Pulmonary mucinous adenocarcinoma: An overview of pathophysiology and advancements in treatment.

Pulmonary mucinous adenocarcinoma (PMA), a distinct subtype of non-small cell lung cancer (NSCLC), is characterized by an abundance of mucin-producing cells. Although this subtype comprises a relatively small fraction of lung adenocarcinomas, PMA stands apart due to its unique clinical, pathological, and molecular features. This review comprehensively discusses the pathophysiology and etiology, clinical features, diagnostic methods, treatment strategies, prognosis, and future directions for PMA, drawing from relevant literature and existing studies. Advances in PMA treatment includes surgical intervention, targeted therapy, immunotherapy, and adjuvant therapy. Particularly, we discussed factors influencing the prognosis of PMAs, such as molecular markers, pathological features, and the impact of the latest treatment advances on prognosis. Moreover, we intended this review to be a comprehensive reference for diagnosing, treating, and assessing the prognosis of PMA, providing valuable guidance for clinical practice.

Gallium-68-Labeled Fibroblast Activation Protein Inhibitor as an Alternative Radiotracer to Fluorine 18-Fluorodeoxyglucose: A Case Report of Rare Pulmonary Colloid Adenocarcinoma Diagnosed by PET/CT.

Colloid pulmonary adenocarcinoma represents a seldom encountered neoplasm in clinical practice. The diagnostic process for this rare neoplasm is complicated by its infrequency and the limited understanding of its specific molecular imaging characteristics. We report a 65-year-old male who was diagnosed with pulmonary colloid mucinous cystadenocarcinoma. Fluorine 18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) was conducted for initial evaluation. The scan showed mild 18F-FDG expression at the primary tumor site, and several non-18F-FDG-avid mediastinal and paraesophageal lymph nodes exhibited suspicious morphologic features. Owing to the ongoing atrial fibrillation, initial histopathological confirmation of the primary tumor mass carries a sense of risk, prompting the imperative for cardiological assessment before proceeding. Instead, Gallium-68-labeled fibroblast activation protein inhibitor (68Ga-FAPI) PET/CT was performed, expecting this to be more informative in terms of malignancy potential than 18F-FDG PET in colloid mucinous histology. A scan revealed moderate 68Ga-FAPI expression at the primary tumor site but unremarkable 68Ga-FAPI expression at the questionable lymph node. Subsequently, a biopsy from a mediastinal node (left para-aortic) lymph node via endobronchial ultrasound (EUS) showed benign findings. The patient was treated with concurrent chemoradiation. This case underscores the vital role that 68Ga-FAPI PET/CT can play in specific cases of rare cancers, especially when invasive testing for tissue biopsy is not feasible.

[Pulmonary Mucinous Adenocarcinoma Combined with Bronchial Squamous Cell 
Papilloma and Infection with Tropheryma Whipplei: A Case Report].

Simultaneous multiple primary tumors on the same side of the lung with Tropheryma whipplei (TW) infection are rare. We reviewed the clinical data, imaging manifestations, pathological results, diagnosis and treatment of a primary pulmonary mucinous adenocarcinoma (PPMA) patient with bronchial squamous cell papilloma (BSCP) and TW infection, and discussed our treatment experience. The patient mainly presented with chronic cough and sputum, and computed tomography (CT) showed inflammatory changes with multiple nodular shadows. Biopsy of the lower lobe of the right lung showed PPMA, and right lung sub-branchial nodules discovered during bronchoscope revealed BSCP. Metagenomics next generation sequencing (mNGS) of bronchoalveolar lavage fluid showed mixed infection of Streptococcus pneumoniae and TW with a poor anti-infective effect. No clear genetic mutation was detected, and the patient was treated with chemotherapy and regularly followed up. We should improve the awareness of multiple pulmonary pathologies during clinical practice, avoid missed diagnosis and misdiagnosis, and carry out comprehensive treatment after clarifying the diagnosis as soon as possible.
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Clinical status and research progress of primary pulmonary mucinous adenocarcinoma / 中国综合临床

Primary pulmonary mucinous adenocarcinoma is a subtype of lung adenocarcinoma, and its epidemiology is similar to other pulmonary adenocarcinoma. Because of its low incidence rate, the survival data of patients with pulmonary mucinous adenocarcinoma are few and often contradictory. KRAS mutations often occur in pulmonary mucinous adenocarcinoma, but EGFR mutations are rare. The expression of PD-L1 in pulmonary mucinous adenocarcinoma is very low. Patients with early pulmonary mucinous adenocarcinoma can benefit from surgery. Lobectomy is still the standard operation at present, but sub lobectomy may also be effective for early pulmonary mucinous adenocarcinoma. Other treatment options include platinum based dual drug chemotherapy, targeted therapy targeting driving genes, and the recent rise of immunotherapy. Future new targets and corresponding treatments should require more research to confirm.

Interpretation of CT images of pulmonary mucinous adenocarcinoma / 中国综合临床

Pulmonary mucinous adenocarcinoma (PMA) is relatively rare. On chest CT, it can be divided into two types: mass type and pneumonia type. Mass type PMA is more common and is difficult to distinguish from other nonsmall cell lung cancer. It is a solid or partial solid nodule or mass, predominantly located in the peripheral field of the lung with lobulation, spiculation, and more prone “vacuole sign”. Pneumonia type PMA has a poor prognosis and is more likely to develop into diffuse, multifocal and multilobular lesions similar to inflammatory manifestations, indicating dissemination along the airway. Typical signs include large areas of low density, low enhancement consolidation, and “dead tree sign”.

Prospect on medical treatment of pulmonary mucinous adenocarcinoma / 中国综合临床

Pulmonary mucinous adenocarcinoma is a subtype of lung adenocarcinoma, among which invasive mucinous adenocarcinoma (IMA) is the most common subtype and is easily misdiagnosed as pneumonia. Its etiology and pathogenesis are unclear and may be related to gene mutations and other factors. Due to its relative rarity and few related studies, guidelines do not provide advices on its treatment. KRAS mutations are common in IMA patients, and Sotorasib may be effective against KRAS G12C mutated IMA. NRG1 fusion is considered to be an important driver of IMA, and afatinib may be effective in treating IMA with NRG1 fusion/rearrangement. PD-L1 expression is very low in IMA patients, while B7-H3 expression is high, so B7-H3 may be a potential immunotherapeutic target.

Pulmonary invasive mucinous adenocarcinoma mimicking pulmonary actinomycosis.

BACKGROUND: Primary pulmonary invasive mucinous adenocarcinoma is a rare and distinct subtype of lung adenocarcinoma. CASE PRESENTATION: A 72-year-old woman presented with productive cough for two months and fever for six days. Chest computed tomography (CT) showed a mass in the left lower lobe. Sputum culture tested negative for bacteria, but the sequence of Actinomyces meyeri was detected by metagenomic next generation sequencing from the bronchoalveolar lavage fluid. It was considered a pathogenic bacterium as the normalized number of DNA sequencing reads was 10 times higher than the normal level. The patient's symptoms alleviated quickly, and the chest CT lesion shrank to a third of the original size following treatment with penicillin for two months. However, a repeat chest CT performed after four months of treatment revealed that the lesion had expanded. Positron emission tomography/CT revealed that fluorodeoxyglucose metabolism was increased in the mass with surrounding ground glass density of the left lower lobe. Furthermore, CT-guided percutaneous lung biopsy was performed, and hematoxylin-eosin staining showed columnar tumor cells with abundant mucin in the cytoplasm with a basal nucleus. Finally, the patient was diagnosed with pulmonary invasive mucinous adenocarcinoma and agreed to undergo a thoracoscopic surgery. CONCLUSIONS: Pulmonary invasive mucinous adenocarcinoma is a subset of lung adenocarcinoma with low incidence rate. The clinical features and CT findings are non-specific. A histopathological diagnosis is of fundamental importance in preventing misdiagnosis.

Chemotherapy in combination with pembrolizumab and antiangiogenesis in young patients with advanced primary pulmonary mucinous adenocarcinoma: Two case reports.

Primary pulmonary mucinous adenocarcinoma is an unusual histological type of non-small cell lung cancer and has a rare prevalence at a young age. There is no standard first-line therapy for advanced primary pulmonary mucinous adenocarcinoma in children and young adults-this study reports two rare cases of primary pulmonary mucinous adenocarcinoma with wild-type anaplastic lymphoma kinase and epidermal growth factor receptor (EGFR) genes. One is a 13-year-old boy (Case#1), and another is a 27-year-old male (Case#2). Both two cases were treated with antibiotics for suspected pulmonary infection. In our hospital, they were diagnosed with advanced primary pulmonary mucinous adenocarcinoma, the Eastern Cooperative Oncology Group (ECGO) performance status was three scores. We chose pembrolizumab and chemotherapy plus angiogenesis inhibitors for Case#1 and Case#2. The two patients' symptoms improved and presented with a partial response according to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 criteria，the scores of ECOG performance status were two for Case#1 and one for Case#2. This study illustrates a promising outcome for advanced primary pulmonary mucinous adenocarcinoma with immunotherapy and chemotherapy plus angiogenesis inhibitors at a young age.

Pulmonary mucinous adenocarcinoma in the presence of reactivated tuberculosis: A case report.

We report the case of a 55-year-old male patient with concomitant pulmonary mucinous adenocarcinoma and reactivated tuberculosis, documented with multiple MSCT (multi-slice computed tomography) changes. The patient initially presented with productive cough, sluggishness, fatigue, voice hoarseness and tuberculosis changes in MSCT. Later, he was diagnosed with pulmonary mucinous adenocarcinoma, which was confirmed by sputum cytology and transthoracic biopsy. Therefore, clinicians should always evaluate the likelihood of simultaneous lung cancer in patients whose MSCT images suggest TB alterations in the lungs, and swiftly decide on the correct treatment and management approach.

18F-FDG PET/CT imaging on a case of primary pulmonary mucinous adenocarcinoma / 天津医药

Primary pulmonary mucinous adenocarcinoma (PPMA) is a low incidence subtype of lung adenocarcinoma. Clinical data of a case with PPMA confirmed pathologically were retrospectively analyzed. The case of PPMA was found the primary lesion and lymph node and bone metastases by 18F-FDG PET/CT examination on May 2017 in People's Liberation Army No. 254 Hospital. We discussed the clinical application of PET/CT in the diagnosis, staging and efficacy evaluation of PPMA.

The research progress of primary pulmonary mucinous adenocarcinoma / 实用肿瘤学杂志

Primary pulmonary mucinous adenocarcinoma with a low incidence,a subtype of lung adeno-carcinoma,occurs in adult males because of its no significant clinical specificity,likely to cause misdiagnosis,and patients with adverse prognosis.Thus,we need further to understand this disease and early diagnosis through a va-riety of methods as soon as possible.Surgical treatment is still the preferred mode of this disease.With addition to resecting lesions,it is also further pathological diagnosis,gene testing,tumor staging and prognosis as well as prep-aration for following-up chemotherapy.In recent years,with the continuous development of genetic technology and innovation,the occurrence of this disease has been found to be related to KRAS gene mutation,ALK gene re-arrangement and its related signal pathway.Related gene mutations and signaling pathways can serve as a target for the treatment of this disease,which provides a variety of ideas for the development of new targeted drugs.How-ever,there are still many problems that need further study,including standard chemotherapy for primary pulmona-ry mucinous adenocarcinoma,drug resistance to targeted drugs, and the development of new KRAS inhibitors.This article reviews the definition of primary pulmonary mucinous adenocarcinoma and pathogenesis,diagnosis and some of the latest treatment methods.

The research progress of primary pulmonary mucinous adenocarcinoma / 实用肿瘤学杂志

Primary pulmonary mucinous adenocarcinoma with a low incidence,a subtype of lung adeno-carcinoma,occurs in adult males because of its no significant clinical specificity,likely to cause misdiagnosis,and patients with adverse prognosis.Thus,we need further to understand this disease and early diagnosis through a va-riety of methods as soon as possible.Surgical treatment is still the preferred mode of this disease.With addition to resecting lesions,it is also further pathological diagnosis,gene testing,tumor staging and prognosis as well as prep-aration for following-up chemotherapy.In recent years,with the continuous development of genetic technology and innovation,the occurrence of this disease has been found to be related to KRAS gene mutation,ALK gene re-arrangement and its related signal pathway.Related gene mutations and signaling pathways can serve as a target for the treatment of this disease,which provides a variety of ideas for the development of new targeted drugs.How-ever,there are still many problems that need further study,including standard chemotherapy for primary pulmona-ry mucinous adenocarcinoma,drug resistance to targeted drugs, and the development of new KRAS inhibitors.This article reviews the definition of primary pulmonary mucinous adenocarcinoma and pathogenesis,diagnosis and some of the latest treatment methods.