Role of orthopedia homebox protein in subclassification of pulmonary carcinoid tumors: Retrospective analysis of 110 cases

Background

Orthopedia homeobox protein (OTP), highlighted as a sensitive and specific marker for pulmonary carcinoids, may provide a more objective criterion for subclassification.

Materials and Methods

A total of 110 patients who underwent surgery for pulmonary carcinoids (2009-2019) were included. Gender, age, application complaint, tumor diameter and location, typical and atypical tumor type, lymph node involvement, stage, recurrence, and survival data were evaluated retrospectively with OTP nuclear staining.

Results

The sensitivity of OTP was 66.4%. OTP in subclassifying pulmonary carcinoids was not significant. There was no significant relationship between OTP and lymph node involvement, recurrence, and survival.

Conclusion

OTP does not provide significant results in the subclassification of typical and atypical carcinoid tumors and the evaluation of recurrence and survival of carcinoid tumor cases.

A Systematic Review on Combined [18F]FDG and 68Ga-SSA PET/CT in Pulmonary Carcinoid

Pulmonary carcinoids (PCs) are part of a spectrum of well-differentiated neuroendocrine neoplasms (NENs) and are classified as typical carcinoid (TC) and atypical carcinoid (AC). TC differ from AC not only for its histopathological features but also for its "functional imaging pattern" and prognosis. ACs are more undifferentiated and characterized by higher aggressiveness. Positron emission tomography/computed tomography (PET/CT) with somatostatin analogs (SSA) labeled with Gallium-68 (⁶⁸Ga-DOTA-TOC, ⁶⁸Ga-DOTA-NOC, ⁶⁸Ga-DOTA-TATE) has widely replaced conventional imaging with gamma camera using ¹¹¹In- or ^99mTc-labelled compounds and represents now the gold standard for diagnosis and management of NENs. In this setting, as already described for gastro-entero-pancreatic NENs, ¹⁸F-Fluorodeoxiglucose ([¹⁸F]FDG) in addition to ⁶⁸Ga-SSA can play an important role in clinical practice, particularly for ACs that show a more aggressive behavior compared to TCs. The aim of this systematic review is to analyze all original studies collected from the PubMed and Scopus databases regarding PCs in which both ⁶⁸Ga-SSA PET/CT and [¹⁸F]FDG PET/CT were performed in order to evaluate the clinical impact of each imaging modality. The following keywords were used for the research: "¹⁸F, ⁶⁸Ga and (bronchial carcinoid or carcinoid lung)". A total of 57 papers were found, of which 17 were duplicates, 8 were reviews, 10 were case reports, and 1 was an editorial. Of the remaining 21 papers, 12 were ineligible because they did not focus on PC or did not compare ⁶⁸Ga-SSA and [¹⁸F]FDG. We finally retrieved and analyzed nine papers (245 patients with TCs and 110 patients with ACs), and the results highlight the importance of the combined use of ⁶⁸Ga-SSA and [¹⁸F]FDG PET/CT for the correct management of these neoplasms.

Improvement of Lung NET Management through Standardized Care-A Swiss Nationwide Observational Study

Typical (TC) and atypical carcinoids (AC) are the most common neuroendocrine tumors (NETs) of the lung. Because these tumors are rare, their management varies widely among Swiss centers. Our aim was to compare the management of Swiss patients before and after the publication of the expert consensus of the European Neuroendocrine Tumor Society (ENETS) in 2015. We used data from the Swiss NET registry from 2009 to 2021 with patients with TC and AC. Survival analysis was performed using the Kaplan-Meier method and log-rank test. Overall, 238 patients were included, 76% (180) thereof with TC and 24% (58) with AC, including 155 patients before and 83 patients after 2016. An increase in the use of functional imaging was observed, 16% (25) before and 35% (29) after 2016, p < 0.001. The presence of SST_2A-receptors was determined more often: 32% (49 times) before 2016 and 47% (39 times) after, p = 0.019. Concerning therapy, higher removal of lymph nodes after 2016 was observed, 54% (83) before versus 78% (65) after, p < 0.001. Median overall survival for patients with AC was significantly shorter, with 89 months compared to 157 months for patients with TC, p < 0.001. While the implementation of a more standardized approach was observed over the years, there is still room for amelioration in the management of TC and AC in Switzerland.

Clinical efficacy of thermal ablation for the treatment of pulmonary carcinoid tumor: a propensity-matched analysis

OBJECTIVE

To investigate the clinical efficacy of thermal ablation in the treatment of pulmonary carcinoid (PC) tumor.

METHODS

Data of patients with inoperable PC diagnosed from 2000 to 2019 were obtained from the SEER database and analyzed according to different therapeutic modality: thermal ablation vs non-ablation. Propensity score matching (PSM) was used to reduce intergroup differences. Kaplan-Meier curves and the log-rank test were used to compare intergroup differences of overall survival (OS) and lung cancer-specific survival (LCSS). Cox proportional risk models were used to reveal prognostic factors.

RESULTS

After PSM, the thermal ablation group had better OS (p < .001) and LCSS (p < .001) than the non-ablation group. Subgroup analysis stratified by age, sex, histologic type and lymph node status subgroups showed similar survival profile. In the subgroup analysis stratified by tumor size, the thermal ablation group showed better OS and LCSS than those of the non-ablation group for tumors ≤3.0 cm, not statistically significant for tumors >3.0 cm. Subgroup analysis by M stage showed that thermal ablation was superior to non-ablation in OS and LCSS for patients with M0 stage, but no significant difference was found in subgroups with distant metastatic disease. Multivariate analysis showed that thermal ablation was an independent prognostic factor for OS (HR: 0.34, 95% CI: 0.25-0.46, p < .001) and LCSS (HR: 0.23, 95%CI: 0.12-0.43, p < .001).

CONCLUSION

For patients with inoperable PC, thermal ablation might be a potential treatment option, especially in M0-stage with tumor size ≤3 cm.

A Multimodal Biomarker Predicts Dissemination of Bronchial Carcinoid

Background: Curatively treated bronchial carcinoid tumors have a relatively low metastatic potential. Gradation into typical (TC) and atypical carcinoid (AC) is limited in terms of prognostic value, resulting in yearly follow-up of all patients. We examined the additional prognostic value of novel immunohistochemical (IHC) markers to current gradation of carcinoids. Methods: A retrospective single-institution cohort study was performed on 171 patients with pathologically diagnosed bronchial carcinoid (median follow-up: 66 months). The risk of developing distant metastases based on histopathological characteristics (Ki-67, p16, Rb, OTP, CD44, and tumor diameter) was evaluated using multivariate regression analysis and the Kaplan−Meier method. Results: Of 171 patients, seven (4%) had disseminated disease at presentation, and 164 (96%) received curative-intent treatment with either endobronchial treatment (EBT) (n = 61, 36%) or surgery (n = 103, 60%). Among the 164 patients, 13 developed metastases at follow-up of 81 months (IQR 45−162). Univariate analysis showed that Ki-67, mitotic index, OTP, CD44, and tumor diameter were associated with development of distant metastases. Multivariate analysis showed that mitotic count, Ki-67, and OTP were independent risk factors for development of distant metastases. Using a 5% cutoff for Ki-67, Kaplan−Meier analysis showed that the risk of distant metastasis development was significantly associated with the number of risk predictors (AC, Ki-67 ≥ 5%, and loss of OTP or CD44) (p < 0.0001). Six out of seven patients (86%) with all three positive risk factors developed distant metastasis. Conclusions: Mitotic count, proliferation index, and OTP IHC were independent predictors of dissemination at follow-up. In addition to the widely used carcinoid classification, a comprehensive analysis of histopathological variables including Ki-67, OTP, and CD44 could assist in the determination of distant metastasis risks of bronchial carcinoids.

Differential Orthopedia Homeobox expression in pulmonary carcinoids is associated with changes in DNA methylation

Limited number of tumor types have been examined for Orthopedia Homeobox (OTP) expression. In pulmonary carcinoids, loss of expression is a strong indicator of poor prognosis. Here, we investigated OTP expression in 37 different tumor types, and the association between OTP expression and DNA methylation levels in lung neuroendocrine neoplasms. We analyzed publicly available multi-omics data (whole-exome-, whole-genome-, RNA sequencing and Epic 850K-methylation array) of 58 typical carcinoids, 27 atypical carcinoids, 69 large cell neuroendocrine carcinoma and 51 small cell lung cancer patients and TCGA (The Cancer Genome Atlas) data of 33 tumor types. 850K-methylation analysis was cross-validated using targeted pyrosequencing on 35 carcinoids. We report bimodality of OTP expression in carcinoids (OTPhigh vs OTPlow group, likelihood-ratio test P = 1.5 × 10-2 ), with the OTPhigh group specific to pulmonary carcinoids while absent from all other cohorts analyzed. Significantly different DNA methylation levels were observed between OTPhigh and OTPlow carcinoids in 12/34 OTP infinium probes (FDR < 0.05 and β-value effect size > .2). OTPlow carcinoids harbor high DNA methylation levels as compared to OTPhigh carcinoids. OTPlow carcinoids showed a significantly worse overall survival (log-rank test P = .0052). Gene set enrichment analysis for somatically mutated genes associated with hallmarks of cancer showed robust enrichment of three hallmarks in the OTPlow group, that is, sustaining proliferative signaling, evading growth suppressor and genome instability and mutation. Together our data suggest that high OTP expression is a unique feature of pulmonary carcinoids with a favorable prognosis and that in poor prognostic patients, OTP expression is lost, most likely due to changes in DNA methylation levels.

Neuroendocrinology of the lung revealed by single-cell RNA sequencing

Pulmonary neuroendocrine cells (PNECs) are sensory epithelial cells that transmit airway status to the brain via sensory neurons and locally via calcitonin gene-related peptide (CGRP) and γ- aminobutyric acid (GABA). Several other neuropeptides and neurotransmitters have been detected in various species, but the number, targets, functions, and conservation of PNEC signals are largely unknown. We used scRNAseq to profile hundreds of the rare mouse and human PNECs. This revealed over 40 PNEC neuropeptide and peptide hormone genes, most cells expressing unique combinations of 5-18 genes. Peptides are packaged in separate vesicles, their release presumably regulated by the distinct, multimodal combinations of sensors we show are expressed by each PNEC. Expression of the peptide receptors predicts an array of local cell targets, and we show the new PNEC signal angiotensin directly activates one subtype of innervating sensory neuron. Many signals lack lung targets so may have endocrine activity like those of PNEC-derived carcinoid tumors. PNECs are an extraordinarily rich and diverse signaling hub rivaling the enteroendocrine system.

The Cancers-Specific Survival of Metastatic Pulmonary Carcinoids and Sites of Distant Metastasis: A Population-Based Study

Background:

Lung cancer is the leading cause of cancer-related deaths and pulmonary carcinoids (PCs) account for almost 2% of all pulmonary malignancies. However, few published articles have reported prognosis and related factors of pulmonary carcinoid patients.

Material and Method:

The Surveillance, Epidemiology, and End Results (SEER) database was used to collect data of patients diagnosed with metastatic PCs from 2010 to 2016. The prognosis and survival of these patients were compared by employing Cox proportional hazards and the Kaplan-Meier survival analysis.

Results:

A total of 1763 patients were analyzed. The liver (668, 25.6%) was shown to be the most common metastatic site in the isolated organ metastasis cohort, followed by the lung (636, 24.4%), bone (562, 21.6%), and brain (460, 17.6%). Among the patients, the tumor metastasized to a single distant site included the liver, bone, lung, and brain. Cancer-specific survival (CSS) in metastatic PCs is determined by the site of metastasis and the total number of such sites. Pulmonary carcinoid patients with isolated liver metastasis manifested more favorable survival rates in comparison to patients having isolated metastasis in the lung, brain, or bone. The median CSS was 45, 7, 6, 5 months (P = 0.011). The number of distant metastatic sites and the location of distant metastasis were found to be independent risk factors for CSS. For patients with distant isolated metastasis, liver metastasis (P < 0.0001) had better CSS in comparison to those with bone metastasis. When compared to patients whose carcinoids had metastasized to the bones, patients with a brain (P = 0.273) or lung (P = 0.483) metastasis had the same CSS.

Conclusion:

Cancer-specific survival in metastatic PCs depends on the site of metastasis and the total number of such locations. PC patients with isolated liver metastasis manifested more favorable survival in comparison to patients with isolated metastasis in the lung, brain, or bone.

Pulmonary carcinoid tumours: A multi-centre analysis of survival and predictors of outcome following sublobar, lobar, and extended pulmonary resections

BACKGROUND

Pulmonary carcinoids are rare neoplasms, accounting for approximately 1%-2% of all lung malignancies. A retrospective analysis was undertaken of all patients who underwent surgical resection of pulmonary carcinoid tumours across multiple institutions in Melbourne, Australia.

METHODS

From May 2000 through April 2020, 241 patients who underwent surgical resection of pulmonary carcinoid tumours were retrospectively reviewed. Patient demographics, pathologic data, and long-term outcomes were recorded.

RESULTS

Median age was 57.7 years and the majority of patients were female (58.9% vs. 41.1%). Typical carcinoid was present in 77.1%. Histological subtype was associated with several factors. Atypical carcinoid was more likely to have larger tumour size and nodal involvement. Overall survival for typical carcinoid at 5, 10, and 15 years was 98%, 95%, and 84%, and for atypical carcinoid was 88%, 82%, and 62%, respectively. Histological subtype and age were found to be independent predictors of overall survival, with worse outcomes for atypical and those above 60 years of age. Disease-free survival was related to sublobar resection (p < 0.001, sub-hazard ratio (SHR): 6.89), lymph node involvement (p = 0.022, SHR: 3.18), and atypical histology (p < 0.001, SHR: 9.89).

CONCLUSION

Excellent long-term outcomes can be achieved following surgical resection of pulmonary carcinoids. Atypical histology and lymph node involvement are significant prognostic factors, and sublobar resection should not be considered in patients with either of the above features. Typical carcinoid tumour without nodal involvement may be appropriate for sublobar resection. Typical and atypical carcinoid tumours should be considered distinct disease entities, and as such treated accordingly.

Case Report: A Challenging Localization of a Pulmonary Ectopic ACTH-Secreting Tumor in a Patient With Severe Cushing's Syndrome

BACKGROUND

Ectopic adrenocorticotropic syndrome (EAS) is a rare cause of endogenous ACTH-dependent Cushing's syndrome, usually associated with severe hypercortisolism as well as comorbidities. Tumor detection is still a challenge and often requires several imaging procedures. In this report, we describe a case of an ectopic ACTH secretion with a misleading localization of the responsible tumor due to a concomitant rectal carcinoma.

CASE PRESENTATION

A 49-year-old man was referred to our Endocrinology Unit due to suspicion of Cushing's syndrome. His medical history included metastatic rectal adenocarcinoma, diagnosed 5 years ago and treated with adjuvant chemotherapy, radiotherapy and surgical resection. During follow-up, a thoracic computed tomography scan revealed two pulmonary nodules located in the superior and middle lobes of the right lung with a diameter of 5 and 10 mm, respectively. However, these nodules remained radiologically stable thereafter and were not considered relevant. All biochemical tests were suggestive of EAS (basal ACTH levels: 88.2 ng/L, nv 0-46; basal cortisol levels: 44.2 µg/dl, nv 4.8-19.5; negative response to CRH test and high dose dexamethasone suppression test) and radiological localization of the ectopic ACTH-secreting tumor was scheduled. The CT scan revealed a dimensional increase of the right superior lung nodule (from 5 to 12 mm). [⁶⁸Ga]-DOTA-TOC PET/CT scan was negative, while [¹⁸F]-FDG-PET/CT showed a tracer accumulation in the superior nodule. After a multidisciplinary consultation, the patient underwent thoracic surgery that started with two atypical wedge resections of nodules. Frozen section analyses showed a neuroendocrine tumor on the right middle lobe nodule and a metastatic colorectal adenocarcinoma on the superior lesion. Then, a right superior nodulectomy and a right middle lobectomy with mediastinal lymphadenectomy were performed. The final histopathological examination confirmed a typical carcinoid tumor, strongly positive for ACTH. A post-surgical follow-up showed a persistent remission of Cushing's syndrome.

CONCLUSIONS

The present report describes a case of severe hypercortisolism due to EAS not detected by functional imaging methods, in which the localization of ACTH ectopic origin was puzzled by a concomitant metastatic rectal carcinoma. The multidisciplinary approach was crucial for the management of this rare disease.

Diagnosis and management of small pulmonary atypical carcinoid tumor associated with Cushing syndrome

Ectopic adrenocorticotropic hormone (ACTH) syndrome is rare and identification of its source is often challenging. We report the case of an ectopic Cushing syndrome in a young adult male secondary to an occult ACTH producing atypical carcinoid tumor. Extensive biochemical and imaging workup was unrevealing. The diagnosis was aided by Ga-DOTA PET scan demonstrating a suspicious left upper lobe lung nodule. The patient underwent video-assisted thoracoscopic exploration with wedge resection and mediastinal lymphadenectomy of a T2aN2M0 atypical carcinoid, resulting in the normalization of ACTH levels and complete resolution of symptoms. The role of a Ga-DOTA PET scan in diagnosing pulmonary carcinoid tumors and their management are discussed.

Orthopedia Homeobox (OTP) in Pulmonary Neuroendocrine Tumors: The Diagnostic Value and Possible Molecular Interactions

Generally, patients with stage I-IIIa (TNM) pulmonary carcinoid disease have a favourable prognosis after curative resection. Yet, distant recurrence of disease after curative surgery occurs in approximately 1–6% of patients with typical carcinoid and 14–29% in patients with atypical carcinoid disease, respectively. Known predictors of distant recurrence of disease are atypical carcinoid, lymphatic involvement, and incomplete resection status. However, none of them can be reliably used, alone or in combination, to exclude patients from long-term follow-up (advised 15 years). By genomic profiling, Orthopedia homeobox (OTP) has been identified as a promising prognostic marker for pulmonary carcinoid with a favourable prognosis and low risk of distant disease recurrence. Moreover, OTP is a highly specific marker for carcinoids of pulmonary origin and recent genome wide analysis has identified OTP as a crucial predictor of aggressive tumor behaviour. OTP in combination with CD44, a stem cell marker and cell-surface protein, enables the identification of patients with surgical resected carcinoid disease that could potentially be excluded from long-term follow-up. In future clinical practice OTP may enable clinicians to reduce the diagnostic burden and related distress and reduce costs of long-term radiological assessments in patients with a pulmonary carcinoid. This review addresses the current clinical value of OTP and the possible molecular mechanisms regulating OTP expression and function in pulmonary carcinoids.

Pulmonary Carcinoid Surface Receptor Modulation Using Histone Deacetylase Inhibitors

Pulmonary carcinoids are a type of neuroendocrine tumor (NET) accounting for 1–2% of lung cancer cases. Currently, Positron Emission Tomography (PET)/CT based on the radiolabeled sugar analogue [¹⁸F]-FDG is used to diagnose and stage pulmonary carcinoids, but is suboptimal due to low metabolic activity in these tumors. A new technique for pulmonary carcinoid imaging, using PET/CT with radiolabeled somatostatin analogs that specifically target somatostatin receptor subtype 2 (SSTR2), is becoming more standard, as many tumors overexpress SSTR2. However, pulmonary carcinoid patients with diminished SSTR2 expression are not eligible for this imaging or any type of SSTR2-specific treatment. We have found that histone deacetylase (HDAC) inhibitors can upregulate the expression of SSTR2 in pulmonary carcinoid cell lines. In this study, we used a non-cytotoxic dose of HDAC inhibitors to induce pulmonary carcinoid SSTR2 expression in which we confirmed in vitro and in vivo. A non-cytotoxic dose of the HDAC inhibitors: thailandepsin A (TDP-A), romidepsin (FK228), suberoylanilide hydroxamic acid (SAHA), AB3, and valproic acid (VPA) were administered to promote SSTR2 expression in pulmonary carcinoid cell lines and xenografts. This SSTR2 upregulation technique using HDAC inhibitors could enhance radiolabeled somatostatin analog-based imaging and the development of potential targeted treatments for pulmonary carcinoid patients with marginal or diminished SSTR2 expression.

The utility of 18F-FDG and 68Ga-DOTA-Peptide PET/CT in the evaluation of primary pulmonary carcinoid: A systematic review and meta-analysis

BACKGROUND

Pulmonary carcinoids (PC) are histologically classified into typical carcinoid (TC) and atypical carcinoid (AC). The diagnosis of pulmonary carcinoid and possibly the differentiation between TC and AC could make a significant effect on the treatment planning as well as prognosis. Several studies have explored the utility of Ga-DOTA-Peptide (Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-peptide) and F-flurodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) in the evaluation of primary pulmonary carcinoids. Therefore, we performed a meta-analysis to evaluate the diagnostic accuracy and prediction efficiency of histological subtypes of these two imaging modalities in primary PC.

METHODS

Relevant studies were identified by searching PubMed, Web of Science, and EMBASE published from 2006 to 2016. Two authors extracted characteristics of patients and their lesions using predefined criteria.

RESULTS

Fourteen studies comprising 352 patients were included in this meta-analysis. The pooled sensitivity of Ga-DOTA-Peptide and F-FDG PET/CT in detecting pulmonary carcinoid were 90.0% (95% CI = 82.0-95.0%; P = .07; I = 49.6%) and 71.0% (95% CI = 66.0-76.0%; P < .001; I = 59.3%), respectively. An SUVmax ratio between Ga-DOTA-Peptide and F-FDG higher than the cutoff value of 4.28 was predictive of TC with 89.3% sensitivity and 100% specificity (AUC, 96.4%; 95% CI, 91.1-100%). The ratio of tumor uptake to atelectatic lung uptake was significantly higher for Ga-DOTA-peptide (2.5-91, mean 30.5 ± 28.1) than for F-FDG (0.3-10.3, mean 2.1 ± 2.3) (P < .001).

CONCLUSIONS

Both Ga-DOTA-peptide and F-FDG are highly sensitive in detecting pulmonary carcinoid, while Ga-DOTA-peptide is more sensitive than F-FDG (90.0% vs 71.0%). The SUVmax ratio was an accurate predictor of the histopathologic variety of the carcinoid tumor, and Ga-DOTA-peptide was better than F-FDG in cases with atelectasis.

Inflammation and PD-L1 expression in pulmonary neuroendocrine tumors

In the light of novel cancer immune therapies, the status of antitumor inflammatory response and its regulation has gained much attention in patients with lung cancer. Ample datasets exist for non-small-cell lung cancer, but those for pulmonary neuroendocrine tumors are scarce and controversial. Here, tumor-associated inflammation, CD8+ cell infiltration and PD-L1 status were evaluated in a cohort of 57 resected carcinoids and 185 resected neuroendocrine carcinomas of the lung (58 large cell carcinomas and 127 small cell carcinomas). Data were correlated with clinicopathological factors and survival. Moderate or high tumor-associated inflammation was detected in 4 carcinoids (7%) and in 37 neuroendocrine carcinomas (20%). PD-L1 immunoreactivity was seen in immune cells of 73 (39%) neuroendocrine carcinomas, while tumor cells were labeled in 21 (11%) cases. Inflammatory cells and tumor cells in carcinoids lacked any PD-L1 expression. In neuroendocrine carcinomas, PD-L1 positivity in immune cells, but not in tumor cells, was associated with intratumoral CD8+ cell infiltration (P < 0.001), as well as with the severity of tumor-associated inflammation (P < 0.001). In neuroendocrine carcinomas, tumor-associated inflammation and PD-L1 positivity in immune cells correlated with prolonged survival and the latter factor was also an independent prognosticator (P < 0.01, hazard ratio 0.4 for overall survival, P < 0.001 hazard ratio 0.4 for disease-free survival). Taken together, in neuroendocrine tumors, antitumor inflammatory response and PD-L1 expression are largely restricted to neuroendocrine carcinomas, and in this tumor entity, PD-L1 expression in inflammatory cells is positively correlated to patient survival.

Subcutaneous metastasis of a pulmonary carcinoid tumor: A case report

RATIONALE

Carcinoid tumors are derived from neuroendocrine cells and are most frequently found in the gastrointestinal tract and bronchopulmonary system. They are generally characterized by an indolent clinical course but may in some instances spread to regional lymph nodes or to distant sites. Subcutaneous metastases of carcinoid tumors are extremely rare; there are only few cases reported in the literature and the site of the primary tumor was mainly the gastrointestinal tract. Also, the diagnosis of this type of lesions many years after the surgical resection of the pulmonary carcinoid (PC) could be a challenge for clinicians.

PATIENT CONCERNS

A nonsmoker woman diagnosed with a atypical carcinoid stage IA2 maintained follow-up at our institution. Seven years later she incidentally detected a subcutaneous nodular lesion in the lumbar region.

DIAGNOSES

A positron emission tomography-computed tomography (PET/CT) was performed and showed pathological uptake of the refered lesion. An excisional biopsy was performed and with the support of immunohistochemistry the diagnosis of a subcutaneous metastasis from a pulmonary atypical carcinoid was made.

INTERVENTIONS

The patient initiated chemotherapy with carboplatin plus etoposide and complied 4 cycles of treatment.

OUTCOMES

She maintained tight follow-up at our center and for 12 months there were no signs of relapse.

LESSONS

This extremely rare case highlights the difficulties in the differential diagnosis and the importance of diagnostic tests as PET/CT and immunohistochemistry in the establishment of a diagnosis. Physicians should be aware of signs of skin metastasis from lung malignancies even if the prognosis is good or many years have passed since the surgical resection.

Improvement in TNM staging of pulmonary neuroendocrine tumors requires histology and regrouping of tumor size

OBJECTIVE

Neuroendocrine tumors of the lung are currently staged with the 7th edition TNM non-small cell lung cancer staging system. This decision, based on data analysis without data on histology or disease-specific survival, makes its applicability limited. This study proposes a specific staging system for these tumors.

METHODS

We retrospectively analyzed 510 consecutive patients (female/male, 313/197; median age, 61 years; interquartile range, 51-70) undergoing lung resection for a primary neuroendocrine tumor between 2000 and 2015 in 8 centers. Multivariable analysis was performed using a Cox proportional hazard model to identify factors associated with disease-specific survival. A new staging system was proposed on the basis of the results of this analysis. Kaplan-Meier disease-specific survival was analyzed by stage using the proposed and the 7th TNM staging system.

RESULTS

Follow-up was completed in 490 of 510 patients at a median of 51 months (interquartile range, 18-99). Histology (G1-typical carcinoid vs G2-atypical carcinoid vs G3-large-cell neuroendocrine carcinoma) and pT were independently associated with survival, but pN was not. After regrouping histology and pT, we proposed the following staging system: IA (pT1-2G1), IB (pT3G1, pT1G2), IIA (pT4G1, pT2-3G2, pT1G3), IIB (pT4G2, pT2-3G3), and III (pT4G3). The 5-year survivals were 97.9%, 81.0%, 69.1%, 51.8%, and 0%, respectively. By using the 7th TNM, 5-year survivals were 95.0%, 92.3%, 67.7%, 70.9%, and 65.1% for stage IA, IB, IIA, IIB, and III, respectively.

CONCLUSIONS

Incorporating histology and regrouping tumor stage create a unique neuroendocrine tumor staging system that seems to predict survival better than the 7th TNM classification.

Solitary splenic metastasis of pulmonary carcinoid: A rare case report and literature review

We herein report a rare case of solitary splenic metastasis of a pulmonary carcinoid, for which hand-assisted laparoscopic splenectomy was performed. A 73-year-old man was admitted to the Inoue Hospital (Fukuyama, Japan) in March 2015 with an abnormal shadow of the spleen. The patient had a history of right upper lobectomy with lymph node dissection for a pulmonary typical carcinoid (pT1N0M0 stage IA) 7 years earlier. Plain abdominal computed tomography (CT) revealed a low-density area in the spleen. Enhanced abdominal CT revealed a mass in the spleen measuring 3×3 cm. Blood tests and tumor marker analysis revealed no abnormalities. Abdominal magnetic resonance imaging revealed a mass that was low-intensity on T1- and high-intensity on T2-weighted images, and positron emission tomography revealed abnormal fluorodeoxyglucose accumulation in the mass. Hand-assisted laparoscopic splenectomy was performed for diagnosis and treatment. The resected specimen included a reddish-brown mass. On immunohistochemistry, the mass was positive for chromogranin A, synaptophysin and CD56, which was similar to the resected pulmonary carcinoid tumor; thus, splenic metastasis of pulmonary carcinoid was diagnosed. The postoperative course was uneventful and the patient is currently under observation and remains recurrence-free, with no adjuvant chemotherapy.

Overexpression of PY1289-HER3 in sporadic pulmonary carcinoid from patients bearing MEN1 gene variants

The present study aimed to investigate the expression of human epidermal growth factor receptors (HERs) (HER1/HER2/HER3/HER4) and their phosphorylated forms (p-HER1/p-HER2/p-HER3/p-HER4) in pulmonary carcinoids (PCs). HER and p-HER protein expression was assessed by immunohistochemistry on tissue microarrays in 37 specimens of sporadic PCs, 29 typical carcinoids (TCs) and 8 atypical carcinoids (ACs). When compared with the ACs, the TCs did not exhibit any differences in terms of HER/p-HER expression. The tumors of this study have previously been characterized for the expression of menin and the mutational status of menin 1 (MEN1), a gene strongly implicated in the pathogenesis of PCs. In the present study, it was found that the cytoplasmic (‘disarrayed’), but not nuclear (‘arrayed’) expression of menin was positively correlated with HER3 (P=0.004), HER4 (P=0.015), p-HER1 (P=0.005), p-HER3 (P<0.001), and p-HER4 (P=0.001) expression. Moreover, HER3 and p-HER3 were found to be significantly more expressed in PCs with MEN1 variants, than in tumors with MEN1 wild-type (P=0.000 and P=0.025, respectively). These findings suggest the potential clinical use of HER inhibitors in the treatment of patients with PCs, particularly for individuals with p-HER3-positive PCs harboring MEN1 gene variants.

111In-Pentetreotide SPECT/CT in Pulmonary Carcinoid

AIM

We evaluated somatostatin receptor scintigraphy (SRS) with (111)In-pentetreotide incremental value in pulmonary carcinoid (PC) diagnosis compared to contrast enhanced Computed Tomography (ceCT).

PATIENTS AND METHODS

We enrolled 81 patients with ascertained PC, 39 at initial staging and 42 in follow-up; the primary tumor had already been excised in 68 cases. Single Photon emission Computed Tomography (SPECT) images were reconstructed with the iterative method and fused with non-enhanced Computed tomography (CT) images.

RESULTS

Primary PC or metastatic lesions were ascertained in 55/81 patients and SPECT/CT was positive in 50/55 cases, while ceCT was positive in 44/55. Comparing SPECT/CT with ceCT results, we found a sensitivity of 96 vs. 87.5%, and specificity of 92% vs. 97% for the detection of primary lesion or recurrent disease. A total of 198 lesions were ascertained at SPECT/CT, while 161 at ceCT, with values of sensitivity and specificity of 85.5% and 84.6% for SRS and 75.2% and 90.5% respectively.

CONCLUSION

(111)In-Pentetreotide SPECT/CT proved to be more sensitive and accurate than ceCT, thus enhancing its role in evaluating patients with PC.

Excessive muscle paralysis due to pulmonary carcinoid -a case report

We present the case of a 58-year-old woman with a renin secreting typical bronchopulmonary carcinoid. This patient showed hypotension, constipation and fatigue due to extensive hypokaliemia (K =1.9 meq/L). Aldosterone (102.7 ng/100 mL) and renin (46 ng/mL) were excessively elevated at that time, but cortisol level was normal. Routine chest roentgenography and computed tomography revealed a nodular lesion in the upper left lung lobe, which was suspicious for a neurosecretory pulmonary tumor. The final diagnosis was made by using bronchoscopic procedures and the histologically diagnosis was compatible as a typical pulmonary carcinoid. The tumor was resected curatively, and the renin and aldosterone level became normal. A year after the patient looks healthy.