The pulmonary Kulchitsky cell (neuroendocrine) cancers: from carcinoid to small cell carcinomas

Neuroendocrine neoplasms of the lung: The latest updates

Neuroendocrine neoplasms are a group of tumors with heterogenous malignancy that evolve from neuroendocrine cells, most frequently in the gastrointestinal tract and in the lung. The latest 2021 World Health Organization (WHO) classification of lung tumors defines neuroendocrine neoplasms of the lung as an independent group of tumors, including typical and atypical neuroendocrine tumors and small cell and large cell neuroendocrine carcinomas. Although the overall nomenclature is essentially unchanged from the fourth WHO classification, there are several clinically relevant updates. In this review article, we discuss the epidemiological, clinical, diagnostic, therapeutic and prognostic features of these fascinating neoplasms, including the latest insights, current challenges and future perspectives.

Best imaging signs identified by radiomics could outperform the model: application to differentiating lung carcinoid tumors from atypical hamartomas

OBJECTIVES

Lung carcinoids and atypical hamartomas may be difficult to differentiate but require different treatment. The aim was to differentiate these tumors using contrast-enhanced CT semantic and radiomics criteria.

METHODS

Between November 2009 and June 2020, consecutives patient operated for hamartomas or carcinoids with contrast-enhanced chest-CT were retrospectively reviewed. Semantic criteria were recorded and radiomics features were extracted from 3D segmentations using Pyradiomics. Reproducible and non-redundant radiomics features were used to training a random forest algorithm with cross-validation. A validation-set from another institution was used to evaluate of the radiomics signature, the 3D 'median' attenuation feature (3D-median) alone and the mean value from 2D-ROIs.

RESULTS

Seventy-three patients (median 58 years [43‒70]) were analyzed (16 hamartomas; 57 carcinoids). The radiomics signature predicted hamartomas vs carcinoids on the external dataset (22 hamartomas; 32 carcinoids) with an AUC = 0.76. The 3D-median was the most important in the model. Density thresholds < 10 HU to predict hamartoma and > 60 HU to predict carcinoids were chosen for their high specificity > 0.90. On the external dataset, sensitivity and specificity of the 3D-median and 2D-ROIs were, respectively, 0.23, 1.00 and 0.13, 1.00 < 10 HU; 0.63, 0.95 and 0.69, 0.91 > 60 HU. The 3D-median was more reproducible than 2D-ROIs (ICC = 0.97 95% CI [0.95‒0.99]; bias: 3 ± 7 HU limits of agreement (LoA) [- 10‒16] vs. ICC = 0.90 95% CI [0.85‒0.94]; bias: - 0.7 ± 21 HU LoA [- 4‒40], respectively).

CONCLUSIONS

A radiomics signature can distinguish hamartomas from carcinoids with an AUC = 0.76. Median density < 10 HU and > 60 HU on 3D or 2D-ROIs may be useful in clinical practice to diagnose these tumors with confidence, but 3D is more reproducible.

CRITICAL RELEVANCE STATEMENT

Radiomic features help to identify the most discriminating imaging signs using random forest. 'Median' attenuation value (Hounsfield units), extracted from 3D-segmentations on contrast-enhanced chest-CTs, could distinguish carcinoids from atypical hamartomas (AUC = 0.85), was reproducible (ICC = 0.97), and generalized to an external dataset.

KEY POINTS

• 3D-'Median' was the best feature to differentiate carcinoids from atypical hamartomas (AUC = 0.85). • 3D-'Median' feature is reproducible (ICC = 0.97) and was generalized to an external dataset. • Radiomics signature from 3D-segmentations differentiated carcinoids from atypical hamartomas with an AUC = 0.76. • 2D-ROI value reached similar performance to 3D-'median' but was less reproducible (ICC = 0.90).

Pulmonary Carcinoid Presenting as Multiple Subcutaneous Nodules

A 60-year-old female presented with a one-year history of multiple enlarging tender subcutaneous nodules. Initial biopsy demonstrated a poorly differentiated adenocarcinoma. Mammography showed multiple nodular breast lesions. After the patient failed to respond to tamoxifen, a second biopsy demonstrated a metastatic carcinoid tumor. Further search revealed a single small pulmonary nodule, which on aspiration biopsy proved to be a carcinoid tumor. The patient failed to respond to treatment with streptozotocin and 5'-fluorouracil. Therapy with leucovorin calcium and 5'-fluorouracil then produced a partial response.

Primary malignant pulmonary tumors in children: a review of the national cancer data base

BACKGROUND

The purpose is to delineate the clinical and pathological characteristics of rare primary malignant pulmonary tumors in children.

METHODS

Utilizing the National Cancer Data Base (NCDB), we analyzed all children (≤ 18 years) with a primary malignant pulmonary tumor from 1998 to 2011 to identify factors associated with better survival.

RESULTS

Of 211 children identified, the most common histology was carcinoid tumor (n=133, 63%) followed by mucoepidermoid carcinoma (MEC) (n=37, 18%), squamous cell carcinoma (SCC) (n=19, 9%), adenocarcinoma (n=16, 8%), bronchoalveolar carcinoma (BAC) (n=4, 2%), and small cell carcinoma (SCLC) (n=2, <1%). Factors that significantly affected survival include histology, race, tumor size, lymph node status, and extent of surgery. Patients with MEC and carcinoid tumors had a better overall survival compared to patients with other histologies (p<0.0001). The 5-year overall survival for MEC and carcinoid tumors was 100% and 95% (95% CI 87-98), respectively, versus 50% (95%CI 1-91) for BAC, 28% (95%CI 9-52) for SCC, and 26% (95%CI 5-55) for adenocarcinoma.

CONCLUSION

The majority of pediatric patients with a primary malignant pulmonary tumor present with carcinoid tumor or MEC and have an excellent prognosis. Lung cancers which are common in adults, but rare in children, have a worse prognosis.

Pulmonary carcinoid tumors

Carcinoid tumors of the lung are an uncommon group of neoplasms of neuroendocrine origin. Pulmonary carcinoid tumors are typically benign and slow growing. However, more aggressive subtypes may develop early nodal and distant metastases. Although several histologic classification strategies have been proposed to distinguish benign from more aggressive subtypes, the lack of uniformity in terminology has resulted in increased ambiguity and confusion. Because these tumors are generally resistant to chemotherapy, complete surgical resection is the primary form of therapy. Long-term survival for patients with typical carcinoid is excellent but is decreased in those with the atypical subtype. Complete tumor resection with preservation of uninvolved pulmonary parenchyma remains the fundamental goal in the surgical treatment of this unusual clinical entity.