate selection for diagnosing SCNECC. Four English and three Chinese libraries were retrieved between 1984 and 2020. 23 studies about NSE, 36 studies about Syn, 23 studies about CD56 and 36 studies about CgA (all studies containing 581 patients) were eligible for meta-analyses. The pooled positive expression percentages (95% CI; I²) were as follows: 84.84% (79.41–90.27%; 76.7%) for Syn, 84.53% (79.43–89.96%; 37.5%) for CD56, 77.94% (69.13–86.76%; 83.5%) for NSE, and 72.90% (67.40–78.86%; 59.7%) for CgA. The positive proportions (95% CI; I²) ranked top three of simultaneous expressions of two markers were 87.75% (82.03–93.87%, 33.3%) for Syn and CD56, 70.92% (50.50–87.68%, 82.7%) for Syn and NSE, 65.65% (53.33–76.98%, 73.5%) for Syn and CgA. This confirms that Syn and CD56 are reliable indicators for diagnosing SCNECC.

Neuroendocrine Carcinoma of the Uterine Cervix: A Clinicopathologic and Immunohistochemical Study with Focus on Novel Markers (Sst2-Sst5)

BACKGROUND

Gynecological neuroendocrine neoplasms (NENs) are extremely rare, accounting for 1.2-2.4% of the NENs. The aim of this study was to test cervical NENs for novel markers of potential utility for differential diagnosis and target therapy.

METHODS

All cases of our center (n = 16) were retrieved and tested by immunohistochemistry (IHC) for 12 markers including markers of neuroendocrine differentiation (chromogranin A, synaptophysin, CD56), transcription factors (CDX2 and TTF1), proteins p40, p63, p16INK4a, and p53, somatostatin receptors subtypes (SST2-SST5) and the proliferation marker Ki67 (MIB1).

RESULTS

All cases were poorly differentiated neuroendocrine carcinomas (NECs), 10 small cell types (small cell-neuroendocrine carcinomas, SCNECs) and 6 large cell types (large cell-neuroendocrine carcinomas, LCNECs); in 3 cases a predominant associated adenocarcinoma component was observed. Neuroendocrine cancer cells expressed at least 2 of the 3 tested neuroendocrine markers; p16 was intensely expressed in 14 (87.5%) cases; SST5 in 11 (56.25%, score 2-3, in 9 cases); SST2 in 8 (50%, score 2-3 in 8), CDX2 in 8 (50%), TTF1 in 5 (31.25%), and p53 in 1 case (0.06%). P63 and p40 expressions were negative, with the exception of one case that showed moderate expression for p63.

CONCLUSIONS

P40 is a more useful marker for the differential diagnosis compared to squamous cell carcinoma. Neither CDX2 nor TTF1 expression may help the differential diagnosis versus potential cervical metastasis. P16 expression may suggest a cervical origin of NEC; however, it must be always integrated by clinical and instrumental data. The expression of SST2 and SST5 could support a role for SSAs (Somatostatin Analogues) in the diagnosis and therapy of patients with cervical NECs.

Invasive stratified mucin-producing carcinoma (i-SMILE) of the uterine cervix: report of a case series and review of the literature indicating poor prognostic subtype of cervical adenocarcinoma

PURPOSE

Invasive stratified mucin-producing carcinoma (i-SMILE) represents a recently recognized subtype of cervical adenocarcinoma (AC) developing in a background of a stratified mucin-producing intraepithelial lesion (SMILE). Clinical and prognostic data on i-SMILE are limited.

METHODS

We report a series of five cases with histopathological, immunohistochemical (p16) and PCR analyses. The cases as well as the patients previously published in the literature were reviewed for follow-up information.

RESULTS

Thirteen cases were identified. The mean age of 47.1 years (range 34-66) was not different from the usual type of cervical AC. 10/13 cases presented with tumors > 2 cm and a polypoid-exophytic appearance. Regardless of tumor size and stage of the disease, 7 out of 11 patients developed recurrent disease after a mean of 7.8 months (range 6 weeks-36 months). Five patients developed distant metastases (three of them in the lungs). Five out of the 11 informative cases died of the disease. All reported cases were positive for high-risk HPV (mainly HPV type 18) and associated with p16-overexpression.

CONCLUSION

i-SMILE represent a distinct subtype of invasive endocervical AC, associated high-risk HPV infection and strong p16-overexpression. Clinically, i-SMILE may represent an aggressive tumor with early recurrent disease and substantial risk of distant metastatic disease, especially to the lungs.

Next-generation Sequencing Reveals Recurrent Somatic Mutations in Small Cell Neuroendocrine Carcinoma of the Uterine Cervix

Small cell neuroendocrine carcinoma (SCNEC) of the uterine cervix is a rare but extremely aggressive tumor. While high-risk human papillomavirus (HPV) is involved at an early stage of oncogenesis in many tumors, additional driving events have been postulated to facilitate the progression of SCNECs. Identification of oncogenic drivers could guide targeted therapy of this neoplasm. Clinicopathologic features of 10 cervical SCNECs are reported. Analyses included immunohistochemical evaluation of p16, p53, synaptophysin, and chromogranin expression; in situ hybridizations and polymerase chain reaction for high-risk HPV and/or HPV 18; and next-generation sequencing based on a 637-gene panel. The patients ranged in age from 28 to 68 years (mean, 45.6 y; median, 40.5 y). All tumors had diffuse p16 and synaptophysin expression. All but 1 tumor was positive for chromogranin (extent of staining ranged from focal to diffuse). HPV 18 was detected in 6 tumors and HPV 35 in 1 tumor. At least 1 driver mutation was detected in 8 tumors. Four cases harbored TP53 somatic mutations, 3 of which correlated with an aberrant p53 staining pattern. Four PIK3CA mutations (p.G106A, p.N345T, p.E545K, and p.E545D) were detected in 3 tumors, 2 of which also harbored TP53 mutations. Oncogenic driver mutations involving KRAS, Erbb2, c-Myc, NOTCH1, BCL6, or NCOA3 were detected in 4 tumors. Mutations in caretaker tumor suppressors PTEN, RB1, BRCA1, BRCA2, and ARID1B were also identified in 4 tumors that commonly coharbored activating oncogenic mutations. Targeted next-generation gene sequencing identified genetic alterations involving the MAPK, PI3K/AKT/mTOR, and TP53/BRCA pathways in SCNECs. The presence of genetic alterations that are amenable to targeted therapy in SCNECs offers the potential for individualized management strategies for treatment of this aggressive tumor.

Neuroendocrine Tumors of the Fallopian Tube: Report of a Case Series and Review of the Literature

Primary neuroendocrine tumors of the fallopian tube are extremely rare with a few reported cases of high-grade neuroendocrine carcinoma and a single report of a carcinoid tumor arising in a teratoma. We report 4 cases of probable primary neuroendocrine tumors of the fallopian tube (2 carcinoid tumors/low-grade neuroendocrine tumors and 2 high-grade neuroendocrine carcinomas) in patients aged 49 to 71. These represent the first reported cases of primary tubal carcinoid tumor unassociated with a teratoma. We review the published literature regarding primary neuroendocrine tumors of the fallopian tube and speculate on the possible histogenesis of these neoplasms.

Imaging and staging of neuroendocrine cervical cancer

Neuroendocrine cervical cancer (NECC) is a rare and aggressive subtype of cervical cancer, accounting for less than 2% of cervical tumors. They are divided into low-grade and high-grade tumors. High-grade NECC is associated with human papillomavirus (HPV) 18 and to a smaller extent type 16. The most common molecular alterations in NECC include PIK3CA, KRAS, and TP53 mutations. Immunohistochemical staining for CD56, synaptophysin, and chromogranin is a helpful tool in the diagnosis. NECCs pose a significant clinical and therapeutic challenge because of their aggressive nature which is explained by their tendency towards early nodal and hematogenous spread. They have a median survival of 21-22 months, compared to 10 years in cervical squamous cell carcinomas. NECCs have a homogeneous high T2 signal intensity, homogeneous contrast enhancement and lower ADC values in MRI, compared to non-neuroendocrine tumors of the cervix. It is recommended to treat NECC with a multimodality therapeutic approach combining radical hysterectomy, systemic chemotherapy, and radiotherapy. The objective of this manuscript is to address the pathogenesis of NECC, elaborate the role of radiological imaging in the diagnosis and staging of NECCs, evaluate their prognosis, and summarize the suggested management plans for this lethal disease.

Successful cisplatin-etoposide chemotherapy-based treatment of a primary small cell neuroendocrine carcinoma of the tonsil with multiple metastases: a case report

Extrapulmonary small cell neuroendocrine carcinoma (SNEC) is an extremely rare and highly malignant tumor with a poor prognosis. Multiple metastases of SNEC are even more rare, and patients with locally advanced and metastatic disease generally face a poor outcome. To date, only a few cases of SNEC have been reported. Here, we describe a rare case of a 70-year-old female patient with SNEC of the tonsil who presented with multiple metastases and had achieved a complete response (CR) of the primary lesion and cervical lymph nodes for more than 1 year after receiving palliative chemotherapy. Initially, the patient presented with a 2-month history of throat pain. Magnetic resonance imaging and computed tomography revealed a soft mass with moderate enhancement on the left tonsil, which was confirmed by incisional aspiration biopsy. She was additionally sent for a positron emission tomography scan to evaluate small metastases in the left cervical lymph node, right lung, multiple mediastinal lymph nodes, and the fourth lumbar (L4) vertebra body metastases. Histopathological examination of the SNEC confirmed a nested, typical endocrine appearance with small round cells containing ovoid-shaped nuclei and high mitotic activity. Immunohistochemically, the tumor cells were positive for cytokeratin 8/18+, synaptophysin+, CD56+, and Ki-67 (<50%). The patient received 6 cycles of cisplatin combined with etoposide and was subsequently placed under close observation (<12 months). To date, she has achieved a CR of the primary lesion and cervical lymph nodes. In summary, we have described a case of successful treatment after chemotherapy for SNEC and have elucidated professional knowledge regarding the relevant aspects of SNEC.

Multilayered heterogeneity as an intrinsic hallmark of neuroendocrine tumors

Neuroendocrine tumors (NETs) comprise a complex and highly heterogeneous group of neoplasms that can arise all over the body, originating from neuroendocrine cells. NETs are characterized by a general lack of symptoms until they are in advanced phase, and early biomarkers are not as available and useful as required. Heterogeneity is an intrinsic, pivotal feature of NETs that derives from diverse causes and ultimately shapes tumor fate. The different layers that conform NET heterogeneity include a wide range of distinct characteristics, from the mere location of the tumor to its clinical and functional features, and from its cellular properties, to the core signaling and (epi)genetic components defining the molecular signature of the tumor. The importance of this heterogeneity resides in that it translates into a high variability among tumors and, hence, patients, which hinders a more precise diagnosis and prognosis and more efficacious treatment of these diseases. In this review, we highlight the significance of this heterogeneity as an intrinsic hallmark of NETs, its repercussion on clinical approaches and tumor management, and some of the possible factors associated to such heterogeneity, including epigenetic and genetic elements, post-transcriptional regulation, or splicing alterations. Notwithstanding, heterogeneity can also represent a valuable and actionable feature, towards improving medical approaches based on personalized medicine. We conclude that NETs can no longer be viewed as a single disease entity and that their diagnosis, prognosis and treatment must reflect and incorporate this heterogeneity.

Neuroendocrine carcinoma of the cervix: a systematic review of the literature

BACKGROUND

Neuroendocrine carcinoma of the cervix (NECC) is a rare variant of cervical cancer. The prognosis of women with NECC is poor and there is no standardized therapy for this type of malignancy based on controlled trials.

METHODS

We performed a systematic literature search of the databases PubMed and Cochrane Central Register of Controlled Trials to identify clinical trials describing the management and outcome of women with NECC.

RESULTS

Three thousand five hundred thirty-eight cases of NECC in 112 studies were identified. The pooled proportion of NECC among women with cervical cancer was 2303/163470 (1.41%). Small cell NECC, large cell NECC, and other histological subtypes were identified in 80.4, 12.0, and 7.6% of cases, respectively. Early and late stage disease presentation were evenly distributed with 1463 (50.6%) and 1428 (49.4%) cases, respectively. Tumors expressed synaptophysin (424/538 cases; 79%), neuron-specific enolase (196/285 cases; 69%), chromogranin (323/486 cases; 66%), and CD56 (162/267; 61%). The most common primary treatment was radical surgery combined with chemotherapy either as neoadjuvant or adjuvant chemotherapy, described in 42/48 studies. Radiotherapy-based primary treatment schemes in the form of radiotherapy, radiochemotherapy, or radiotherapy with concomitant or followed by chemotherapy were also commonly used (15/48 studies). There is no standard chemotherapy regimen for NECC, but cisplatin/carboplatin and etoposide (EP) was the most commonly used treatment scheme (24/40 studies). Overall, the prognosis of women with NECC was poor with a mean recurrence-free survival of 16 months and a mean overall survival of 40 months. Immune checkpoint inhibitors and targeted agents were reported as being active in three case reports.

CONCLUSION

NECC is a rare variant of cervical cancer with a poor prognosis. Multimodality treatment with radical surgery and neoadjuvant/adjuvant chemotherapy with cisplatin and etoposide with or without radiotherapy is the mainstay of treatment for early stage disease while chemotherapy with cisplatin and etoposide or topotecan, paclitaxel, and bevacizumab is appropriate for women with locally advanced or recurrent NECC. Immune checkpoint inhibitors may be beneficial, but controlled evidence for their efficacy is lacking.

Small-Cell Neuroendocrine Carcinoma of the Cervix Masquerading as a Cervical Fibroid: Report of a rare entity

Primary neuroendocrine tumours of the cervix are extremely rare, with an incidence of only 0.5-1%; as such, these entities can present a clinical and diagnostic challenge. Small-cell neuroendocrine carcinomas of the cervix are highly aggressive tumours that have a tendency to metastasise. We report a 44-year-old woman who presented to the Gynaecology Clinic of the Employees State Insurance Corporation Medical College & Hospital, Faridabad, India, in 2016 with menorrhagia. Based on a clinical examination, she was provisionally diagnosed with a cervical fibroid. However, a biopsy revealed features of a small-cell neuroendocrine carcinoma of the cervix which was subsequently confirmed via immunohistochemistry. An accurate diagnosis of a neuroendocrine carcinoma is vital as it forms the basis for treatment decisions as well as informing predictions for long-term survival.

Pathology of Neuroendocrine Tumours of the Female Genital Tract

Neuroendocrine tumours are uncommon or rare at all sites in the female genital tract. The 2014 World Health Organisation (WHO) Classification of neuroendocrine tumours of the endometrium, cervix, vagina and vulva has been updated with adoption of the terms low-grade neuroendocrine tumour and high-grade neuroendocrine carcinoma. In the endometrium and cervix, high-grade neoplasms are much more prevalent than low-grade and are more common in the cervix than the corpus. In the ovary, low-grade tumours are more common than high-grade carcinomas and the term carcinoid tumour is still used in WHO 2014. The term ovarian small-cell carcinoma of pulmonary type is included in WHO 2014 for a tumour which in other organs is termed high small-cell neuroendocrine carcinoma. Neuroendocrine tumours at various sites within the female genital tract often occur in association with other neoplasms and more uncommonly in pure form.

HPV infection and p16INK4A and TP53 expression in rare cancers of the uterine cervix

Cervix cancer remains among most commonly diagnosed cancer in developing countries. Except squamous cell carcinoma and adenocarcinoma, the etiopathology and oncogenic mechanisms of rare cancers remain largely unknown. The study was performed to investigate the value of HPV infection and the expression of p16^INK4A and TP53 in rare primitive cancers of the cervix. We conducted a retrospective study of rare primitive cancers of the cervix. Main clinicopathological features were reported. HPV infection was detected by in situ hybridization. Expression of p16^INK4A and TP53 was analyzed by immunohistochemistry. Overall, seven cases were identified, including basaloid squamous cell carcinoma (BSCC, n = 2), small cell neuroendocrine carcinoma (SCNEC), granulocytic sarcoma without acute myeloid leukemia, leiomyosarcoma, primitive neuroectodermal tumor and botryoid-type embryonic rhabdomyosarcoma. The mean age of patients was 53.7 years. Four cancers were diagnosed at advanced stages. The prognosis was unfavorable and associated with patient death in five cases. HPV types 16/18 were detected in BSCCs and SCNEC. Strong and diffuse p16^INK4A overexpression was described in the nucleus and the cytoplasm of all tumor cells of BSCCs and SCNEC. The remaining cancers exhibited only scattered and focal p16^INK4A staining. Mutated TP53 protein was detected in BSCC (case 1) and GS. Rare cancers of the cervix are aggressive and associated with poor prognosis. In contrast to mesenchymal tumors, BSCCs and SCNEC are etiologically related to high-risk HPV infection and could be identified by block positive p16^INK4A overexpression as common cancers of the cervix. TP53 mutations are not a negligible genetic event in rare cervical cancers.

Exceptional Response to Nivolumab and Stereotactic Body Radiation Therapy (SBRT) in Neuroendocrine Cervical Carcinoma with High Tumor Mutational Burden: Management Considerations from the Center For Personalized Cancer Therapy at UC San Diego Moores Cancer Center

This article reports a patient with a rare metastatic, chemotherapy‐refractory neuroendocrine carcinoma who was treated with stereotactic body radiation therapy (SBRT) combined with anti‐programmed cell death protein 1 antibody. The novel treatment modality of SBRT combined with a checkpoint inhibitor is discussed, as well as the implications of molecular profiling and tumor mutational burden as potential predictors of response.

Neuroendocrine carcinoma of the cervix is an ultra‐rare malignancy with a poor prognosis and limited treatment options. Checkpoint blockade immunotherapy has rapidly developed into an emerging standard of care for several common disease types. Interestingly, in preclinical and retrospective clinical data, radiation therapy has been demonstrated to synergize with checkpoint inhibitors. Here we report a patient with metastatic, chemotherapy‐refractory neuroendocrine carcinoma who presented with partial bowel obstruction due to a large tumor burden. Genomic analysis demonstrated a high number of alterations on liquid biopsy (circulating tumor DNA [ctDNA]), which prompted treatment with stereotactic body radiation therapy (SBRT) combined with anti‐programmed cell death protein 1 antibody. Tissue rebiopsy and comprehensive genomic profiling confirmed high tumor mutational burden and a mismatch repair gene defect. The patient manifested near‐complete systemic resolution of disease, ongoing at 10+ months. We discuss the novel treatment modality of SBRT combined with a checkpoint inhibitor and the implications of molecular profiling and tumor mutational burden as potential predictors of response.

Key Points.

High‐grade, large‐cell neuroendocrine carcinoma of the cervix is an ultra‐rare malignancy that carries a grim prognosis.

Next‐generation sequencing may reveal key mutations in MSH2 genes amongst others. MSH2 mutations target the DNA mismatch repair process and can predispose patients to malignancies with high mutational burdens.

Immunotherapy combined with radiation therapy can elicit a significant response, both within and outside the field of radiation. The latter is termed the “abscopal” effect, perhaps mediated by radiation‐induced cross presentation of tumor antigens resulting in immune activation.

Sequencing of blood‐derived ctDNA showed a high number of alterations, and tissue sequencing confirmed a high tumor mutational burden as a consequence of a mismatch repair gene defect. This observation led to a therapeutic “match” with an anti‐ programmed cell death protein 1 antibody combined with SBRT, resulting in a durable (10+ months), near‐complete remission in a patient with advanced chemotherapy‐refractory disease.

A new marker, insulinoma-associated protein 1 (INSM1), for high-grade neuroendocrine carcinoma of the uterine cervix: Analysis of 37 cases

OBJECTIVE

High-grade neuroendocrine carcinoma of uterine cervix (HGNCUC) has been recognized as a highly malignant tumor. Therapeutic strategy specific to neuroendocrine (NE) tumors needs to be considered, but some cases wouldn't allow simple final diagnoses. Insulinoma-associated protein 1 (INSM1), which is a zinc-finger transcription factor related to NE differentiation, is frequently expressed in NE tumors. We investigated the association between INSM1 and HGNCUC, and the possibility of INSM1 as a useful NE marker.

METHODS

Thirty-seven cases of formalin-fixed and paraffin-embedded HGNCUCs were evaluated immunohistochemically for conventional NE markers and INSM1. We also surveyed polymerase chain reactions and examined the frequency and the genotype of human papillomavirus (HPV) infections.

RESULTS

In HGNCUC, chromogranin A, synaptophysin and neural cell adhesion molecule (NCAM) were expressed in 86%, 86% and 68%, respectively. In addition, INSM1 was detected in 95%. Positivity for INSM1 was clearly evaluated histologically, because the intensity of nuclear staining on positive cells was high and nonspecific reactions were minimal. In uni- and multivariate analyses of prognostic factors on stage I and II surgical cases, the association between INSM1 expression and prognosis was insignificant. We confirmed 72% of 29 examined cases had high risk HPV infections (type 16, 14%; type 18, 86%).

CONCLUSIONS

This study has clarified that INSM1 is closely related to the development of HGNCUC, and a useful new NE marker in conducting its correct and rapid diagnosis.

[Cervical cancer : Update on morphology]

The World Health Organization (WHO) classification from 2014 differentiates between different subtypes of mucinous adenocarcinoma of the uterine cervix. A gastric subtype was recently described that showed no association with high-risk human papillomavirus (HPV) infections, has a poor prognosis, is mainly diagnosed in women of Asian origin and can occur in patients with Peutz-Jeghers syndrome. Although no clear grading system has been recommended in the WHO classification, it is likely that grading of adenocarcinomas of the uterine cervix will partly be based on the different patterns of invasion. Deep stromal infiltration of macroinvasive carcinomas is defined as an infiltration of >66 % of the cervical stroma. In the near future a maximum tumor size of 2 cm could act as a discriminator for planning of less radical surgery. Parameters of the histopathological report that are relevant for the prognostic assessment as well as the choice of adjuvant treatment and function as quality indicators during certification are described. The histological type of an adenocarcinoma alone is of no predictive or prognostic relevance for patients undergoing primary surgical treatment, neoadjuvant chemotherapy, combined chemo-radiotherapy or treatment with angiogenesis inhibitors. Currently, molecular parameters and biomarkers are of no relevance.