Pulmonary enteric adenocarcinoma

Cytologic Diagnoses of Lung Adenocarcinoma With Concomitant Metastasis From a Different Primary: A Case Series

Lung adenocarcinoma is a common malignancy that can metastasize. The lung is also a common site for metastasis from other sites. Prompt and accurate diagnosis is critical for patient management. The diagnosis of lung adenocarcinoma can be occasionally challenging due to overlapping clinical and pathological features with adenocarcinomas from other origins. We present three cases of lung adenocarcinomas with concomitant metastatic adenocarcinomas of different primaries in the same endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA) or core biopsy procedures. The first case showed metastatic ROS-rearranged lung adenocarcinoma and metastatic ampullary adenocarcinoma involving different mediastinal lymph nodes, respectively, in a patient with no previous history of malignancy. The second case showed metastatic lung adenocarcinoma with MET exon 14 deletion and metastatic breast adenocarcinoma involving different mediastinal lymph nodes, respectively, in a patient with a previous history of breast carcinoma. The third case showed metastatic prostatic adenocarcinoma to a pre-existing lung mucinous adenocarcinoma in a patient with a previous history of prostatic adenocarcinoma. Our report highlights attention to details, judicious use of immunostains, and ancillary molecular studies in complex pathology cases. Cytohistological findings are also correlated with molecular test results.

[Rare subtypes of lung cancer]

In Europe, a rare cancer is defined as having an incidence rate of less than 6/100,000. Rare lung cancers encompass many entities defined by the 2021 WHO classification of thoracic tumors, and represent around 10% of all lung cancers. Rare lung cancers involve several histological types (carcinoma, sarcoma and lymphoma), each of which comprises several entities. The management of these patients with rare cancers requires specific medical expertise at every level (diagnosis, treatment and follow-up). These patients should therefore be referred to expert centers affiliated with national networks, giving them appropriate care and better access to innovative treatments. The deployment of systematic molecular characterization of these tumors has allowed for the identification and better characterization of specific entities. Some entities are specific to the lung, while others are more commonly found in other organs. In this review, we will only consider malignant lung tumors with an incidence of less than 1%.

Pulmonary enteric adenocarcinoma with progression disease after second - line therapy: a case report

Pulmonary enteric adenocarcinoma (PEAC, also known as Enteric-type adenocarcinoma of the lung, lung - ETAC) is a rare subtype of non-small cell lung cancer (NSCLC) that has the same morphological and immunohistochemical characteristics as colorectal adenocarcinoma and requires gastroenteroscopy to rule out lesions of enteric origin. As a rare solid tumor in lung cancer, PEAC has unique clinical outcome, imaging, pathological and molecular characteristics, and poor prognosis. However, the molecular characteristics and therapeutic biomarkers of PEAC are unclear, and its treatment remains challenging. In this case, we describe a 61-year-old man diagnosed with advanced primary PEAC with KRAS mutation. In the case of unknown PD-L1 expression status, first-line treatment was given to lung adenocarcinoma regimen (immunotherapy combined with chemotherapy), progression occurred after 2 cycles, and progression-free survival (PFS) was 1.5 months. Then the second-line XELOX regimen (oxaliplatin combined with capecitabine) was adjusted. The lesions were significantly reduced after 2 and 4 cycles, and the disease progressed again after 6 cycles, with a PFS of 4.5 months. Anlotinib targeted drugs were selected for third-line treatment, but considering the overall poor condition of the patient, the patient himself refused further treatment. Finally, after discharge, the patient went to the local hospital for nutritional support and symptomatic treatment. The results suggest that standard first-line therapies (immunotherapy plus chemotherapy) and colorectal cancer regimens may have a relatively limited impact on survival in KRAS-driver positive advanced PEAC.

Lung enteric-type adenocarcinoma with gastric metastasis: a rare case report and literature review

Lung enteric-type adenocarcinoma (ETAC) is a rare subtype of non-small cell lung cancer (NSCLC), comprising approximately 0.6% of all primary lung adenocarcinomas. It is characterized by a tendency for early metastasis and a prognosis comparable to that of common lung adenocarcinoma. This case report described a patient with lung-ETAC who developed gastric metastasis. The patient underwent treatment with chemotherapy and a PD-1 inhibitor, resulting in disease remission with a progression-free survival (PFS) of 8 months. The follow-up time was 13 months. This case report was aimed to enhance understanding of the biological behavior of this rare tumor and provide insights into potential future treatment strategies.

Case report: Recurrence of primary hepatic neuroendocrine tumors after resection of liver segments IV in 8 years follow-up

Background

Primary hepatic neuroendocrine tumors (PHNETs) are an utterly rare entity. The diagnosis of PHNETs could legitimize when an extrahepatic primary NET must always be excluded. PHNETs can achieve a high survival rate after complete surgical resection, however, most patients still have an 18% risk of recurrence within 5 years after surgery. In our case, the recurrence occurred 8 years after the first hepatectomy, which is relatively rare in the current literature. Therefore, rigorous postoperative follow-up is necessary for early detection and timely treatment of recurrent PHNETs.

Case information

We report a case of PHNET in a 24-year-old previously healthy female patient who relapsed 8 years after hepatectomy. This case focuses on the importance of diagnosis of primary and recurrent PHNETS in young patients, rare pathological types, and post-operative follow-up.

Conclusion

This case report detailed the rare pathological morphology and characteristic immunohistochemical markers in our case for PHNETS, which enhanced the new understanding of the diagnosis of this entity. In addition, we also highlighted the variable duration of recurrence after treatment of PHNETs. The 8-year recurrent period in our case suggests the importance of regular examination in patients with PHNETs by following the doctor's instructions.

Pulmonary Adenocarcinoma with Enteric Differentiation without TTF-1 Expression Is a Very Rare Subtype with Limited Treatment Options and Poor Prognosis

INTRODUCTION

Pulmonary adenocarcinoma with enteric differentiation (PAED) without thyroid transcription factor-1 (TTF-1) expression is an extremely rare variant of lung cancer. Due to its rarity, few clinicopathological and molecular studies have been performed on PAED, particularly in Caucasian patients. Therefore, it is necessary to obtain clinicopathological data of Caucasian PAED patients without TTF-1 expression, their systemic therapy options, and the efficacy of their systemic treatment.

METHODS

We examined the clinicopathological features of 121 cases of TTF-1-negative pulmonary adenocarcinoma at a certified German lung cancer center including 79 cases without a PAED and 42 cases with a PAED, compared these subgroups, and investigated patients' response to chemotherapy and immunotherapy as first-line treatment. By using endoscopy and/or a PET-CT, a primary adenocarcinoma of the digestive tract was excluded in all PAED patients.

RESULTS

A comparison of clinicopathological data of TTF-1-negative PAED and non-PAED patients revealed a significantly lower frequency of high programmed death receptor ligand 1 (PD-L1) expression in PAED resulting in the lack of single-agent immunotherapy (p = 0.032) in this subgroup. Frequencies of an activating Kirsten rat sarcoma viral oncogene homolog (KRAS) gene mutation were high in both groups (46.7% and 50.0%), but G12C gene mutations were seldomly noted (in 6.7% and 18.5% of patients with evaluable data). Median overall survival (OS) was poor in both groups (10 and 12 months). The majority of PAED patients received platinum-based and taxane-containing chemotherapy or chemo-/immunotherapy with an objective response rate (ORR) of 31.6% and a disease control rate of 57.9%. Median progression-free survival (PFS) and OS of PAED patients with systemic therapy were very poor (3.9 months and 5.9 months).

CONCLUSIONS

Caucasian patients with TTF-1 negative PAED have a poor prognosis with a reduced ORR to standard first-line systemic therapy and short survival times (PFS and OS).

Case report: Pathological complete response of pregnancy associated pulmonary enteric adenocarcinoma to chemoradiotherapy

Pulmonary enteric adenocarcinoma (PEAC) is a rare lung adenocarcinoma with morphological features similar to those of primary and metastatic colorectal adenocarcinoma. To date, only a few studies have reported the therapeutic effects of chemoradiotherapy on PEAC. This report describes the case of a 28-year-old woman with pregnancy-related PEAC who presented with left shoulder pain. A superior sulcus tumor was identified in the left thoracic cavity, and the biopsy indicated more than 50% intestinal differentiation components. Moreover, immunohistochemical staining revealed positive CDX2 and CK7 expression. Positron emission tomography-computed tomography, upper endoscopy, colonoscopy, and small intestinal capsule endoscopy revealed no gastrointestinal malignancies. The patient was diagnosed with locally advanced PEAC (clinical stage T4N0M0; stage IIIA). Therefore, the patient was treated with preoperative chemoradiotherapy and underwent gross total resection during surgery. Pathological evaluation of the specimen revealed no residual tumor, indicating that the chemoradiotherapy for PEAC was highly effective. One subsequent brain metastasis was also resected, and the patient has not experienced recurrence in 28 months since this resection and continues to be monitored regularly. This is the first pathologically confirmed report of the use of chemoradiotherapy (carboplatin [CBDCA] and paclitaxel [PTX]) for PEAC and its clinical efficacy. Unlike previous reports, the efficacy of this treatment is attributed to the use of PTX in preoperative chemotherapy and the p21- status of the patient, which may have increased sensitivity to chemoradiation therapy. Therefore, chemoradiotherapy (CBDCA + PTX) may be a viable treatment option for advanced intestinal lung adenocarcinoma.

Case report: Target and immunotherapy of a lung adenocarcinoma with enteric differentiation, EGFR mutation, and high microsatellite instability

Background

Pulmonary enteric adenocarcinoma (PEAC) is a rare histological subtype of non-small-cell lung cancer (NSCLC) with a predominant (>50%) enteric differentiation component. The frequency of high microsatellite instability (MSI-H) is very low in lung cancer. EGFR tyrosine kinase inhibitors and immunotherapy are standard treatment for NSCLC patients, but their effectiveness in lung adenocarcinoma with pulmonary enteric differentiation is unknown.

Case presentation

This report describes a 66-year-old man who was initially diagnosed with metastatic lung adenocarcinoma with EGFR mutation based on pleural fluid. A lung biopsy was obtained after 17 months of first-line icotinib treatment. Histological analysis of biopsy samples and endoscopic examination resulted in a diagnosis of adenocarcinoma with enteric differentiation. Next-generation sequencing of 1,021 genes showed EGFR E19del, T790M, and MSI-H, while immunohistochemical assay showed proficient expression of mismatch repair (MMR) proteins. Consequently, the patient was treated with osimertinib and had a progression-free survival (PFS) of 3 months. His treatment was changed to chemotherapy with/without bevacizumab for 6.5 months. Then, the patient was treated with one cycle of camrelizumab monotherapy and camrelizumab plus chemotherapy, respectively. The tumor continued to grow, and the patient suffered pneumonia, pulmonary fungal infections, and increased hemoptysis. He received gefitinib and everolimus and died 2 months later and had an overall survival of 30 months.

Conclusion

In summary, our case describes a rare pulmonary enteric adenocarcinoma with an EGFR-activating mutation and MSI-H, responding to an EGFR tyrosine kinase inhibitor and poorly benefiting from an immune checkpoint inhibitor.

Primary pulmonary enteric adenocarcinoma presenting as a solitary skull mass

Pulmonary enteric adenocarcinoma (PEAC) is a rare, aggressive variant of lung adenocarcinoma with early metastatic potential. We present the case of a male smoker in his 50s who presented with right-sided numbness, pain and headache. Imaging revealed a destructive skull base mass invading the right sphenoid sinus. Histopathology was consistent with PEAC. The diagnosis was metastatic PEAC with a distant spread to the skull and represents the first case reported in the literature. We present an associated literature review of the clinical presentation, histological features and management of PEAC with skull metastasis. Metastasis should be considered when evaluating any persistent cranial lesion. Diagnosis requires thorough clinical, radiological and pathological assessment. Treatment involves surgical resection, chemoradiation and targeted therapy. Prognosis directly correlates with clinical stage at presentation. This case highlights the importance of careful evaluation of skull lesions, even in patients without known primary malignancy. Early diagnosis and multimodal therapy may improve outcomes.

Clinicopathological and genetic analyses of pulmonary enteric adenocarcinoma

AIMS

Pulmonary enteric adenocarcinoma (PEAC) is a rare variant of pulmonary adenocarcinoma. Due to its rarity, few pathological and molecular studies have been performed on PEAC. We herein conducted clinicopathological, immunohistochemical and molecular analyses of PEAC with a focus on its differentiation from invasive mucinous adenocarcinoma (IMA).

METHODS

We examined the clinicopathological features of 16 cases of PEAC and performed a genetic analysis using next-generation sequencing (NGS). The results obtained were compared with those for IMA.

RESULTS

The average age of patients with PEAC (seven men and nine women) was 72.9 years. A comparison of clinical data on PEAC and IMA revealed no significant differences in age, sex or smoking history. Fifteen PEAC cases had dirty necrosis. Immunohistochemically, the positive rates for each antibody in PEAC were as follows: CK7, 88% (14/16); CK20, 81% (13/16); CDX2, 88% (14/16); p53, 69% (11/16); MUC1, 100% (16/16); MUC2, 19% (3/16); MUC5AC, 69% (11/16); MUC6, 19% (3/16). The positive rates for these antibodies in IMA were 100%, 87%, 0%, 7%, 93%, 0%, 100% and 80%, respectively. EGFR mutations, the MET exon 14 skipping mutation, BRAF mutations, the ALK fusion gene and ROS-1 fusion gene were not detected in any cases of PEAC or IMA. Among PEAC cases, NGS identified KRAS mutations in seven (44%, 7/16) and TP53 mutations in nine (56%, 9/16). Among IMA cases, the most commonly mutated gene was KRAS (90%).

CONCLUSIONS

The rates of dirty necrosis, immunopositivity for CDX2 and TP53 mutations were significantly higher, while that of KRAS mutations was significantly lower in PEAC cases than in IMA cases.

Exceptional Response in BRAF p.V600E-Mutant Enteric-Type Adenocarcinoma of the Lung With Cutaneous Spread: A Case Report

Background

Enteric-type adenocarcinoma of the lung (lung-ETAC) is a rare form of lung cancer with histologic similarities to colorectal cancer, with aggressive behavior and unfavorable prognosis.

Case Presentation

An 81-year-old man presented with discolored skin lesions on the chest and abdomen. After comprehensive evaluation, including skin biopsy and molecular profiling, the patient was diagnosed with having lung-ETAC with a BRAF p.V600E mutation. Treatment with dabrafenib and trametinib initially resulted in positive results, with improvement in skin lesions and overall clinical condition. Nevertheless, approximately 6 months after, the disease had progression with new skin lesions reappearing.

Conclusions

We reported a unique case of a patient with BRAF p.V600E-mutant lung-ETAC with metastatic skin lesions achieving complete cutaneous response after targeted treatment with dabrafenib and trametinib, highlighting the potential for targeted therapy in patients with lung-ETAC harboring a BRAF p.V600E mutation.

Gefitinib, an effective treatment option for patients with pulmonary enteric adenocarcinoma harboring compound EGFR L858R and A871G mutation

Pulmonary enteric adenocarcinoma (PEAC) is a rare lung adenocarcinoma with morphological and immunohistochemical similarities to colorectal adenocarcinoma and intestinal differentiation. PEAC belongs to the group of non-small-cell lung carcinoma (NSCLC) and is defined as having a more than 50% intestinal differentiation component. We report a postoperative (T4N2M0 stage IIIb) PEAC patient with EGFR L858R + A871G combined mutation. Following surgery, the patient underwent treatment with the first-generation EGFR-TKI, gefitinib, and achieved an impressive 5-year progression-free survival (PFS). This suggests that gefitinib may serve as an effective treatment option for PEAC patients with EGFR L858R + A871G compound mutations.

Frequent nuclear β-catenin expression in pulmonary enteric-type adenocarcinoma according to the current World Health Organization criteria

Based on the current World Health Organization classification criteria, five of 3895 consecutive cases of surgically resected primary lung carcinomas (0.13%) categorized as enteric-type were analyzed. Three cases completely comprised tumor cells that resemble colorectal adenocarcinoma, while the other two cases exhibited features of conventional adenocarcinomas admixed with enteric components. Immunohistochemically, all patients expressed at least three of the five intestinal markers: CDX2, CK20, HNF4α, MUC2, and SATB2. None of the patients expressed TTF-1 and NKX3.1. Three cases showed nuclear accumulation of β-catenin, indicating activation of the Wnt/β-catenin signaling pathway; APC mutations were detected in one of these cases. TP53 mutations were detected in three cases. Mutated EGFR or ALK fusions were not detected. Our study demonstrates that pulmonary enteric-type adenocarcinomas share immunohistochemical features and genetic alterations with colorectal adenocarcinomas, which are characterized by frequent activation of the Wnt/β-catenin signaling pathway and a lack of actionable mutations.

Lymph node and bone metastasis of pulmonary intestinal adenocarcinoma: A case report

Pulmonary enteric adenocarcinoma (PEAC) is a rare pathological type of lung adenocarcinoma, accounting for ~0.6% of primary lung adenocarcinoma, which has similar morphological and immunohistochemical characteristics to colorectal adenocarcinoma. Making a certain differential diagnosis of PEAC based on morphological and immunohistochemical results is difficult. It is known that PEAC may metastasize to the pancreas, skin, soleus muscle and intestine, but no bone metastasis has been reported. At our department, a rare case of PEAC with bone and lymph node metastasis was previously diagnosed. The present case study reports on a 58-year-old male patient encountered at our hospital with pain in the lumbar, back and right iliac with no obvious cause. Chest CT indicated a space-occupying lesion in the left upper lung lobe, enlarged lymph nodes in the mediastinum and left lung, and partial vertebral bone destruction. Enhanced CT results indicated multiple foci of active bone metabolism in the body, while rectal colonoscopy showed no obvious abnormalities. Histopathological and immunohistochemical results after right iliac bone puncture suggested stage IV PEAC with secondary malignancies in bones, mediastinal lymph node, hilar lymph node and left supraclavicular lymph node.

Deciphering Lung Adenocarcinoma Heterogeneity: An Overview of Pathological and Clinical Features of Rare Subtypes

Lung cancer is one of the most frequently diagnosed cancers worldwide and the leading cause of cancer-related death. The 2021 World Health Organization (WHO) classification provided a detailed and updated categorization of lung adenocarcinomas with a special focus on rare histological types, including enteric, fetal and colloid types, as well as not otherwise specified adenocarcinoma, overall accounting for about 5-10% of all cases. However, rare entities are nowadays difficult to diagnose in most centers, and evidence of optimal therapeutic management for these patients is still lacking. In recent years, increasing knowledge about the mutational profile of lung cancer, in addition to the spreading diffusion of next-generation sequencing (NGS) in different centers, have been helpful in the identification of rare variants of lung cancer. Hence, the hope is that several new drugs will be available in the near future to treat these rare lung tumors, such as in targeted therapy and immunotherapy, which are often used in clinical practice for several malignancies. The aim of this review is to summarize the current knowledge about the molecular pathology and clinical management of the most common rare adenocarcinoma subtypes in order to provide a concise and updated report that can drive clinicians' choices in their routine practice.

Clinical presentation and outcome of patients with enteric-type adenocarcinoma of the lung: A pooled analysis of published cases

Enteric-type adenocarcinoma of the lung (lung-ETAC, former pulmonary enteric adenocarcinoma, PEAC) is a rare subtype of non-small cell lung cancer (NSCLC), which shares morphological and immunohistochemical features with lung and colorectal adenocarcinoma. Few data are available on patient prognosis, possible prognostic factors and systemic approach to metastatic disease. We performed a pooled analysis and a systematic review of published lung-ETAC, along with an additional case description. Thirty-one eligible publications were identified, providing data from 126 patients. In the 127 patients overall analyzed, median overall survival (OS) was 56.0 (range 36.7-75.3) months in early-stage patients and 14.0 (range 4.5-23.5) months in those with advanced/metastatic disease. Median disease-free survival (DFS) after radical surgery was 24 (range 22.6-35.1) months. Smoking status (HR 4.304, 95% CI: 1.261-14.693, p = 0.020) and node involvement (HR 1.853, 95% CI: 1.179-2.911, p = 0.007) were the negative independent prognostic factors at multivariate analysis. As regards systemic therapies for advanced cases, no firm conclusions were drawn about the efficacy of lung cancer-oriented chemotherapy regimens as opposed to colon cancer-oriented ones. Molecular analysis of lung-ETAC revealed a relatively high mutational rate, with alterations in several druggable molecular pathways, KRAS and NRAS (31%) were the most frequently mutated oncogenes, followed by ROS1 (15%), RET (13%), BRAF (11%), EGFR (8%) and ALK (6%). Moreover, 3 (15%) out of 20 cases showed DNA mismatch repair deficiency (dMMR). In conclusion, advanced lung-ETAC patients appeared to have a better prognosis compared to other subtypes of NSCLC. Moreover, the mutational rate and microsatellite instability found in lung-ETACs suggest that a significant proportion of these patients could benefit from target therapies and immunotherapy.

Clinical features and prognosis of pulmonary enteric adenocarcinoma: A retrospective study in China and the SEER database

Objective

Pulmonary enteric adenocarcinoma (PEAC) is a rare subtype of pulmonary adenocarcinoma that lacks effective treatment. The purpose of this research was to investigate the clinical characteristics, treatment, and prognosis of PEAC, as well as the impact of relevant factors on survival, thus providing a reference for the clinical management of patients with this disease.

Methods

For this study, we gathered clinical data from 26 patients with PEAC in the Affiliated Cancer Hospital of Zhengzhou University from June 2014 to June 2021. We used SEER*Stat software V8.3.5 to download the PEAC patients from the Surveillance, Epidemiology, and End Results (SEER) database. In total, 20 patients were identified. Clinical data, including general information, imaging findings, and treatment protocols, were obtained, together with a follow-up of disease regression. The relevant clinical data were then analyzed.

Results

It included 12 males and 14 females out of 26 patients from China, whose mean age was (62.73 ± 11.89) years; 20 were in the lower lung, 11 were stage I-II, and 15 were stage III-IV. Five had EGFR mutations, and four had KRAS mutations. In terms of treatment, patients with stage I-II were primarily treated by surgery, and patients with stage III-IV were treated mostly by chemotherapy. We extended the follow-up date to January 2022. On completion of the follow-up visit, 11 patients died, and the remaining 15 patients survived. The overall survival (OS) of 26 patients was 2.0-76.0 months, while the mean was 53.1 months, and the median OS (mOS) was 38.0 months (95% CI:1.727-74.273). In the case of progression-free survival (PFS) times, it was 2.0-76.0 months, with a mean PFS of 31.0 months and a median PFS (mPFS) of 8.0 months (95% CI:4.333-11.667). The PFS of the 15 patients in stage III-IV was 2.0-17 months, while the mean PFS was 6.5 months and the mPFS was 6.0 months (95% CI:4.512-7.488). Out of the 20 patients identified in the SEER database, the average age was 69.9 years, with 14 males and 6 females. Of these patients, 8 were diagnosed with stage I-II, while the remaining 11 were diagnosed with stage III-IV. 10 underwent surgery, 4 received radiation therapy, and 9 received chemotherapy. The mean OS of the 20 patients was 67.5 months, mOS was 28.0 months (95% CI: 9.664- 46.336). For patients diagnosed with stage III-IV, the mean OS was 14.8 months and mOS was 20 months (95% CI: 4.713-35.287).

Conclusion

PEAC is rare, and the prognosis is determined mainly by the stage; patients who undergo surgery in stage I-II have a better prognosis.

Hyperprogressive Disease After Immunotherapy: A Case Report of Pulmonary Enteric Adenocarcinoma

Primary pulmonary enteric adenocarcinoma (PEAC) is a rare invasive adenocarcinoma clinically similar to metastatic colorectal adenocarcinoma (MCRC). Although many studies have addressed the differential diagnosis of PEAC, few have described the treatment of PEAC, especially using immunotherapy. This report describes a 61-year-old man who presented initially with pain in the ribs. Pathological analysis of biopsy samples shows malignant tumors of the right pleura, and next-generation sequencing of 26 genes showed a KRAS gene mutation. Positron emission tomography-computed tomography (PET-CT) found no evidence of gastrointestinal malignancy. Due to multiple metastases, the patient could not undergo radical surgery. The patient was treated with a combination chemotherapy regimen of paclitaxel plus carboplatin, along with sindilizumab immunotherapy, but, after one cycle of treatment, the tumor showed a hyperprogressive state. The patient is still being monitored regularly. These findings indicate that chemotherapy combined with immunotherapy may be ineffective in the treatment of primary PEAC with positive driver genes.