The single-cell transcriptional landscape of lung carcinoid tumors

Lung carcinoid tumors, also referred to as pulmonary neuroendocrine tumors or lung carcinoids, are rare neoplasms of the lung with a more favorable prognosis than other subtypes of lung cancer. Still, some patients suffer from relapsed disease and metastatic spread while no consensus treatment exists for metastasized carcinoids. Several recent single-cell studies have provided detailed insights into the cellular heterogeneity of more common lung cancers, such as adeno- and squamous cell carcinoma. However, the characteristics of lung carcinoids on the single-cell level are yet completely unknown.To study the cellular composition and single-cell gene expression profiles in lung carcinoids, we applied single-cell RNA sequencing to three lung carcinoid tumor samples and normal lung tissue. The single-cell transcriptomes of carcinoid tumor cells reflected intertumoral heterogeneity associated with clinicopathological features, such as tumor necrosis and proliferation index. The immune microenvironment was specifically enriched in noninflammatory monocyte-derived myeloid cells. Tumor-associated endothelial cells were characterized by distinct gene expression profiles. A spectrum of vascular smooth muscle cells and pericytes predominated the stromal microenvironment. We found a small proportion of myofibroblasts exhibiting features reminiscent of cancer-associated fibroblasts. Stromal and immune cells exhibited potential paracrine interactions which may shape the microenvironment via NOTCH, VEGF, TGFβ and JAK/STAT signaling. Moreover, single-cell gene signatures of pericytes and myofibroblasts demonstrated prognostic value in bulk gene expression data.Here, we provide first comprehensive insights into the cellular composition and single-cell gene expression profiles in lung carcinoids, demonstrating the non-inflammatory and vessel-rich nature of their tumor microenvironment, and outlining relevant intercellular interactions which could serve as future therapeutic targets.

Video-assisted thoracoscopic parenchymal sparing “rotational” bronchoplasty for managing bronchial carcinoid tumor

We present a modified bronchoplasty technique involving rotation of the bronchial structures. Our goal was to reconstruct the bronchus without using any foreign material while fully preserving the parenchyma. We used a biportal VATS approach. The centrally located bronchial tumor at the juncture between the right main bronchus, the right upper lobe bronchus, and the bronchus intermedius was first resected. The right upper lobe bronchus was rotated caudally, toward the bronchus intermedius, together with a slight clockwise rotation posteriorly to facilitate the approximation and tension-free closure of the bronchial defect. This video tutorial demonstrates the operative steps and explains how the rotational aspect is achieved.

Single-Incision Port Robot-Assisted Surgery for Thymic Carcinoid Tumor Resection

Background: Multiple endocrine neoplasia (MEN) is divided into MEN type 1 (MEN-1) and MEN type 2 (MEN-2). MEN-1 may be associated with thymic carcinoid tumors. We present a case of the surgical removal of a thymic carcinoid associated with MEN-1 via a single-incision port RATS.Case presentation: A 39-year-old male patient with multiple endocrine neoplasia type 1 (MEN-1) who had an anterior mediastinal mass was referred to our hospital. The patient had undergone total parathyroidectomy and auto-transplantation of a partial parathyroid for hyperparathyroidism 6 years ago. Chest computed tomography revealed an isolated anterior mediastinal mass on the thymic gland with a maximum diameter measuring 22 mm. Thymic carcinoid tumor is classified as MEN-1 and has a poor prognosis, so we decided to remove the tumor. Single-incision port RATS was performed, and thymic carcinoid was confirmed in pathology.Conclusions: This report demonstrates that thymic carcinoid tumor removal is feasible and easy to perform via single-incision port RATS.

Adolescent Plaque Brachytherapy for Large Choroidal Metastasis from Lung Carcinoid Tumor

The purpose of this publication is to report a child with choroidal metastasis from a primary lung carcinoid tumor treated with 125-iodine plaque brachytherapy while achieving complete tumor regression. A 15-year-old girl with a history of stage IV lung carcinoid tumor developed painless progressive visual loss in her right eye. Ophthalmological exam documented a unilateral solitary large choroidal mass with complete exudative retinal detachment. Planned palliative treatment with plaque brachytherapy was performed utilizing a total dose of 45 Gy to the tumor apex. No tumor regression was noted after 6 months of follow-up. Ten months after primary therapy, re-treatment with a total dose of 90 Gy to the tumor apex was performed due to tumor progression. Complete regression was achieved after secondary treatment without evidence of recurrence after 18 months of follow-up. In conclusion, high-dose plaque brachytherapy may induce complete tumor regression in select adolescent patients with choroidal metastasis from lung carcinoid tumor.

Expression of Estrogen and Progesterone Receptors in a Tailgut Cyst with Carcinoid Tumor

Introduction/Objective Tailgut cysts (TC) are congenital lesions that arise in the presacral space. They originate from the embryonic hindgut and usually present between the ages of 30-60, with female predominance. TCs are usually asymptomatic or can present with lower back, perianal or pelvic pain. Malignant transformation of a TC is a rare complication, with adenocarcinoma being the most common, followed by carcinoid tumor. About thirty cases of carcinoid tumors arising in a TC have been reported in the literature so far with a slight female predominance (1.5:1). Methods/Case Report We describe a 40-year-old Hispanic woman with a 9-year history of cyclic pelvic pain related to her menstrual cycles. She was diagnosed with adenomyosis and underwent hysterectomy that did not completely resolve her symptoms. Follow-up serial imaging showed a growing complex-cystic presacral mass, which was eventually excised. Grossly, there was a 3.6×3.1×2.5 cm multiloculated cystic mass filled with mucoid material. Microscopically, there were multiple cystic spaces lined by benign squamous and mucinous columnar epithelium and surrounded by smooth muscle cells. A 6-mm carcinoid tumor was found within a cyst wall and confirmed by positive synaptophysin and chromogranin staining with a Ki-67 proliferation index of <2%. Estrogen and progesterone receptor immunostains were positive in the epithelial cyst linings and the stromal cells but not in the carcinoid tumor cells. Results (if a Case Study enter NA) NA Conclusion We conclude that the diagnosis of TC should be considered in the differential of gynecologic patients with unresolved cyclic pelvic pain and that estrogen and progesterone could have an important role in the pathogenesis of TCs. Furthermore, estrogen receptors can be a therapeutic target in patients with this entity.