Reliability of commercially available immunocytochemical markers for identification of neuroendocrine differentiation in bronchoscopic biopsies of bronchial carcinoma

Recurrent Mixed Neuroendocrine-Non-Neuroendocrine Neoplasm in the Gallbladder: A Case Report

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN) of the gallbladder are rare with no established therapeutic strategies. We report a case of recurrent gallbladder MiNEN from a population with a low incidence of gallbladder carcinomas, a review of the current therapeutic options, and recent updates on the nomenclature proposed by the World Health Organization in 2017.

Squamoid cyst of pancreatic ducts: a case series describing novel immunohistochemistry, cytology, and quantitative cyst fluid chemistry

Squamoid cyst of pancreatic ducts (SCPD) is a benign pancreatic cyst often misdiagnosed preoperatively as a mucinous cyst. The histopathologic features are well described but the cytology and quantitative fluid chemistry profiles from fine-needle aspiration have not been reported. This case series discusses the cytology and cyst fluid chemistry profiles in 2 SCPDs and describes morphologic and immunohistochemical features that have not been previously reported. Fine-needle aspiration of 2 SCPDs yielded acellular debris lacking mucin or exfoliated squamous cells. Two cysts had elevated fluid carcinoembryonic antigen (CEA) and amylase levels. Positive immunohistochemical staining included cytokeratin 5/6, pCEA, synaptophysin, and chromogranin (both focal). MUC2 and MUC5AC showed negativity in all cases, while PAX8 showed negative nuclear staining. An accurate preoperative diagnosis of SCPD is potentially difficult in the setting of elevated fluid CEA levels, and acellular cytology as a mucinous cyst cannot be confidently excluded.

Neuroendocrine tumours--challenges in the diagnosis and classification of pulmonary neuroendocrine tumours

Pulmonary neuroendocrine (NE) proliferations are a diverse group of disorders which share distinct cytological, architectural and biosynthetic features. Tumours composed of NE cells are dispersed among different tumour categories in the WHO classification of tumours and as such do not conform to a singular group with regards to treatment and prognosis. This is reflected by the highly variable behaviour of NE proliferations, ranging from asymptomatic, for instance in diffuse idiopathic pulmonary NE cell hyperplasia and tumourlets, to highly malignant cancers such as small cell lung cancer and large cell NE carcinoma. In this review NE proliferations are described as distinct entities ranging from low grade lesions to high grade cancers. The differential diagnoses are considered with each of the entries. Finally, mention is made of tumours which may show some NE features.

Immunohistochemical studies of pulmonary large cell neuroendocrine carcinoma: a possible association between staining patterns with neuroendocrine markers and tumor response to chemotherapy

OBJECTIVE

Pulmonary large cell neuroendocrine carcinoma is a rare high-grade malignant tumor. Because large cell neuroendocrine carcinoma is rare, the optimal treatment, including perioperative chemotherapy, has not been defined. We retrospectively analyzed the correlation among the effectiveness of perioperative chemotherapy in treating large cell neuroendocrine carcinoma, pathologic stage, and immunoreactivity to neuroendocrine markers.

METHODS

A total of 63 patients with pulmonary large cell neuroendocrine carcinoma undergoing surgical resection from 2001 to 2009 were included. The resected tumors were immunohistochemically stained with the 3 neuroendocrine markers synaptophysin, chromogranin A, and neural cell adhesion molecule. We categorized patients who were positive for all 3 markers as the triple-positive group and those who were negative for 1 or 2 markers as the non-triple-positive group.

RESULTS

Perioperative chemotherapy resulted in better overall survival than surgery alone (P = .042). Multivariate analysis of survival revealed that perioperative chemotherapy was a significant independent prognostic factor (hazard ratio, 0.323; 95% confidence interval, 0.112-0.934; P = .0371). Among the patients who received perioperative chemotherapy, the non-triple-positive group had a significantly greater 5-year survival rate than the triple-positive group (P = .0216). Moreover, among the non-triple-positive group, a significantly greater 5-year survival rate was observed for the patients who underwent surgery with chemotherapy than for those who underwent surgery without chemotherapy (P = .0081). In contrast, no difference was found in 5-year survival between patients with chemotherapy and those without chemotherapy when the tumors were triple positive.

CONCLUSIONS

Our results suggest that perioperative chemotherapy might benefit the survival of patients with pulmonary large cell neuroendocrine carcinoma, in particular when the tumors are not immunoreactive to all 3 neuroendocrine markers.

Neuroendocrine differentiation as an indicator of chemosensitivity and prognosis in nonsmall cell lung cancer

CONTEXT

Nonsmall cell lung cancers with neuroendocrine differentiation (NSCLC-ND) may demonstrate biologic behavior intermediate between NSCLC and small cell lung cancer (SCLC) with impact on prognosis.

METHODS

We analyzed 116 consecutive patients with Stage III and IV NSCLC who were diagnosed and treated between 2001 and 2006. Using immuno-histochemical staining for neuron-specific enolase (NSE), chromogranin A (ChrA), and synaptophysin (Syn), 29 (25%) NSCLC-ND were identified.

RESULTS

Expression of NSE was present in 22.4%, ChrA in 15.5% and Syn in 14.8% of patients with NSCLC. Therapeutic response was significantly better in the NSCLC-ND group and specimens with > 30% neuroendocrine (NE)-differentiated tumor cells showed favourable therapeutic response (P < 0.05). Multivariate binary logistic regression showed that percentage of NE positive tumor cells was a significant independent prognostic factor associated with a favourable outcome. Receiver operating characteristic (ROC) curves and areas under ROC curves confirmed that percentage of NE-differentiated tumor cells could be useful prediction factor of therapeutic response. Moreover, according to percentage of NE-differentiated tumor cells, optimal cutoffs and related sensitivities and specificities were determined for each markers.

CONCLUSION

Advanced-stage NSCLC with NE tumor cells are clinically less aggressive tumors. Percentage of NE-differentiated tumor cells identifies patients with favourable therapy response to paclitaxel-cisplatin.

Cytologic and immunohistochemical characterization of a lung carcinoid in a dog

An 11-year-old neutered male Yorkshire Terrier was presented to the Haemaru Referral Animal Hospital with a history of unresponsive tracheal collapse and an incidental finding of a lung nodule in the left caudal lung lobe on radiography. Thorough physical examination and imaging studies revealed no other masses. Cytologic examination of C-arm mobile fluoroscopy-guided fine-needle aspirates revealed numerous free nuclei and a low number of small round cells with moderate to abundant pale basophilic cytoplasm. Some cells contained indistinct basophilic granules in their cytoplasm, and extracellular pink material was noted. A caudal lung lobectomy was performed, and histologic evaluation of the mass revealed round to polygonal cells with abundant eosinophilic granular cytoplasm and round nuclei with mild anisokaryosis and 0-3 mitotic figures per high-power field. Cells were arranged in packets separated by fine fibrovascular stroma, suggestive of a pulmonary neuroendocrine neoplasm, specifically a carcinoma/carcinoid. The cells were immunoreactive for chromogranin A and neuron-specific enolase, and negative for cytokeratin, synaptophysin, calcitonin, thyroglobulin, parathyroid hormone, CD79a, light lambda, and vimentin. With these findings the tumor was diagnosed as a primary lung carcinoid. Eleven months after resection, there was no evidence of tumor regrowth or metastasis. The absence of necrosis, few mitotic figures, minimal pleomorphism, and benign behavior of this tumor resembled those of a typical carcinoid in humans.

Expression of neuroendocrine markers in non-small cell lung cancer

Neuroendocrine (NE) differentiation is reported in some cases of non-small cell lung cancer (NSCLC). The aim of this study was to evaluate the expression of NE markers in NSCLC using novel sensitive methods. 20 cases of NSCLC were examined using immunohistochemical (IHC) and immunoelectron microscopy (IEM) methods. In addition, circulating levels of the NE markers chromogranin A (CgA) and neuron-specific enolase (NSE) were measured. Using conventional IHC methods, two tumours (10%) showed immunoreactivity for synaptophysin (SYN), one (5%) for Cg and four (20%) for neural cell adhesion molecule (NCAM). Adding the tyramide signal amplification (TSA) technique, the number of immunoreactive tumours for both SYN and CgA increased to five (25%). No increased immunoreactivity was achieved for NCAM. Nine tumours (45%) were immunoreactive for SYN, CgA or NCAM. Using IEM, one of five representative samples that revealed IHC reactivity for CgA showed immunogold labelling of CgA in cytoplasmic vesicles. Elevated levels of circulating CgA or NSE did not correlate with positive IHC findings. In conclusion, using sensitive IHC methods NE differentiation was seen in a greater proportion of NSCLC than previously reported. Sensitive methods may improve our understanding of the tumour biology and represent an important diagnostic tool for future therapeutic modalities.

Nonsmall cell lung carcinoma with neuroendocrine differentiation--an entity of no clinical or prognostic significance

The existence of non-small cell lung carcinoma with neuroendocrine differentiation as a distinct entity and its relevance for prognostic and treatment purposes is controversial. This study assesses the frequency and biologic and prognostic significance of neuroendocrine (NE) expression of synaptophysin (SNP), chromogranin (Ch), and neural cell adhesion molecule (N-CAM) using tissue microarray (TMA) and immunohistochemistry. Six hundred nine nonsmall cell lung carcinomas (NSCLCs) were reviewed for subclassification. TMA blocks were made using duplicate 0.6-mm-diameter tissue cores and slides stained with SNP, Ch, and N-CAM. Immunoreactivity was considered if 1% or more of tumor cells were positive. Hematoxylin and eosin-stained sections were subclassified as: 243 adenocarcinoma (ACA), 272 squamous cell carcinoma (SCC), 35 large cell carcinoma, 32 non-small cell carcinoma NOS, and 6 other (carcinosarcoma, giant cell carcinoma). Positivity for either marker was identified in 13.6% of NSCLC (76/558). NSCLC showed reactivity for Ch in 0.4% of cases (2/524), for SNP in 7.5% of cases (39/521) and for N-CAM in 8.6% of cases (44/511), whereas only 0.2% of cases (1/517) showed coexpression of SNP and Ch and none of all 3 markers. The assessment of NE differentiation in NSCLC is unnecessary and expensive and is of no clinical or prognostic significance. SNP or N-CAM stains a small minority of NSCLC, whereas Ch immunoreactivity is less common. Positivity for any 2 NE markers is rare. SNP is more likely to be expressed in adenocarcinoma (P=0.01) and N-CAM in squamous-cell carcinoma (P=0.008). Otherwise there was no correlation between immunoreactivity and tumor morphology. Disease specific and overall survival is not influenced by NE differentiation and therefore non-small cell lung carcinoma with neuroendocrine differentiation should not be a subclass distinct from the other NSCLC.

Secretagogin, a novel neuroendocrine marker, has a distinct expression pattern from chromogranin A

Preliminary data suggest that secretagogin (SCGN), a calcium-binding protein identified from our previous proteomics study of colorectal cancers, is a potentially useful neuroendocrine marker. In this study, we further analyzed SCGN expression in normal and tumor tissues from various organ sites compared with three other conventional neuroendocrine markers [chromogranin A (CgA), neuron specific enolase, and synaptophysin]. We found strong SCGN staining in most normal neuroendocrine tissues except in the adrenal cortex. SCGN expression was identified in 140 out of 213 neuroendocrine tumors and 12 conventional carcinomas with neuroendocrine differentiation. In a subset of neuroendocrine tumors, such as gastric neuroendocrine cancers and typical carcinoid tumors of rectum and ovary, SCGN showed strong staining while CgA expression was often negative. It is intriguing to note that SCGN staining was positive in 26 out of 31 small cell lung cancers, more frequently than the other three markers. We conclude that SCGN is a novel neuroendocrine marker that may be useful in routine surgical pathology practice.

Neuroendocrine-like differentiation of non-small cell lung carcinoma cells: regulation by cAMP and the interaction of mac25/IGFBP-rP1 and 25.1

The need to develop more effective therapies for lung cancer has led to investigations in understanding the molecular mechanisms of the differentiation process, in particular neuroendocrine (NE) differentiation. Recent studies have demonstrated that NE differentiation in non-small cell lung carcinoma (NSCLC) is not uncommon. Those NSCLCs with NE differentiation are considered a form of in transition NE carcinoma and show a more aggressive clinical course compared with NSCLC without NE differentiation. 25.1, a novel protein interacting with mac25/insulin-like growth factor-binding protein-related protein 1 (mac25/IGFBP-rP1), induced NE-like differentiation when collectively overexpressed in M12 prostate cancer cells. We have examined mac25/IGFBP-rP1 and 25.1 as potential molecular regulators in vitro of the NE-differentiation process in lung cancer. In a panel of SCLC and NSCLC cell lines, mac25/IGFBP-rP1 and 25.1 were expressed at higher levels in SCLC. An increase and sustained activation of adenosine 3',5'-cyclic monophosphate (cAMP) levels induced NE-like differentiation in NSCLC cell lines, and a concomitant increase in the expression of mac25/IGFBP-rP1 and 25.1 was observed during the cAMP-regulated differentiation of NCI-H157 cells, suggesting the involvement of these proteins. Furthermore, the collective overexpression of mac25/IGFBP-rP1 and 25.1 in NSCLC cells induced NE-like differentiation as early as 6 h postinfection. The present data suggest that mac25/IGFBP-rP1 and 25.1 may play a functional role in the NE differentiation of NSCLC cell lines and may provide a novel therapeutic target for treating lung cancers, in particular NSCLC with NE differentiation.

Neuroendocrine differentiation in non-small cell lung cancer and its relation to prognosis and therapy

AIMS

Histopathologists report the presence of neuroendocrine (NE) differentiation in non-small cell lung carcinoma (NSCLC) in up to a third of cases and are often questioned about its clinical relevance. The conclusions of previous studies have been inconsistent. This paper aims to provide an answer by examining a large series together with a comprehensive critique of the literature.

METHODS AND RESULTS

Four hundred and thirty-nine cases of NSCLC were examined, immunohistochemically, using antibodies to chromogranin A (CGA), synaptophysin (SYN) and CD56/neural cell adhesion molecule (NCAM). Three hundred and forty-one cases had been treated with surgical resection and the remainder with chemotherapy. The results were compared with clinical outcome. Thity-six percent of cases had positive staining for at least one NE marker. CGA was positive in 5.5% of cases, SYN in 16.5% and NCAM in 28%. There was no association between the presence of NE markers and survival in either the surgically treated group or the chemotherapy-treated group. There was also no association between NE markers and response to chemotherapy in the latter group.

CONCLUSIONS

The presence of immunohistochemically detected NE differentiation in NSCLC is not of prognostic significance.

Typical and Atypical Pulmonary Carcinoid Tumor Overdiagnosed as Small-Cell Carcinoma on Biopsy Specimens

Seven patients with typical or atypical pulmonary carcinoid tumors overdiagnosed as small-cell carcinoma on bronchoscopic biopsies are described. Bronchial biopsies from 9 consecutive small-cell lung carcinoma patients were used as control group for histologic and immunohistochemical studies (cytokeratins, chromogranin A, synaptophysin, Ki-67 [MIB-1], and TTF-1). The carcinoid tumors presented as either central or peripheral lesions composed of tumor cells with granular, sometimes coarse chromatin pattern, high levels of chromogranin A/synaptophysin immunoreactivity, and low (<20%) Ki-67 (MIB-1) labeling index. The tumor stroma contained thin-walled blood vessels. Small-cell carcinomas always showed central tumor location, finely dispersed nuclear chromatin, lower levels of chromogranin A/synaptophysin, and high (>50%) Ki-67 (MIB-1) labeling index. The stroma contained thick-walled blood vessels with glomeruloid configuration. Judging from this study, overdiagnosis of carcinoid tumor as small-cell carcinoma in small crushed bronchial biopsies remains a significant potential problem in a worldwide sample of hospital settings. Careful evaluation of hematoxylin and eosin sections remains the most important tool for the differential diagnosis, with evaluation of tumor cell proliferation by Ki-67 (MIB-1) labeling index emerging from our review as the most useful ancillary technique for the distinction.

34BetaE12 expression along the whole spectrum of neuroendocrine proliferations of the lung, from neuroendocrine cell hyperplasia to small cell carcinoma

AIMS

Monoclonal antibody 34betaE12 (Ck34betaE12) recognizes a set of cytokeratins (1, 5, 10, 14) expressed in normal stratified squamous epithelium. We have recently reported its expression in squamous cell carcinoma and basaloid carcinoma, in contrast to large cell neuroendocrine carcinoma, an entity with overlapping morphological features with basaloid carcinoma. We have now examined the role of Ck34betaE12 in discriminating between neuroendocrine and non-neuroendocrine proliferations.

METHODS AND RESULTS

We performed an immunohistochemical study of 228 cases, comprising the whole spectrum of lung neuroendocrine proliferations and tumours. All cases of neuroendocrine cell hyperplasia (n = 15), tumorlet (n = 23), typical carcinoid (n = 27) and atypical carcinoid (n = 23) were completely negative for Ck34betaE12. Although the neuroendocrine cells of small cell lung carcinoma and large cell neuroendocrine carcinoma were consistently negative, a strong and diffuse positive staining was found in the non-neuroendocrine components of combined small cell carcinoma (three of eight cases) and combined large cell neuroendocrine carcinoma (11 of 12 cases). In addition, scattered Ck34betaE12+ cells were noted in 11 of 64 (17%) large cell neuroendocrine carcinoma and in seven of 56 (12.5%) small cell carcinoma, which were not obviously histologically combined. This heterogeneity of high-grade neuroendocrine tumours was not observed in carcinoids which lack Ck34betaE12 clusters of reactive cells. There was mutual exclusion between expression of neuroendocrine markers and that of Ck34betaE12.

CONCLUSION

We conclude that 34betaE12 expression excludes the neuroendocrine nature of tumour cells and uncovers the real frequency of combined forms in high-grade neuroendocrine tumours.

Focal neuroendocrine differentiation in non-small cell carcinoma is not predicted by pre-operative routine investigation

AIMS

Between 10 and 35% of resected non-small cell carcinomas of the lung show focal neuroendocrine differentiation. The significance of this is uncertain but recent studies have suggested that these tumours may be more responsive to chemotherapeutic agents than other non-small cell carcinomas. This study was undertaken to determine if focal neuroendocrine differentiation in surgically resected non-small cell carcinomas could be predicted in patients who had undergone traditional routine pre-operative diagnostic investigations.

METHODS

Sixty-six consecutive resections for non-small cell carcinoma were reviewed for the presence of focal neuroendocrine morphology or positive immunohistochemical staining with neuroendocrine markers. Pre-operative biopsy and cytology samples from these patients were then sought for similar assessment.

RESULTS

Ten of the 66 cases showed either morphological or immunohistochemical evidence of neuroendocrine differentiation. All 10 patients had undergone pre-operative investigation including bronchoscopy but in only four were pre-operative diagnostic samples obtained (two cytology and two biopsies). None of these specimens showed features to suggest the presence of neuroendocrine differentiation within the resected tumours.

CONCLUSION

The presence of focal neuroendocrine features in an unselected series of resected non-small cell carcinomas was not predicted by traditional pre-operative diagnostic investigations This indicates that focal neuroendocrine differentiation in patients with unresectable non-small carcinoma cannot be reliably identified for inclusion in clinical trials using traditional investigate approaches.

Detection of chromogranin A mRNA in small cell lung carcinoma using a new, highly sensitive in situ hybridization method with a non-radioisotope oligonucleotide probe

BACKGROUND

Immunoreactivity for chromogranin A (Cg A) is associated with the presence of neurosecretory granules in tumor cells, but immunohistochemical staining for Cg A may be absent in small cell lung carcinoma (SCLC), which has only a few secretory granules. Localization of Cg A mRNA is a useful indicator of the site of synthesis of a particular protein and possibly the rate of synthesis, and it is not dependent on posttranslation events within the cells. However, it is difficult to detect the low levels of mRNA copies using the standard non-radioisotope (RI) oligonucleotide probe.

METHODS

The authors analyzed Cg A mRNA in 20 cases of SCLC in formalin fixed, paraffin embedded tissue using a new, highly sensitive in situ hybridization method that was developed from the maximized immunohistochemistry (ImmunoMax) method. They also investigated Cg A mRNA in nonsmall cell lung carcinoma (NSCLC), including ten cases each of adenocarcinoma and squamous cell carcinoma of the lung.

RESULTS

All examined SCLC tissues showed a positive reaction for Cg mRNA. No NSCLC specimens showed any positive reaction for Cg A mRNA.

CONCLUSIONS

The detection of Cg A mRNA using the new, highly sensitive in situ hybridization method with a non-RI oligonucleotide probe can be used to characterize neuroendocrine differentiation of lung tumors even when the Cg A protein is not detected by immunohistochemistry. The authors believe this is a first step toward better diagnosis and treatment for patients with SCLC.

Neuroendocrine differentiation in lung cancer

The human lung has a resident population of neuroendocrine (NE) cells. These are characterised by the presence of neurosecretory granules and by a number of histochemical and immunocytochemical reactions. NE differentiation is a defining feature of classical and atypical carcinoid tumours and is seen in most small cell lung cancers (SCLC). Such differentiation has also been described in up to one third of non-small cell lung cancers (NSCLC). As demonstrated in an accompanying paper in this issue of the Journal, the reporting of NE differentiation varies with the technical approach used and with the nature of the tissue specimen. This phenomenon is a reflection of the histological and biological heterogeneity of lung cancer and has not been shown to be of clinical utility.

Creatine kinase activity and isoenzymes in lung, colon and liver carcinomas

We have compared the levels of creatine kinase (CK) activity and the distribution of CK isoenzymes determined by agarose gel electrophoresis in normal colon, liver and lung tissues, and in colon, liver and lung adenocarcinomas, lung squamous cell carcinomas and lung carcinoids. Colon and lung adenocarcinomas, and squamous cell carcinomas presented lower CK activity than the normal tissues and no differences were found between hepatocarcinoma and normal liver tissue. In contrast, lung carcinoids had higher CK activity than normal lung tissue. Type BB-CK was the predominant isoenzyme in normal lung, colon and liver tissues. Type MM isoenzyme was detected in normal lung and type MB-CK was found in normal colon. In most lung tumours the CK isoenzyme electrophoretic pattern did not change. However, no type BB-CK was detected in some hepatocarcinomas, type MM-CK decreased in lung carcinoids and type MB isoenzyme was not observed in colon adenocarcinomas. It is concluded that in most tumours there is a decrease in the expression of type B- and type M-CK subunits, whereas in lung carcinoid the expression of type B-CK activity increases. Thus, the increase in type BB-CK observed in the serum of patients with lung and colon adenocarcinomas is probably due mainly to enhanced enzyme release as a result of tumour cell necrosis.