Diagnostic issues with cytopathologic interpretation of lung neoplasms displaying high-grade basaloid or neuroendocrine morphology

Basaloid squamous cell carcinoma (BSQCC) and high-grade neuroendocrine carcinomas (HGNEC) including small cell carcinoma (SMCC) and large cell neuroendocrine carcinoma (LCNEC) can be difficult to differentiate on lung cytology. This problem is particularly true in scant specimens where immunoperoxidase stains cannot be adequately performed. Sixty-six cases of BSQCC, LCNEC, and SMCC (22 cases of each) on lung or mediastinal cytology were retrospectively reviewed from the cytopathology archives of two hospitals. Common cytomorphologic characteristics were; hypercellularity, small to intermediate round blue (hyperchromatic) cells, lack of prominent nucleoli, lack of three dimensional architecture, karyorrhexis/necrosis, mitoses, naked nuclei, nuclear crush artifact, and nuclear molding. Distinctive features included: larger cell size with pleomorphism, more cohesive architecture, syncytial aggregation, slightly coarser chromatin texture, rare keratinized malignant cells, and a granular smear background seen more often in BSQCC as opposed to HGNEC. Larger cells with prominent nucleoli and more cytoplasm with focal rosette formation were helpful in distinguishing LCNEC from SMCC and BSQCC. Finally, SMCC displayed uniform small cells with extensive necrosis, and higher mitotic rate. Immunoperoxidase (IPOX) staining using p63, CK5, 6, neuroendocrine markers (chromogranin, synaptophysin and CD56) and TTF-1 were helpful. BSQCC showed p63 expression and was mostly negative for neuroendocrine markers and TTF-1. HGNEC showed immunoreactivity for neuroendocrine markers with variable immunoreactivity for TTF-1. BSQCC, SMCC, and LCNEC share overlapping cytomorphologic features and can be difficult to differentiate on limited cytology specimens. Careful consideration to subtle but definite cytomorphologic clues and attention to selective IPOX stains can lead to a definitive diagnosis.     

Primary Small Cell Neuroendocrine Carcinoma of the Urinary Bladder: A Clinicopathologic,Immunohistochemical, and Ultrastructural Evaluation

Small cell neuroendocrine carcinoma (SCNEC) of the urinary bladder is a rare but aggressive neoplasm that usually exhibits neuroendocrine differentiation. Here, the authors report a case of SCNEC in an 80-year-old man. The patient had gross hematuria and nodular mass involving the wall of the urinary bladder. Total cystectomy was done. The tumor consisted of small, uniform, round, and spindled-shaped cells with chromatin dark nuclei and numerous mitotic figures. The cells were reactive for chromogranin, neuron-specific enolase (diffuse), and keratin (focal). Ultrastructural studies revealed neurosecretory granules and intermediate filaments. The diagnosis of SCNEC with focal high-grade urothelial component was established. No metastasis was found at the time of diagnosis and the patient refused further chemotherapy or radiotherapy. The histogenesis, differential diagnosis, and prognosis of SCNEC of the urinary bladder were discussed.     

Primary large cell neuroendocrine carcinoma of the urinary bladder

Primary large cell neuroendocrine carcinomas (LCNEC) of the urinary bladder are rare. Reported herein is a case of a primary, pure LCNEC occurring in a man. The patient was a 32-year-old man who presented with hematuria of 1 week's duration. On cystoscopic examination, a solitary mass measuring 3 cm in diameter was detected protruding from the anterosuperior wall of the urinary bladder. Two months after the primary transurethral resection, significant regrowth of the remnant mass was noted on CT, and the patient underwent a partial cystectomy. A diagnosis of LCNEC was made based upon histological and immunohistochemical findings. Tumor cells were positive for synaptophysin, chromogranin A, CD56, epithelial membrane antigen, and cytokeratin. Histologically, the tumor penetrated the deep muscle and perivesical fat. In spite of three cycles of chemotherapy, the patient developed multiple metastases in the lung and liver 10 months postoperatively. LCNEC of the urinary bladder are uncommon entities, which have a possible fatal outcome.     

Clinicopathologic and molecular aspects of high-grade neuroendocrine carcinoma of the uterine cervix: emphasis on novel chemotherapeutic strategies

High-grade neuroendocrine carcinomas (HGNEC) of the cervix are rare and carry an extremely poor prognosis. Fortunately, there have been recent advances in our molecular understanding of these carcinomas and some advances offer novel therapeutic options. The vast majority of HGNEC of the cervix are associated with human papillomavirus (HPV) and would be prevented by currently available vaccines. TP53 mutations are variably identified and likely drive a second pathway, one unrelated to high-risk HPV. Most carcinomas express VEGF and some patients have seen durable response to therapy with the addition of a VEGF inhibitor. PIK3CA mutations are among the most common mutations identified and mTOR inhibitors may be considered in these cases. KRAS mutations can be identified; an impressive response to MEK inhibitors has been seen in one case. PD-L1 positivity is frequently seen and complete responses to PD-1/PD-L1 inhibitors have been reported. These molecular advances offer numerous approaches to targeted personalized therapy.     

Expression of L-type amino acid transporter 1 (LAT1) in neuroendocrine tumors of the lung

Amino acid transport systems play an important role in cellular proliferation. L-type amino acid transporter 1 (LAT1) has been associated with tumor growth, and is highly expressed in the established tumor cell lines and primary human neoplasms. In this study, we investigated the expression of LAT1 to evaluate the malignant potential and prognostic significance in neuroendocrine (NE) tumors of the lung. Twenty-one surgically resected, large cell neuroendocrine carcinomas (LCNEC), 13 small cell lung cancers (SCLC), five atypical carcinoids (AC), and 10 typical carcinoids (TC) were enrolled in the study. LAT1 expression and Ki-67 labeling index of the NE tumors were analyzed by immunohistochemical staining. LAT1 was overexpressed in 52.4% of the LCNEC, in 46.2% of the SCLC, and in 25% of the AC. LAT1 expression in LCNEC was significantly associated with lymph node metastasis and poor outcome. Moreover, a significant correlation was found between LAT1 expression and Ki-67 in both LCNEC and SCLC. Expression of LAT1 tended to increase from low-grade to high-grade NE tumors. The present results suggest that LAT1 may play a significant role in cellular proliferation, lymph node metastasis, and poor outcome in patients with NE tumors of the lung.     

High-grade neuroendocrine carcinoma of the lung: Comparative clinicopathological study of large cell neuroendocrine carcinoma and small cell lung carcinoma

Large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC) are high-grade neuroendocrine carcinomas. In order to clarify the similarities and differences between these cancers, 22 cases each of LCNEC and SCLC were collected and a comparative pathological study was carried out. First, their clinicopathological characteristics were confirmed, which were very similar to those previously reported. The 5 year survival rate of LCNEC and SCLC patients was 38.3% and 29.7%, respectively. The morphological characteristics of LCNEC and SCLC were then reviewed with regard to the morphology previously used to differentiate these cancers. As a result, many morphological indicators, such as tumor cell size, nuclear/cytoplasmic ratio, nuclear molding, rosette formation, prominent nucleoli and karyolysis were confirmed to be significant indicators for distinguishing LCNEC from SCLC. On comparative immunohistochemistry, LCNEC had significantly high staining scores for the expression of keratin 7 and 18, E- and P-cadherins, β-catenin, villin 1, retinoblastoma protein (pRB), c-met and α-enolase. These results might reflect the differentiation or deviation of LCNEC toward an epithelial nature irrespective of neuroendocrine tumor lineage. In conclusion, the present comparative study of LCNEC and SCLC defined the similarities and differences between these cancers, and showed the biologically and clinicopathologically overlapping spectrum of the tumor lineage.     

Large cell neuroendocrine carcinoma of the urinary bladder with lymphoepithelioma-like features

The group of undifferentiated carcinomas of the urinary bladder encompasses small cell undifferentiated carcinoma, giant cell carcinoma, lymphoepithelioma-like carcinoma (LELC), and large cell neuroendocrine carcinoma (LCNEC). These tumors are either pure or can be associated with other components, such as transitional cell carcinoma, squamous cell carcinoma, and adenocarcinoma. We report a case of LCNEC of the urinary bladder in a 54-year-old woman. Histologically, the tumor showed features of LELC; immunohistochemically, the tumor cells reacted to chromogranin A, NSE, and synaptophysin. In addition to these neuroendocrine markers, tumor cells were positive for cytokeratin CAM 5.2 and AE1/AE3, and there was focal positivity for vimentin. In situ hybridization for the detection of Epstein-Barr virus was negative. Despite radical cystourethrectomy and six courses of chemotherapy, the patient developed metastases invading the left inguinal lymph nodes 11 months postoperatively. Currently, 16 months postoperatively, the patient has developed metastases spreading into the lymph nodes of the right ischiorectal fossa; therefore, she is receiving a new cyclus of chemotherapy. There are only three previously reported cases of LCNEC of the urinary bladder, and the significance of neuroendocrine differentiation in non-small cell carcinomas at this location remains to be established. However, LELC appears to be a separate clinicopathological entity with sensitivity to chemotherapy and a relatively favorable prognosis. The differentiation between LELC and LCNEC with prominent inflammatory reaction could be of therapeutic relevance. However, in our case, this was possible using immunohistochemistry only.     

E-cadherin-beta-catenin adhesion complex in neuroendocrine tumors of the lung: a suggested role upon local invasion and metastasis

Dysfunction or loss of the intercellular adhesion complex E-cadherin-beta-catenin is frequent in non-small cell lung carcinomas in which E-cadherin and beta-catenin loss has been considered to be a molecular marker of tumor progression and poor prognosis. With an aim of evaluating the expression of the E-cadherin-beta-catenin complex and its prognostic role in neuroendocrine tumors (NET) of the lung, immunohistochemical analysis was performed in 102 NET, including 16 low-grade typical carcinoids, 8 intermediate-grade atypical carcinoids, 37 large-cell neuroendocrine carcinomas (LCNEC), and 41 small-cell lung carcinomas, both high-grade tumors. Impaired E-cadherin expression (loss or cytoplasmic delocalization) was observed in 80 (78%) of 102 samples, and impaired beta-catenin expression was noted in 74 (72%) of 102 cases. The impaired expression of E-cadherin and beta-catenin was observed with a higher frequency in high-grade tumors (87% and 83%, respectively) than in carcinoids (50% and 37%, respectively; P < 0.0001). Impaired expression of the E-cadherin and beta-catenin molecules also correlated with lymph node metastasis (P = 0.0001 and P = 0.0005, respectively) and with advanced stage disease (P < 0.0001 for both factors). Moreover, impaired E-cadherin expression directly correlated with an extensive disease in carcinoids and in LCNEC (P = 0.02 and P = 0.04, respectively) and with node metastasis in LCNEC (P = 0.01). Levels of E-cadherin and beta-catenin were correlated with each other, consistent with an internal regulatory loop. Our results indicate that down-regulation of the E-cadherin-beta-catenin complex plays a role in NET progression.     

Biological and clinical significance of NAC1 expression in cervical carcinomas: a comparative study between squamous cell carcinomas and adenocarcinomas/adenosquamous carcinomas

This study examined the biological and clinical significance of NAC1 (nucleus accumbens associated 1) expression in both cervical squamous cell carcinomas and adenocarcinomas/adenosquamous carcinomas. Using immunohistochemistry, the frequency of positive NAC1 expression in adenocarcinomas/adenosquamous carcinomas (31.0%; 18/58) was significantly higher than that in squamous cell carcinomas (16.2%; 12/74) (P = .043). NAC1 gene amplification was identified by fluorescence in situ hybridization in 5 (7.2%) of 69 squamous cell carcinomas. NAC1 amplification was not identified in the adenocarcinomas (0%; 0/58). Positive NAC1 expression was significantly correlated with shorter overall survival in squamous cell carcinomas (P < .0001). A multivariate analysis showed that positive NAC1 expression in squamous cell carcinomas was an independent prognostic factor for overall survival after standard radiotherapy (P = .0003). In contrast to squamous cell carcinomas, positive NAC1 expression did not correlate with shorter overall survival in adenocarcinomas/adenosquamous carcinomas (P = .317). Profound growth inhibition, increased apoptosis, decreased cell proliferation, and decreased cell migration and invasion were observed in silencing RNA-treated cancer cells with NAC1 overexpression compared with cancer cells without NAC1 expression. NAC1 overexpression stimulated proliferation, migration, and invasion in the cervical cancer cell lines TCS and Hela P3, which normally lack NAC1 expression. These findings indicate that NAC1 overexpression is critical to the growth and survival of cervical carcinomas irrespective of histologic type. Furthermore, they suggest that NAC1 silencing RNA-induced phenotypes depend on the expression status of the targeted cell line. Therefore, cervical carcinoma patients with NAC1 expression may benefit from a targeted therapy irrespective of histologic type.     

hASH1 expression is closely correlated with endocrine phenotype and differentiation extent in pulmonary neuroendocrine tumors.

The human homolog 1 of the Drosophila neurogenic achaete-scute genes, hASH1, is specifically expressed in fetal pulmonary neuroendocrine cells and in some neuroendocrine tumor cell lines. However, no data have been gathered regarding its in vivo expression in tumors. hASH1 mRNA expression was investigated by in situ hybridization in 238 surgically resected lung carcinomas, and the correlations between hASH1 expression status and immunostaining results of neuroendocrine markers chromogranin A, neural cell adhesion molecule, gastrin-releasing peptide and calcitonin, and clinical outcome were analyzed. hASH1 expression was detected in 2/20 (10%) adenocarcinomas, 4/30 (13.3%) typical carcinoids, 11/13 (84.6%) atypical carcinoids, 38/67 (56.7%) large-cell neuroendocrine carcinomas and 56/78 (71.8%) small-cell carcinomas, respectively, but not in any squamous cell carcinoma (0/21) or large-cell carcinoma (0/9). The 2 hASH1+ adenocarcinomas also expressed multiple neuroendocrine markers. Thus, hASH1 expression was restricted to lung cancers with neuroendocrine phenotypes. However, not all neuroendocrine tumors expressed hASH1. Within the entities of large-cell neuroendocrine carcinoma and small-cell carcinoma, hASH1 expression correlated very closely with chromogranin A, gastrin-releasing peptide and calcitonin expression (P<0.0001, r=0.852), but was not related to neural cell adhesion molecule expression (P=0.8892), suggesting that hASH1 expression, at least in lung cancer, is associated with endocrine phenotype expression other than 'neuroendocrine differentiation' in a broad sense. The fact that hASH1 was virtually absent in almost fully differentiated typical carcinoids, but was expressed in most, if not all, less differentiated atypical carcinoids as well as large-cell neuroendocrine carcinomas and small-cell carcinomas, suggests that hASH1 expression in lung cancer imitates its early and transient expression in fetal development, and that hASH1 is instrumental in the establishment, but not in the maintenance, of a cellular endocrine phenotype. Finally, hASH1 expression correlated with a significantly shortened survival in small-cell carcinoma patients (P=0.041).     

Characteristics of loss of heterozygosity in large cell neuroendocrine carcinomas of the lung and small cell lung carcinomas

Large cell neuroendocrine carcinoma (LCNEC) of the lung is a new entity. Besides morphological characteristics, its molecular biological features have been investigated by many researchers and compared to those of other neuroendocrine carcinomas, small cell lung carcinoma (SCLC) and carcinoid tumor (CT). However, there are few reports that show the significantly different genetic characteristics between them. The purpose of the present paper was to study the frequency of loss of heterozygosity (LOH) at chromosome 3p (3p14.2) in 38 neuroendocrine carcinomas of the lung (13 LCNEC, 11 SCLC and 14 CT) and 10 large cell carcinomas (LCC). The frequencies of LOH at 3p14.2 were 69.2% in LCNEC, 81.8% in SCLC, 50.0% in LCC and 7.14% in CT. Those at 22q13.3 were 30.8% in LCNEC, 72.7% in SCLC, 45.5% in LCC and 7.14% in CT. In particular, the frequency of SCLC with LOH at both 3p14.2 and 22q13.3 (63.6%) was significantly higher than that of LCNEC (15.4%). LCNEC and SCLC had different characteristics of LOH patterns at 3p14.2 and 22q13.3. The combined analysis of the LOH at 3p14.2 and 22q13.3 is thought to be useful for differential diagnosis between LCNEC and SCLC.     

Tumor genetics and survival of thymic neuroendocrine neoplasms: A multi‐institutional clinicopathologic study

Thymic neuroendocrine tumors (TNET) are rare primary epithelial neoplasms of the thymus. This study aimed to determine clinically relevant parameters for their classification and for therapeutic decisions. We performed a comprehensive histological, clinical, and genetic study of 73 TNET cases (13 thymic typical carcinoids [TTC], 40 thymic atypical carcinoids [TAC], and 20 high‐grade neuroendocrine carcinomas [HGNEC] of the thymus), contributed by multiple institutions. The mean number of chromosomal imbalances per tumor was 0.8 in TTC (31% aberrant cases) versus 1.1 in TAC (44% aberrant cases) versus 4.7 in HGNEC (75% aberrant cases). Gains of 8q24 (MYC gene locus) were the most frequent alteration and one of the overlapping features between carcinoids and HGNEC. The 5‐year survival rates for TTC, TAC, and HGNEC were 100, 60, and 30%. The 10‐year survival rates for TTC and TAC were 50 and 30% (P = 0.002). Predictive mitotic cut‐off values for TTC versus TAC were 2.5 per 10 high‐power fields (HPF; indicating a higher death rate, P = 0.062) and 15 per 10 HPF (indicating higher risk of recurrence, P = 0.036) for separating HGNEC from TAC. We conclude that the current histopathologic classifications of TNET reflect tumor biology and provide important information for therapeutic management. © 2014 Wiley Periodicals, Inc.     

Caveolins as tumour markers in lung cancer detected by combined use of cDNA and tissue microarrays

To identify new potential diagnostic markers for lung cancer, the expression profiles of 37 lung tumours were analysed using cDNA arrays. Seven samples were from small-cell lung cancer (SCLC), two from large-cell neuroendocrine tumours (LCNEC), and 28 from other non-small-cell lung cancers (mainly squamous cell cancer and adenocarcinoma). Principal component analysis and the permutation test were used to detect differences in the gene expression profiles and a set of genes was found that distinguished high-grade neuroendocrine carcinomas (SCLC and LCNEC) from other lung cancers. In addition, several genes, such as caveolin-1 (CAV1) and caveolin-2 (CAV2), were constantly deregulated in all types of tumour sample, compared with normal tissue. The expression of these two genes was investigated further at the protein level on a tissue microarray containing tumours from 161 patients and normal tissues. Immunostaining for CAV1 was negative in 48% of tumours, whereas 28% of the tumours did not express CAV2. Lack of CAV1 protein expression was not caused by methylation or mutation. In stage I adenocarcinomas, CAV2 protein expression correlated with shorter survival. In conclusion, the present study was able to identify genes that have not previously been implicated in lung cancer by the combined use of two different array techniques. Some of these genes may provide novel diagnostic markers for lung cancer.     

LKB1 protein expression in neuroendocrine tumors of the lung

During a recent investigation of LKB1 gene abnormality in lung lesions, strong expression of LKB1 protein in normal neuroendocrine (NE) cells of the bronchial epithelium was found. Because LKB1 functions as a tumor suppressor gene, the question of whether alteration of LKB1 expression is related to the development of pulmonary NE tumors of various grades was investigated. LKB1 immunohistochemistry was examined in a total of 68 primary pulmonary NE tumors consisting of 30 specimens of small cell lung carcinoma (SCLC), 23 large cell neuroendocrine carcinomas (LCNEC), two atypical carcinoids, and 13 typical carcinoids. Loss or low expression (<20% immunoreactive cells) of LKB1 protein expression was more frequently observed in high-grade NE tumors (SCLC and LCNEC; 45/53, 84.9%) than in typical and atypical carcinoids (3/15; 20%). The difference in LKB1 immunoreactivity between the high-grade NE tumors and the carcinoid group was statistically significant ( P  < 0.0001). In conclusion, marked reduction of LKB1 expression in high-grade NE tumors of the lung suggests a possible role of LKB1 inactivation in its tumorigenesis. Although a few previous studies indicated rare genetic alterations of LKB1 in SCLC, further studies including analysis of other NE tumors and focusing on epigenetic abnormalities of LKB1 gene are warranted.     

High-grade neuroendocrine carcinomas of the lung express K homology domain containing protein overexpressed in cancer but carcinoid tumors do not

K homology domain containing protein overexpressed in cancer (KOC) is a member of the insulin-like growth factor (IGF) messenger RNA-binding protein family and is expressed during embryogenesis and in certain malignancies. KOC, known as L523S and IGF messenger RNA-binding protein 3, was shown to be frequently expressed in high-grade neuroendocrine carcinomas of the lung in our immunohistochemical studies using a monoclonal antibody against human KOC. Specifically, all 10 small cell lung carcinomas (SCLCs) exhibited strong cytoplasmic staining, 9 with diffuse positivity and 1 with focal positivity. Among 14 large cell neuroendocrine carcinomas (LCNECs), 9 exhibited strong and diffuse cytoplasmic staining, and 5 cases showed focal immunoreactivity. In contrast, no KOC was detected in 21 typical and atypical carcinoids, except for one atypical carcinoid with oncocytic cells showing weak cytoplasmic staining. Although SCLCs exhibited a strong and diffuse staining pattern more frequently (90%) than LCNECs (64%), the difference did not reach statistical significance (P = .3408). Interestingly, our immunohistochemical studies demonstrated that IGF-II, reportedly regulated by KOC, was comparably expressed in SCLC, LCNEC, and typical and atypical carcinoids, irrespective of KOC expression status of the tumors. These results support the formulation that KOC may play an important role in the regulation of biologic behavior of high-grade neuroendocrine carcinomas. In addition, detection of KOC expression may be diagnostically useful in distinguishing high-grade neuroendocrine carcinomas from carcinoid tumors. Our findings of equivalent IGF-II expression in KOC-positive SCLC and LCNEC and KOC-negative carcinoid tumors suggest different regulatory mechanisms involved in the control of IGF-II expression in these tumors.     

A subset of high-grade pulmonary neuroendocrine carcinomas shows up-regulation of matrix metalloproteinase-7 associated with nuclear β-catenin immunoreactivity,independent of EGFR and HER-2 gene amplification or expression

Nuclear translocation of β-catenin has been correlated with epidermal growth factor receptor (EGFR) overexpression/activation in nonsmall cell lung cancer. Less is known on β-catenin transactivation in high-grade pulmonary neuroendocrine tumors and on the status of β-catenin activating EGFR and human epidermal growth factor receptor 2 (HER-2) or β-catenin target genes cyclin D1 and matrix metalloproteinase-7 (MMP-7). β-catenin immunoreactivity was evaluated in 51 large-cell neuroendocrine carcinomas (LCNEC) and 45 small-cell lung carcinomas (SCLC). Nineteen cases were assessed for β-catenin gene exon 3 mutations, expression of MMP-7, and expression/gene amplification of EGFR, HER-2, and cyclin D1. β-catenin was expressed in all 96 high-grade neuroendocrine tumors, the vast majority (94%) showing >50% immunopositive cells. A disarrayed immunoreactivity, however, was commonly encountered consisting in variably altered membrane-associated patterns of staining along with progressive accumulation of cytoplasmic immunoreactivity. In LCNEC, but not in SCLC, the disarrayed patterns correlated with EGFR and HER-2 protein expression. β-catenin nuclear accumulation was found in nine tumors, including seven LCNEC and two SCLC, and was always associated with disarrayed immunoreactivity and increased MMP-7, but not cyclin D1 expression. These cases, however, did not show β-catenin gene mutations or EGFR and HER-2 gene amplification or expression. No association was found between nuclear β-catenin and any clinicopathological variable including patients' survival. The subcellular compartmentalization of β-catenin is profoundly altered in high-grade pulmonary neuroendocrine tumors. A minor subset of these tumors shows β-catenin nuclear accumulation in association with increased expression of MMP-7, but not of cyclin D1, independent of EGFR and HER-2 gene amplification or expression. The authors have no significant financial or other relationship with the manufacturers of any commercial products or commercial services presented in this paper     

Spectrum of neuroendocrine carcinomas of the uterine cervix,including histopathologic features,terminology, immunohistochemical profile,and clinical outcomes in a series of 50 cases from a single institution in India

Neuroendocrine carcinomas of the cervix are uncommon, characterized by a histomorphological spectrum and, mostly, an aggressive clinical course. There are only few substantial studies on such cases documented from our country, where cervical cancer is the second most common cancer affecting women. Herein, we present a spectrum of 50 cervical neuroendocrine carcinomas, including histopathologic features, terminology, immunohistochemical (IHC) profile, and clinical outcomes, wherever available. Fifty tumors occurred in women, with their age ranging from 23 to 69 years (mean, 48.6 years; median, 46.5 years). Stagewise, among 25 cases, most cases (6, or 24%) presented with stage IB. Average tumor size was 4.7 cm. On histopathologic review, 26 tumors (52%) were classified as small cell carcinoma (SMCA); 14 (28%), as large cell neuroendocrine carcinomas (LCNECs); 4 (8%), as SMCA + LCNECs; and 6, as mixed carcinomas, including 3 tumors (6%) with SMCA and squamous cell carcinoma (SCC), 2 tumors (4%) with LCNEC and adenocarcinoma, and a single tumor (2%) with LCNEC and squamous cell carcinoma. On IHC performed in 41 tumors (82%), 36 tumors (87.8%) were positive for at least a single neuroendocrine marker, and 22 (53.6%) expressed 2 neuroendocrine markers. Synaptophysin was positive in 22 (59.4%) of 37 tumors; chromogranin, in 27 (72.9%) of 37; CD56, in 8 (100%) of 8; and neuron-specific enolase in 7 (87.5%) of 8 tumors. Treatment wise, among 30 patients (60%), 6 (20%) underwent surgery, including Wertheim hysterectomy (5) and simple hysterectomy (1); 8 (26.6%) underwent surgery with adjuvant treatment, and 10 patients (33.3%) were offered chemotherapy and/or radiotherapy. On follow-up (27 patients, or 54%) over 1 to 144 months, 16 patients (59.2%) were alive with disease over median duration of 9 months, and 7 (25.9%) were free of disease over median duration of 26.5 months. There were 5 recorded deaths. Thirteen tumors (48.1%) metastasized, most commonly to liver. In cases with early stage disease and adjuvant treatment, including radiotherapy, LCNEC histology fared well. This study forms the largest documented series on cervical neuroendocrine carcinomas from our country, testifying the current histopathologic classification system. Although SMCAs can be recognized on morphology, LCNECs need to be correctly identified because these can be misdiagnosed in the absence of neuroendocrine markers. Synaptophysin, chromogranin, and CD56 are optimal IHC markers. Small cell carcinomas, pure or mixed, are relatively more aggressive. All these tumors are best treated with multimodal therapy. Early stage disease treated with radical surgery and adjuvant treatment seems to increase survival. Despite aggressive treatment, prognosis is dismal.