3D-printing aided resection of intratracheal adenoid cystic carcinoma and mediastinal mature cystic teratoma in a 26-year-old female: a case report

Pulmonary Adenoid Cystic Carcinoma Mimicking Asthma-Like Symptoms: A Case Report and Literature Review

Introduction

Pulmonary adenoid cystic carcinoma (PACC) is a rare, low-grade malignant salivary gland-type tumor characterized by a dormant onset and slow progression, often leading to misdiagnosis. Due to its rarity, limited cases have been reported in the literature. This report aimed to enhance clinicians' understanding of this infrequent disease.

Case Presentation

We present the case of a 41-year-old female patient diagnosed with PACC. Our report provides a comprehensive analysis of the patient's imaging, pathology, and treatment, with a particular focus on immunohistochemical results. Importantly, we emphasize the significance of considering foreign bodies and tumors in the bronchus when encountering asthma-like symptoms unresponsive to conventional treatments. Due to the uncertain etiology and pathophysiology of PACC, there are currently no established guidelines for chemotherapy and radiotherapy.

Conclusion

PACC predominantly manifests as bronchial lesions without significant clinical heterogeneity. Therefore, it is crucial to consider foreign bodies and tumors in the bronchus when dealing with asthma-like symptoms, especially in patients without chronic lung disease who do not respond to anti-infective, antispasmodic, and antiasthmatic treatments. Additionally, meticulous examination of lesions is essential for timely diagnosis and intervention, ultimately improving patient survival rates.

Tumor immune microenvironment and mutational analysis of tracheal adenoid cystic carcinoma

Background

Tracheal adenoid cystic carcinoma (TACC) is the second most common type of cancer in bronchial tumors with poor prognosis. Studies on the genomic profiles and tumor immune microenvironment (TIME) of TACC are still relatively rare.

Methods

Here, we performed whole-exome sequencing (WES), T cell repertoire (TCR) sequencing, and immunohistochemistry (IHC) on the resected tumors and matched peripheral blood leukocytes (PBLs) samples from 25 TACCs collected from April-2010 to Mar-2019.

Results

WES results revealed that LPAR3 and ALPI were recurrently mutated genes, with no classical lung cancer drivers in TACCs (n=8). The median tumor mutation burden (TMB) was 3.67, lower than other solid tumors. Unexpectedly, one patient showed high microsatellite instability (MSI). Recurrent copy number variations (CNVs) affected genes commonly involved in p53, cell cycle, and PI3K-Akt signaling pathways. For TCR estimators of 13 PBLs, the median clonality and Shannon index was 0.15 and 7.02, respectively. Shannon index showed marginally negative association with age (Pearson r =−0.53, P=0.062). Clonotype number and Shannon index of 7 TACC tissues were significantly lower than those of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) (Mann-Whitney test, both P<0.001, both P<0.001). Furthermore, programmed cell death 1 ligand 1 (PD-L1), a vital player in TIME, was negative (tumor proportion score, TPS <1%) in all samples (n=14). Patients with less clonotypes had longer progression-free survival (PFS) than those with more PFS (15.0 vs. 9.5 months, P<0.001, HR 12.5, 95% CI: 0.2–675.7). In particular, the clinical and molecular characteristics of one TACC patient receiving immunotherapy have been explained in detail.

Conclusions

In summary, despite the existence of one patient with MSI-H and chromosome instability, TACC was characterized by a lack of common drivers of lung cancer, negative PD-L1 expression, and low CD3+ and CD8+ T cell infiltration.