Recent updates in salivary gland tumors of the lung

Primary low-grade salivary gland-type intraductal carcinoma of the lung with CCDC6::RET fusion: Case presentation and literature review

OBJECTIVES

Salivary gland-type intraductal carcinoma (IC) is a rare type of low-grade salivary gland neoplasm. Given that the clinical and imaging features of primary lung IC are nonspecific, the diagnosis requires pathologic analysis.

METHODS

We report a 63-year-old woman with primary low-grade salivary gland-type IC of the lung, characterized by an origin from the bronchus submucosa, an intraductal or intracavity growth of ductal epithelium, an absence of interstitial infiltration, and harboring an RET::CCDC6 fusion.

RESULTS

Through case presentation and a literature review, we discuss the differential diagnosis and clinical management of salivary gland-type IC of the lung.

CONCLUSIONS

Molecular testing is not necessary for histologic subtyping but can aid in the differential diagnosis of IC.

Collision tumor consisting of primary mucoepidermoid carcinoma and adenocarcinoma in the lung: a case report and literature review

Mucoepidermoid carcinoma in the lung is uncommon, while the occurrence of a collision tumor consisting of primary mucoepidermoid carcinoma (MEC) and typical adenocarcinoma is extremely rare. We report a case of a 70-year-old female with the presence of a nodule in her right lung. The pathological examination revealed a primary collision tumor consisting of invasive adenocarcinoma and mucoepidermoid carcinoma. Manual microdissection was performed to selectively isolate the MEC and adenocarcinoma components, followed by exome sequencing which unveiled identical mutations in both components, suggesting their monoclonal origins with divergent differentiation. Clinical awareness and recognition of such collision tumors are crucial, as they will determine appropriate treatment strategies based on the individual biological aggressiveness of each tumor component.

Bronchial Basaloid Papillary Tumor of Uncertain Malignant Potential: A Case Report

Bronchial papillomas are benign tumors, which can be divided into different subtypes based on the cellular features. So far, no bronchial papilloma with basaloid cell features has been reported. We report a bronchial basaloid papillary tumor in a 67-year-old woman. Tumor recurrence and malignant transformation were observed after a long-term follow-up. The clinical, histological, immunohistochemical, and genetic features were reappraised. The primary tumor was characterized by papillary growth pattern and basaloid neoplastic cells, only a small amount of neoplastic cells showed mature characteristics. The tumor originated from respiratory epithelium and had a low proliferation index by Ki-67. Keratin (KRT) 5/6 and KRT7 showed patchy or partial positivity. Myoepithelial markers were negative. P63 was diffusely positive, but it was negative in the small amount of tumor cells with mature characteristics. The common genetic alterations (EGFR, KRAS, BRAF V600E, HER2, and ALK) of lung cancers were not detected. However, tumor recurrence was observed in the mediastinum and esophagus 12 years after surgery. The recurrent tumor had a morphology overlapping with that of the primary tumor; however, it displayed significantly malignant characteristics. The recurrent tumor was not related to high-risk HPV. A high variant allele frequency was observed in tumor suppressor gene BRCA1, TP53, oncogene GNA11, and KIT, which were all missense mutations. Considering the bland features of the primary tumor and the fact of tumor recurrence and undisputed malignant transformation, the basaloid papillary tumor was considered a tumor with uncertain malignant potential.

Bronchial Sialadenoma Papilliferum in a 10-Year-Old Boy

Sialadenoma papilliferum (SP) is a rare salivary gland tumor mostly reported in the oral cavity. Here we describe a bronchial SP in the left upper lobe bronchus of a 10-year-old boy. At bronchoscopy, a well-circumscribed polypoid lesion protruding into the bronchial lumen was identified. The tumor was excised, but eventually, the patient had to undergo a sleeve resection after 2 recurrences. Pathology revealed a papillocystic lesion with exophytic and endophytic components. The cells lining the exophytic surface and papillary structures were columnar and squamous, and the cells lining endophytic cystic and papillary structures were cuboidal to columnar, all of which were diffusely reactive with antibodies to SOX10 protein. The presence of basal cells was demonstrated by p63 immunoreactivity. The cells failed to immunohistochemically express BRAF V600E. Fluorescence in situ hybridization analysis revealed no MAML2 or RET gene rearrangement. The patient is alive 24 years after resection with no additional recurrences. Bronchial SP needs to be recognized and distinguished from other benign and malignant salivary gland and pulmonary neoplasms so that patients can receive appropriate treatment and follow-up.

Non-small cell lung carcinoma with clear cell features: a clinicopathologic, immunohistochemical, and molecular study of 31 cases

Non-small cell lung carcinoma with predominantly clear cell features is a rare histologic presentation of lung carcinoma. We have examined 31 cases of lung carcinomas showing extensive clear cell features. The patients were 10 women and 21 men aged 47-92 years (mean: 70 years). The tumors showed a predilection for the right upper and lower lobes and measured from 0.8 to 9.5 cm (mean: 4.2 cm). By immunohistochemistry, 9 cases were typed as adenocarcinoma, 19 cases as squamous cell carcinoma, and 3 showed a "null" phenotype with complete loss of markers for adenocarcinoma or squamous cell carcinoma. Most cases that typed as adenocarcinoma showed a solid growth pattern. A subset of the solid adenocarcinoma cases showed a distinctive "pseudosquamous" morphology. Next-generation sequencing was performed in 20 cases and showed a variety of molecular alterations. The most common abnormalities were found in the TP53 gene (9 cases), FGFR gene family (8 cases), KRAS (5 cases), AKT1 (5 cases), and BRAF (3 cases). Clinical follow-up was available in 21 patients; 16/21 patients died of their tumors from 6 months to 12 years after initial diagnosis (mean: 4.2 years, median: 1.5 years). Four patients were alive and well from 4 to 27 years (mean: 11.5 years, median: 7.5 years); all were pathologic stage 1 or 2. NSCLC with clear cell features can display aggressive behavior and needs to be distinguished from various other tumors of the lung that can show clear cell morphology. The identification of targetable molecular alterations in some of these tumors may be of value for therapeutic management.

SALTT study: A retrospective analysis of 111 SAlivary gland tumors of Lung and Tracheobronchial Tree

INTRODUCTION

Primary pulmonary salivary gland-type tumours (PPSGT) are rare lung neoplasms arising from submucosal seromucinous glands in the central airway.

METHODS AND RESULTS

We retrospectively analysed the clinicopathological features of 111 PPSGTs diagnosed at our institute between 2003 and 2021. The mean age at diagnosis was 43.8 years(range 6-78 years) and a male-to-female ratio of 2:1. On imaging, 92 % of cases had centrally located tumours and 37.3 % were early stage. The histopathological types included 70 cases (63 %) of mucoepidermoid carcinoma (MEC), 31 cases (27.7 %) of adenoid cystic carcinoma (ADCC), two cases of myoepithelial carcinoma, one case each of acinic cell carcinoma (ACC), clear cell carcinoma (CCC), epithelial myoepithelial carcinoma (EMC) and 5 others [including adenocarcinoma of minor salivary gland origin(n = 3), carcinoma with sebaceous differentiation(n = 1) and poorly differentiated carcinoma of salivary gland type(n = 1)]. The size of the tumours found in the resection specimens ranged from 1 cm to 13 cm, with an average size of 4.9 cm. High-risk attributes such as lymphovascular invasion (LVI), perineural invasion (PNI), pleural involvement, positive resection margins, and nodal metastasis were identified in 15.3 %, 15.3 %, 13.6 %,15.2 % and 6.7 % of cases, respectively. These attributes were found to be more frequent in ADCC than in MEC. Surgery was the main treatment modality [68/84 (80 %) cases]. ADCC cases had more recurrence and distant metastasis than MEC cases. The 3- year overall-survival (OS) and recurrence-free survival(RFS) were better in patients with age lesser than 60 years(p-value <0.0001), low pT stage (p-value 0.00038) and lower grade of MEC(p-value-0.0067).

CONCLUSION

It is crucial to have an acquaintance with the morphologic spectrum and immunophenotypic characteristics of PPSGT to recognize them in this unusual location. In tandem, it is crucial to differentiate them from conventional primary non-small cell lung carcinoma, as the management protocols and prognostic implications differ significantly.

Pulmonary salivary gland tumor-hyalinizing clear cell carcinoma: a literature review

Primary pulmonary hyalinizing clear cell carcinoma (HCCC) is a very rare lung tumor that accounts for less than 0.09% of all primary lung tumors and has no specific epidemiology. The correct diagnosis requires imaging, laboratory, pathological, immunohistochemical, and molecular examination. The most typical feature of pulmonary HCCC is the clear cell component with clear stroma. In addition, the fusion gene EWSR1::ATF1 due to t(12;22)(q13;q12) is essential for the pathological diagnosis of pulmonary HCCC. The main treatment for pulmonary HCCC is surgery. This review focus on the pathological features, immunohistochemical examination, mutation analysis and treatment of pulmonary HCCC.

Primary pulmonary adenoid cystic carcinoma: A clinicopathological study of 64 patients

BACKGROUND

This study aimed to investigate the clinicopathological features and prognostic indicators of primary pulmonary adenoid cystic carcinoma (PACC).

METHODS

Clinical data were collected from 64 primary PACC patients and analyzed retrospectively at the Tianjin Medical University General Hospital, the West China Hospital of Sichuan University, the First Affiliated Hospital of Guangxi Medical University, and the Bishan Hospital of Chongqing Medical University from January 2003 to August 2023. The 64 patients (28 males and 36 females) were aged from 20 to 73 years, with a median age of 49 years and an average age of 49.3 years.

RESULTS

Immunohistochemical staining showed that the tumors expressed CK7, S-100 protein, CK5/6, CD117, and p63. Seven patients underwent fluorescence in situ hybridization (FISH) testing and three were found to have myeloblastosis (MYB) gene translocation. In total, 53 patients underwent surgery, among whom 31 received only surgery and 22 received both surgery and postoperative chemoradiotherapy. In addition, 10 patients received chemoradiotherapy only, while one patient underwent treatment with traditional Chinese medicine. The overall survival rates in the first, third, and fifth years were 98.4%, 95.3%, and 87.5%, respectively.

CONCLUSION

Prognostic analysis revealed that age, tumor size, lymph node metastasis status, margin status, and choice of treatment modality significantly influenced the patients' prognosis.

Recent developments in the pathology of primary pulmonary salivary gland-type tumours

Primary pulmonary salivary gland-type tumours are rare neoplasms that are thought to arise from seromucinous glands that are located in the submucosa of large airways. These neoplasms have clinical and pathologic features that are distinct from other pulmonary neoplasms. The majority of primary pulmonary salivary gland-type tumours are malignant, with the most common entities being mucoepidermoid carcinoma, adenoid cystic carcinoma, and epithelial-myoepithelial carcinoma. Less commonly seen are myoepithelial carcinoma, hyalinizing clear cell carcinoma, acinic cell carcinoma, secretory carcinoma, salivary duct carcinoma, intraductal carcinoma, and polymorphous adenocarcinoma. Benign salivary gland-type tumours of the lung include pleomorphic adenoma and sialadenoma papilliferum. Morphologic, immunophenotypic, and molecular features of these neoplasms are largely similar to salivary gland tumours elsewhere, and therefore the exclusion of metastatic disease requires clinical and radiologic correlation. However, the differential diagnostic considerations are different in the lung. The distinction of salivary gland-type tumours from their histologic mimics is important for both prognostication and treatment decisions. Overall, salivary gland type-tumours tend to have a more favourable outcome than other pulmonary carcinomas, although high-grade variants exist for many of these tumour types. Recent advances in our understanding of the spectrum of salivary gland-type tumours reported in the lung and their diversity of molecular and immunohistochemical features have helped to refine the classification of these tumours and have highlighted a few differences between salivary gland-type tumours of the lung and those primary to other sites.

Mucoepidermoid carcinoma of the lung with hemoptysis as initial symptom: A case report

BACKGROUND

Mucoepidermoid carcinoma of the lung is a rare malignant tumor, accounting for 0.1%-0.2% of all lung malignancies. It is a primary salivary gland tumor of the lung. Surgical resection is the primary treatment for pulmonary mucoepidermoid carcinoma, for which there has been no standardized treatment strategy. This article reports a case of a young woman with pulmonary mucoepidermoid carcinoma with hemoptysis as the first symptom.

CASE SUMMARY

A 24-year-old female patient presented with "4 d of hemoptysis" as the chief complaint. She had no special history and denied any smoking or drinking history. Physical examination revealed that the vital signs were stable and scattered small wet rales were heard in the left lung. After admission, the lung tumor markers were checked, and no abnormalities were found. After completing the bronchoscopy, a spherical lesion was observed at the main bronchus 1.5 cm away from the protubercle, with obvious pulsation and little blood seepage on the surface, and histopathological biopsy results showed acute and chronic inflammation. She was transferred to the Department of Thoracic Surgery for surgical treatment on the 16th day after admission. After exclusion of surgical conjunctures, the patient underwent resection of the tumor in the left main bronchus with single-pore video-assisted thoracic surgery on the 19th day after admission. The postoperative histopathological biopsy results showed mucoepidermoid carcinoma of the lung. The patient and her family refused to complete genetic testing and she was discharged from the hospital on the 8th day after surgery. During the follow-up period, the patient experienced shortness of breath after feeling active and had no special discomfort.

CONCLUSION

We have documented a case of moderately differentiated mucoepidermoid lung cancer with hemoptysis as the first symptom to improve clinicians' understanding of the disease and provide a new dimension of thinking for its future diagnosis and treatment.

Pulmonary adenoid cystic carcinoma: molecular characteristics and literature review

BACKGROUND

Pulmonary adenoid cystic carcinoma (PACC) is an exceptionally rare salivary gland-type malignant neoplasm. Because of its clinical manifestations, imaging features are not different from other types of non-small cell lung cancer, which is a diagnostic challenge for most doctors.

CONCLUSIONS

A review of the literature shows that high amounts of immunohistochemical (IHC) markers, such as CK7, CD117, P63, SMA, CK5/6, and S-100 are helpful for PACC diagnosis. Surgical resection is the main treatment of PACC, but treatment options for advanced PACC patients are limited and the research of molecular targeted drugs is ongoing in advanced cases not eligible for surgery. Currently, research on PACC targeted therapy mainly focuses on the exploration of v-myb avian myeloblastosis virus oncogene homolog (MYB) and its downstream target genes. In addition, median tumor mutation burden and PD-1/PD-L1 were lower in PACC, which may indicate poor efficacy of immunotherapy in PACC patients. This review focuses on the pathologic features, molecular characteristics, diagnosis, treatment and prognosis of PACC to establish a comprehensive understanding of PACC.

Pulmonary Salivary Gland Tumor, Mucoepidermoid Carcinoma: A Literature Review

Pulmonary mucoepidermoid carcinoma (PMEC) is the most common malignant salivary gland tumor in the lungs and accounts for 0.1-0.2% of all lung malignancies in adults. It has no specific epidemiological or clinical characteristics. Correct diagnosis requires the combined examinations of images, laboratories, pathology, and immunohistochemistry (IHC) as well as molecular characteristics. PMEC tumors are characterized by squamous, intermediate, and mucus-secreting cells. Currently, histological appearance, mitotic frequency, cellular atypia, and necrocytosis allow the classification of PMEC into low grade or high grade. Molecular changes are crucial to pathological diagnosis. The driver of PMEC seems to be the fusion protein MECT1-MAML2 that is generated from a genetic mutation in t (11; 19) (q21; p13), while other gene mutations are also reported. However, no treatment of PMEC exists so far; surgical excision is still the primary treatment, while the efficacies of chemotherapy or radiotherapy are undefined. Tyrosine kinase inhibitor (TKI) therapy and immunotherapy showed to have significant therapeutic effects but require more investigation and better understanding. This review focuses on the clinical characteristics, imaging and pathologic features, immunohistochemical examination, mutation analysis, differential diagnosis, prognosis, and treatment of PMEC.

Pulmonary Sialadenoma Papilliferum and Its Mimics: What You Need to Know

Pulmonary salivary gland-type tumors (SGT) represent a small but distinct group of primary lung neoplasms. These types of tumors originate from the submucosal bronchial glands of the tracheobronchial tree. Pulmonary SGTs differ greatly in the incidence of individual tumors from salivary gland tumors of the head and neck. Additionally, the vast majority of pulmonary SGT are malignant. Recently, pathologic diagnosis has significantly improved with the application of molecular diagnostic technologies. However, the current knowledge of benign SGTs is limited; moreover, tumor diversity and overlapping morphological features of SGT represent diagnostic challenges such as correct tumor categorization and their accurate differentiation from malignant lesions. Compounding this inherent difficulty has been the recent introduction of new variants, including sialadenoma papilliferum (SP). Pulmonary SP is very rare, with limited reports available, and most of the initial diagnoses rendered so far were incorrect, resulting in inappropriate treatment. Several cases of SP have recently been reported. This review will serve to update practicing pathologists on the morphology, immunophenotype, and molecular characteristics of SP and its mimics.

Advances in cytology of lung cancer

Cytopathology has emerged as a promising platform in precision oncology especially after the revolutionary change in our understanding of the concept of lung cancer etiopathogenesis. With increasing use of minimally invasive techniques for sample acquisition, it becomes almost mandatory to utilize precious cytology samples maximally and judiciously by appropriate triaging of the specimen and timely action of the cytopathology team. Existing patient management protocols require accurate morphologic and molecular diagnosis of the lung cancer specimens which needs knowledge about evolving techniques related to specimen procurement, updates of genomic variants of lung cancer and recently developed molecular testing platforms and algorithms which are capable enough to use even miniscule amount of diagnostic material. This review provides a brief knowledge about advances in cytology of lung cancer which are helpful for developing correct clinical management strategies.