Lung spindle cell carcinoma harbouring a constitutively active epidermal growth factor receptor mutation

Pulmonary Spindle Cell Carcinoma Mimicking Granulomatous Inflammation: A Rare Case Report and Brief Review of the Literature

Background

Pulmonary spindle cell carcinoma (PSCC), a highly malignant tumor, often exhibits cell pleomorphism, a histopathological characteristic. Owing to its extremely low incidence, atypical imaging and clinical presentations, and insufficient awareness among clinicians, PSCC is often misdiagnosed, which results in delays in treatment. Herein, we reported a rare case of PSCC that was initially misdiagnosed as granulomatous inflammation.

Case Presentation

A 66-year-old male visited a local hospital with symptoms such as cough and hemoptysis. A computed tomography (CT) scan of the chest revealed a mass in his right lung, and no mediastinal lymphadenopathy was observed. Bronchoscopy showed no major abnormalities, and the results of fine needle aspiration biopsy showed granulomatous inflammation. Even though the patient received anti-infection treatment, his symptoms did not improve markedly. After two months, a follow-up CT scan of the lung showed a noticeably enlarged mass accompanied by multiple instances of mediastinal lymphadenopathy in the upper lobe of the right lung. Consequently, he underwent a second CT-guided lung biopsy at our hospital. The pathology report indicated PSCC. Due to financial constraints, genetic testing was not performed. Given his poor overall physical condition, the patient was unable to undergo systemic chemotherapy and instead received palliative radiotherapy. The prescribed radiotherapy dose for the right upper lobe lung cancer and multiple metastatic lymph nodes was 60 Gy, administered in 30 fractions. Unfortunately, he failed to adhere to scheduled follow-ups and succumbed to the disease 6 months later, as confirmed during a telephone follow-up.

Conclusion

PSCC is a rare but highly malignant lung cancer. Multiple pathological biopsies are necessary to accurately and promptly diagnose the disease, which is crucial for early treatment intervention as well as improving patient prognosis.

Comprehensive genomic profiling of pulmonary spindle cell carcinoma using tissue and plasma samples: insights from a real-world cohort analysis

Pulmonary spindle cell carcinoma (PSCC) is a rare and aggressive non-small cell lung cancer (NSCLC) subtype with a dismal prognosis. The molecular characteristics of PSCC are largely unknown due to its rarity, which limits the diagnosis and treatment of this historically poorly characterized malignancy. We present comprehensive genomic profiling results of baseline tumor samples from 22 patients histologically diagnosed with PSCC, representing the largest cohort to date. Somatic genetic variant detection was compared between paired plasma samples and primary tumors from 13 patients within our cohort. The associations among genomic features, treatment, and prognosis were also analyzed in representative patient cases. TP53 (54.5%), TERT (36.4%), CDKN2A (27.3%), and MET (22.7%) were most frequently mutated. Notably, 81.8% of patients had actionable targets in their baseline tumors, including MET (22.7%), ERBB2 (13.6%), EGFR (9.1%), KRAS (9.1%), ALK (9.1%), and ROS1 (4.5%). The median tumor mutation burden (TMB) for PSCC tumors was 5.5 mutations per megabase (muts/Mb). TMB-high tumors (>10 muts/Mb) exhibited a significantly higher mutation frequency in genes such as KRAS, ARID2, FOXL2, and LRP1B, as well as within the DNA mismatch repair pathway. The detection rates for single nucleotide variants and structural variants were comparable between matched tumor and plasma samples, with 48.6% of genetic variants being mutually identified in both sample types. Additionally, a patient with a high mutation load and positive PD-L1 expression demonstrated a 7-month survival benefit from chemoimmunotherapy. Furthermore, a patient with an ALK-rearranged tumor achieved a remarkable 3-year progression-free survival following crizotinib treatment. Overall, our findings deepen the understanding of the complex genomic landscape of PSCC, revealing actionable targets amenable to tailored treatment of this poorly characterized malignancy.

Biological characteristics and clinical treatment of pulmonary sarcomatoid carcinoma: a narrative review

Background and Objective

Pulmonary sarcomatoid carcinoma (PSC) is a subset of non-small cell lung cancer (NSCLC) with highly malignant, aggressive, and heterogeneous features. Patients with this disease account for approximately 0.1-0.4% of lung cancer cases. The absence of comprehensive summaries on the basic biology and clinical treatments for PSC means there is limited systematic awareness and understanding of this rare disease. This paper provides an overview of the biological characteristics of PSC and systematically summarizes various treatment strategies available for patients with this disease.

Methods

For this narrative review, we have searched literature related to the basic biology and clinical treatment approaches of PSC by searching the PubMed database for articles published from July 16, 1990 to August 29, 2023. The following keywords were used: "pulmonary sarcomatoid carcinoma", "genetic mutations", "immune microenvironment", "hypoxia", "angiogenesis", "overall survival", "surgery", "radiotherapy", "chemotherapy", and "immune checkpoint inhibitors".

Key Content and Findings

Classical PSC comprises epithelial and sarcomatoid components, with most studies suggesting a common origin. PSC exhibits a higher tumor mutational burden (TMB) and mutation frequency than other types of NSCLC. The tumor microenvironment (TME) of PSC is characterized by hypoxia, hypermetabolism, elevated programmed cell death protein 1/programmed cell death-ligand 1 expression, and high immune cell infiltration. Treatment strategies for advanced PSC are mainly based on traditional NSCLC treatments, but PSC exhibits resistance to chemotherapy and radiotherapy. The advancement of genome sequencing has introduced targeted therapies as an option for mutation-positive PSC cases. Moreover, due to the characteristics of the immune microenvironment of PSC, many patients positively respond to immunotherapy, demonstrating its potential for the management of PSC.

Conclusions

Although several studies have examined and assessed the TME of PSC, these are limited in quantity and quality, presenting challenges for research into the clinical treatment strategies for PSC. With the emergence of new technologies and the advancement of clinical research, for example, savolitinib's clinical study for MET exon 14 skipping mutations positive PSC patients have shown promising outcomes, more in-depth studies on PSC are eagerly anticipated.

Preoperative CT findings and prognosis of pulmonary sarcomatoid carcinoma: comparison with conventional NSCLC of similar tumor size

BACKGROUND

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small cell lung cancer (NSCLC) but differs in terms of treatment strategies compared with conventional-NSCLC (c-NSCLC). However, preoperative CT differentiation between PSC and c-NSCLC remains a challenge. This study aimed to explore the CT findings and prognosis of PSC compared with c-NSCLC of similar tumor size.

METHODS

Clinical data and CT findings of 31 patients with PSC and 87 patients with c-NSCLC were retrospectively analyzed. Clinical data included sex, age, and smoking history. CT findings included tumor size, tumor location, calcification, vacuole/cavity, pleural invasion, mean CT value, and low-attenuation area (LAA) ratio. Kaplan‒Meier curves and log-rank tests were used for survival analysis. A Cox regression model was constructed to evaluate prognostic risk factors associated with overall survival (OS). The Spearman correlation among clinicoradiological outcomes were analyzed.

RESULTS

The mean tumor size of PSC and c-NSCLC were both 5.1 cm. The median survival times of PSC and c-NSCLC were 8 months and 34 months, respectively (P < 0.001). Calcification and vacuoles/cavities were rarely present in PSC. Pleural invasion occurred in both PSC and c-NSCLC (P = 0.285). The mean CT values of PSC and c-NSCLC on plain scan (PS), arterial phase (AP), and venous phase (VP) were 30.48 ± 1.59 vs. 36.25 ± 0.64 Hu (P = 0.002), 43.26 ± 2.96 vs. 58.71 ± 1.65 Hu (P < 0.001) and 50.26 ± 3.28 vs. 64.24 ± 1.86 Hu (P < 0.001), the AUCs were 0.685, 0.757 and 0.710, respectively. Compared to c-NSCLC, PSC had a larger LAA ratio, and the AUC was 0.802, with an optimal cutoff value of 20.6%, and the sensitivity and specificity were 0.645 and 0.862, respectively. Combined with the mean CT value and LAA ratio, AP + VP + LAA yielded the largest AUC of 0.826. The LAA ratio were not independent risk factors for PSC in this study. LAA ratio was negatively correlated with PS (r = -0.29), AP (r = -0.58), and VP (r = -0.66). LAA showed a weak positive correlation with tumor size(r = 0.27).

CONCLUSIONS

PSC has a poorer prognosis than c-NSCLC of similar tumor size. The mean CT value and LAA ratio contributes to preoperative CT differentiation of PSC and c-NSCLC.

Significant response of pulmonary sarcomatoid carcinoma with obstructive atelectasis to treatment with the PD-1 inhibitor camrelizumab combined with transbronchial cryoablation: A case report and literature review

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of non-small cell lung cancer with high malignancy and poor prognosis. Chemotherapy or radiotherapy do not usually provide satisfactory results in patients with PSC, especially in those with advanced-stage cancer. Targeted therapy and immunotherapy are more precise therapies that may be effective in the treatment of PSC; however, further research is needed. Here, we present a case of stage III PSC with obstructive atelectasis, which is more challenging and hinders treatment. Treatment with the PD-1 inhibitor camrelizumab and transbronchial cryoablation showed significant clinical efficacy. This type of combined treatment has not been reported previously for PSC. Thus, this case may provide a valuable reference for future clinical practice and research.

Pulmonary sarcomatoid carcinoma: progress, treatment and expectations

Pulmonary sarcomatoid carcinoma (PSC) is a unique, highly invasive pulmonary malignancy with a poor prognosis, representing 0.1-0.4% of all malignant lung tumors. Because of its highly aggressive character and propensity for frequent metastasis, PSC shows low response rates to traditional treatments such as chemotherapy, radiotherapy, and neoadjuvant therapy. In recent years, considerable progress has been made in gene sequencing, targeted therapies, and immunotherapies. One of the most promising treatment approaches is the selection of mono-targeted or multi-targeted drugs according to tumor gene-mutation sites, such as epidermal growth factor receptor or vascular endothelial growth factor receptor 2 (EGFR/VEGFR2), anaplastic lymphoma kinase (ALK), and others. Another approach is the activation of therapeutic anti-tumor immunity via pathways including programmed cell-death protein-1/programmed cell-death ligand-1 (PD-1/PD-L1), which has been used in individual cases. In this review, we will introduce the clinicopathologic features, molecular typing, and traditional treatments. We will also review the biological characteristics and the latest therapies for PSC. These novel therapies show promise in the management of PSC, and the outcomes of investigative trials will hopefully reveal a variety of treatment options for patients with PSC.