Multiple regression analysis of risk factors related to radiation pneumonitis

BACKGROUND Radiation pneumonitis(RP)is a severe complication of thoracic radiotherapy that may lead to dyspnea and lung fibrosis,and negatively affects patients’quality of life.AIM To carry out multiple regression analysis on the influencing factors of radiation pneumonitis.METHODS Records of 234 patients receiving chest radiotherapy in Huzhou Central Hospital(Huzhou,Zhejiang Province,China)from January 2018 to February 2021,and the patients were divided into either a study group or a control group based on the presence of radiation pneumonitis or not.Among them,93 patients with radiation pneumonitis were included in the study group and 141 without radiation pneumonitis were included in the control group.General characteristics,and radiation and imaging examination data of the two groups were collected and compared.Due to the statistical significance observed,multiple regression analysis was performed on age,tumor type,chemotherapy history,forced vital capacity(FVC),forced expiratory volume in the first second(FEV1),carbon monoxide diffusion volume(DLCO),FEV1/FVC ratio,planned target area(PTV),mean lung dose(MLD),total number of radiation fields,percentage of lung tissue in total lung volume(vdose),probability of normal tissue complications(NTCP),and other factors.RESULTS The proportions of patients aged≥60 years and those with the diagnosis of lung cancer and a history of chemotherapy in the study group were higher than those in the control group(P<0.05);FEV1,DLCO,and FEV1/FVC ratio in the study group were lower than those in the control group(P<0.05),while PTV,MLD,total field number,vdose,and NTCP were higher than in the control group(P<0.05).Logistic regression analysis showed that age,lung cancer diagnosis,chemotherapy history,FEV1,FEV1/FVC ratio,PTV,MLD,total number of radiation fields,vdose,and NTCP were risk factors for radiation pneumonitis.CONCLUSION We have identified patient age,type of lung cancer,history of chemotherapy,lung function,and radiotherapy parameters as risk factors for radiation pneumonitis.Comprehensive evaluation and examination should be carried out before radiotherapy to effectively prevent radiation pneumonitis.

Acute respiratory distress syndrome and severe pneumonitis after atezolizumab plus bevacizumab for hepatocellular carcinoma treatment:A case report

BACKGROUND Hepatocellular carcinoma(HCC)is one of the most common cancers worldwide and has a high mortality.However,the treatment options for advanced HCC are limited to tyrosine kinase inhibitors,such as sorafenib and lenvatinib.Since previous regimens have an insufficient efficacy,the combination therapy of atezolizumab and bevacizumab(Ate/Bev)has been investigated,which showed an improvement in progression-free and overall survival.However,the adverse events of this combination therapy in advanced HCC have not been established.Herein,we report a novel case of an unresectable HCC and acute respiratory distress syndrome(ARDS)after a combination therapy of Ate/Bev.CASE SUMMARY An 82-year-old male visited our outpatient clinic for an incidentally detected liver mass.Liver magnetic resonance imaging and enhanced chest computed tomography(CT)were performed,which showed arterial hyperenhancement with washout in delayed phase suggesting HCC,and a well-defined metastatic solid nodule,respectively.F-18 fluorodeoxyglucose positron emission tomography(PET)-CT exhibited multiple hypermetabolic lesions in the iliac bone,lumbar vertebrae,and femur.Because of the high burden of the intrahepatic tumor,transarterial radioembolization was initially performed;after 37 d,a combination therapy of Ate/Bev was administered.The patient visited the emergency department three days after Ate/Bev treatment complaining of dyspnea.He was diagnosed with severe pneumonitis based on CT.Despite administering oxygen via a high-flow nasal cannula,the P/F ratio was only 74;therefore,the patient was diagnosed with ARDS based on the overall examination results.Low tidal volume with high positive end-expiratory pressure,sedative agents combined with a neuromuscular blocker,and a systemic steroid were promptly applied to manage the ARDS.However,the patient did not recover from the hypoxia and expired 31 h after being admitted.CONCLUSION Clinicians should be aware of severe pneumonitis due to the immune-related adverse events of this combination therapy,and patients should be closely monitored after therapy.

The Beneficial Effect of 3-Month-Induction Therapy with Corticosteroids and Mycophenolate Mofetil Followed by Maintenance Therapy with Yearly Rituximab Infusions as Sole Maintenance Therapy in Cryptogenic Chronic Hypersensitivity Pneumonitis

Background: The available data on cryptogenic chronic hypersensitivity pneumonitis (ccHP) indicate an inherited predisposition to disease with triggering autoimmune phenomena. Hence, we evaluated prospectively the role of a new autoimmune regimen in treatment of its severe and progressive disease. Patients and Methods: A total of 9 patients were included in the study. They had criteria for ccHP viz. 1) clinical features of cryptogenic progressive restrictive lung disease, 2) high-resolution computed tomographic pulmonary abnormalities, and 3) bronchoalveolar lavage lymphocytosis (>30%). The regimen consisted of an initial induction phase of 3-month Solumedrol 1 g IV daily for 3 days followed by 1 month of Prednisone (P) 60 mg/day to tapered down to discontinuation by 3rd month. They also had received Mycophenolate mofetil (MMF) 1 g twice daily for 3 months. This stage was followed by a maintenance phase of yearly Rituximab infusions (1 g followed by 1 g 2 weeks later). Results: compared to their previous 6 months deterioration;all patients showed significant improvement in their forced vital volume, diffusion capacity for carbon monoxide, 6-minutes-walk after the induction phase (at 3 months) which improved further at 15 months with Rituximab therapy. Conclusion: After 3-month induction therapy with P and MMF;yearly R treatment is a safe, practical and effective long-term therapy for ccHP.

Dynamic changes in the radiologic manifestation of a recurrent checkpoint inhibitor related pneumonitis in a non-small cell lung cancer patient:A case report

BACKGROUND As immune checkpoint inhibitors(ICIs)have become widely used in lung cancer treatment,immune-related adverse events(irAEs)warrant sufficient attention.Checkpoint inhibitor-related pneumonitis(CIP)is one of the most concerning adverse events as it is uncommon but life threatening.CASE SUMMARY The patient whose case is reported here experienced three episodes of CIP in a span of 4 mon.Interestingly,the three episodes of CIP involved different regions of the lung separately.Taking these pneumonitis areas together makes nearly a whole lung area.CONCLUSION This case showed that recurrent CIPs may occur repeatedly until the whole lung is involved,suggesting that the follow-up period of CIP should be long enough,and the rechallenge of ICI should be done with due caution.

浅谈医学术语pneumonia与pneumonitis

根据国际权威工具书查证,作者认为,pneumonia主要用作肺实质病变的疾病名称,而pneumonitis是肺炎疾病潜在问题的一个征象,不特指一种疾病,只是"肺炎"的一个通俗名称,即肺组织炎症的一般性术语。

The mechanism and risk factors for immune checkpoint inhibitor pneumonitis in non-small cell lung cancer patients

Immune checkpoint inhibitors(ICIs)are new and promising therapeutic agents for non-small cell lung cancer(NSCLC).However,along with demonstrating remarkable efficacy,ICIs can also trigger immune-related adverse events.Checkpoint inhibitor pneumonitis(CIP)has been reported to have a morbidity rate of 3%to 5%and a mortality rate of 10%to 17%.Moreover,the incidence of CIP in NSCLC is higher than that in other tumor types,reaching 7%to 13%.With the increased use of ICIs in NSCLC,CIP has drawn extensive attention from oncologists and cancer researchers.Identifying high risk factors for CIP and the potential mechanism of CIP are key points in preventing and monitoring serious adverse events.In this review,the results of our analysis and summary of previous studies suggested that the risk factors for CIP may include previous lung disease,prior thoracic irradiation,and combinations with other drugs.Our review also explored potential mechanisms closely related toCIP,including increasedT cell activity against associated antigens in tumor and normal tissues,preexisting autoantibodies,and inflammatory cytokines.

Radiation pneumonitis after stereotactic radiation therapy for lung cancer

Stereotactic body radiation therapy(SBRT)has a locacontrol rate of 95%at 2 years for non-small cell lungcancer(NSCLC)and should improve the prognosis oinoperable patients,elderly patients,and patients withsignificant comorbidities who have early-stage NSCLCThe safety of SBRT is being confirmed in internationalmulti-institutional PhaseⅡtrials for peripheral lungcancer in both inoperable and operable patients,bureports so far have found that SBRT is a safe and effective treatment for early-stage NSCLC and early metastatic lung cancer.Radiation pneumonitis(RP)is oneof the most common toxicities of SBRT.Although mospost-treatment RP is Grade 1 or 2 and either asymptomatic or manageable,a few cases are severe,symptomatic,and there is a risk for mortality.The reportedrates of symptomatic RP after SBRT range from 9%to28%.Being able to predict the risk of RP after SBRT isextremely useful in treatment planning.A dose-effecrelationship has been demonstrated,but suggesteddose-volume factors like mean lung dose,lung V20and/or lung V2.5 differed among the reports.We foundthat patients who present with an interstitial pneumo-nitis shadow on computed tomography scan and high levels of serum Krebs von den Lungen-6 and surfactant protein D have a high rate of severe radiation pneumo-nitis after SBRT.At our institution,lung cancer patients with these risk factors have not received SBRT since 2006,and our rate of severe RP after SBRT has de-creased significantly since then.

Experimental treatment of radiation pneumonitis with human umbilical cord mesenchymal stem cells

Objective:To evaluate of the curative effect of human umbilical cord mesenchymal stem cells(hUC-MSCs)on rat acute radiation pneumonitis.Methods:Fourty rats were randomly divided into control group,radiation group,stem cell prevention group,stem cell treatment group and prednisone treatment group.All rats except those in the control group were radiated with X ray to establish the acute radiation pneumonitis damage model.The hUC-MSCs cultured in vitro was administrated to the rats of the prevention group via tail vein(1×10~6 cells/kg BW)24 h before the radiation,while the same administration was performed in the rats of the treatment group 24 h after the radiation.After 24 h post the radiation,the rats in tbe radiation group were given 0.4 mL physiological saline,and those in the prednisone group were given 1 mg/kg prednisone.All rats were,observed and executed 72 h after the radiation to defect lung histological changes.Results:After the administration of hUC-MSCs,the survival status of the rats in the prevention group and treatment group was obviously better than that in the control group.As shown by the histological staining,the morphology,proliferation activity aad bronchial state of lung tissues were better in the prevention group and treatment group than in the control group.Conclusion:The hUC-MSCs have definite therapeutic effects on acute radiation pneumonitis in rats.

Clinical features, outcomes and treatment-related pneumonitis in elderly patients with esophageal carcinoma

AIM: To investigate the clinical features and prognoses of elderly patients with esophageal carcinoma and to compare the effects of radiotherapy and rates of treatment-related pneumonitis (TRP) between elderly and non-elderly patients.

Hydrocarbon pneumonitis following fuel siphonage: A case report and literature review

BACKGROUND: People sometimes siphon fuel to fill their tanks. However, this is a potentially dangerous procedure and may cause hydrocarbon pneumonitis. We present the case of a patient with severe hydrocarbon pneumonitis after siphoning fuel. The patient underwent artifi cial ventilation and was admitted to hospital for 97 days. METHODS: We review the relevant literature for a better understanding of clinical features and management strategies for hydrocarbon pneumonitis following fuel siphonage.RESULTS: We reviewed 15 articles, which included 3 original articles and 12 case reports that reported the clinical features of fuel siphonage. In addition, we added our presented case for data analysis. A total of 40 cases were included in this review. The literature review found that hydrocarbon pneumonitis caused by fuel siphonage occurs worldwide and that most patients(80%) became symptomatic within 1 day of aspiration. Cough(70%), chest pain(62.5%), dyspnoea(55%), and fever(52.5%) presented in more than half of all patients. The right middle lobe(80%) was the predominantly involved lung fi eld; more than one-third of patients(36.7%) showed the involvement of two lobes.CONCLUSION: Patient history, computed tomographic scans of the chest, and bronchoalveolar lavage are the commonly used diagnostic tools. Supportive care remains the foundation of treatment, whereas antibiotics, steroids, and bronchoalveolar lavage are practical therapies. Patients' clinical improvement precedes the resolution of lesions on chest X-ray. Most complications arise from pulmonary lesions. The prognosis of patients suffering from hydrocarbon pneumonitis following fuel siphonage might be improved by accurate diagnosis and appropriate care.

Diagnosis and management of interstitial pneumonitis associated with interferon therapy for chronic hepatitis C

Interstitial pneumonitis(IP) is an uncommon pulmonary complication associated with interferon(IFN) therapy for chronic hepatitis C virus(HCV) infection.Pneumonitis can occur at any stage of HCV treatment,ranging from 2 to 48 wk,usually in the first 12 wk.Its most common symptoms are dyspnoea,dry cough,fever,fatigue,arthralgia or myalgia,and anorexia,which are reversible in most cases after cessation of IFN therapy with a mean subsequent recovery time of 7.5 wk.Bronchoalveolar lavage in combination with chest high resolution computed tomography has a high diagnostic value.Prompt discontinuation of medication is the cornerstone,and corticosteroid therapy may not be essential for patients with mild-moderate pulmonary functional impairment.The severity of pulmonary injury is associated with the rapid development of IP.We suggest that methylprednisolone pulse therapy followed by low dose prednisolone for a short term is necessary to minimize the risk of fatal pulmonary damage if signs of significant pulmonary toxicity occur in earlier stage.Clinicians should be aware of the potential pulmonary complication related to the drug,so that an early and opportune diagnosis can be made.

Study of the impact of CT/CT image fusion radiotherapy on V_(20) and radiation pneumonitis of non-small cell lung cancer

Objective:The aim of our study was to investigate the value of CT/CT image fusion radiation treatment planning in non-small cell lung cancer(NSCLC) and the impact on V20 and radiation pneumonitis(RP).Methods:Patients who were pathologically or cytologically diagnosed of stage IIIA and IIIB NSCLC were treated with three-dimensional conformal radiation therapy(4000 cGy).Forty patients got at least 25% tumor reduction were randomly divided into two groups:group A of regular shrink field radiotherapy(20 cases) and group B of CT/CT image fused shrink field radiotherapy(20 cases).Dosage reached 6600 cGy.Clinical data,V20 and RP were observed within 3 months after radiotherapy.Statistical analysis was conducted for the NSCLC patients.Results:22.5%(9/40) patients got RP during follow-up.Group A accounted for 6 cases(30%),and group B had 3 cases(15%).There was no marked difference between the two groups(P = 0.256),univariate analysis revealed that the IV20 of A and B groups,and IV20 and CV20 of all patients were statistically related to the incidence of RP(P < 0.05).With Wilcoxon method assay,the ipsilateral lung V20 and contralateral lung V20 had statistical significance between the two groups(P < 0.05).Conclusion:The CT/CT image infusion treatment planning could increase the radical dosage with better tumor control probability but won't increase adverse reaction.

Symptomatic Radiation Pneumonitis in NSCLC Patients Receiving EGFR-TKIs and Concurrent Oncedaily Thoracic Radiotherapy:Predicting the Value of Clinical and Dose-volume Histogram Parameters

Background and objectives:The incidence of symptomatic radiation pneumonitis(RP)and its relationship with dose-volume histogram(DVH)parameters in non-small cell lung cancer(NSCLC)patients receiving epidermal growth factor receptortyrosine kinase inhibitors(EGFR-TKIs)and concurrent once-daily thoracic radiotherapy(TRT)remain unclear.We aim to analyze the values of clinical factors and dose-volume histogram(DVH)parameters to predict the risk for symptomatic RP in these patients.Methods:Between 2011 and 2019,we retrospectively analyzed and identified 85 patients who had received EGFR-TKIs and oncedaily TRT simultaneously(EGFR-TKIs group)and 129 patients who had received concurrent chemoradiotherapy(CCRT group).The symptomatic RP was recorded according to the Common Terminology Criteria for Adverse Event(CTCAE)criteria(grade 2 or above).Statistical analyses were performed using SPSS 26.0.Results:In total,the incidences of symptomatic(grade≥2)and severe RP(grade≥3)were 43.5%(37/85)and 16.5%(14/85)in EGFR-TKIs group vs 27.1%(35/129)and 10.1%(13/129)in CCRT group respectively.After 1:1 ratio between EGFR-TKIs group and CCRT group was matched by propensity score matching,chi-square test suggested that the incidence of symptomatic RP in the MATCHED EGFR-TKIs group was higher than that in the matched CCRT group(χ^(2)=4.469,P=0.035).In EGFRTKIs group,univariate and multivariate analyses indicated that the percentage of ipsilateral lung volume receiving≥30 Gy(ilV_(30))[odds ratio(OR):1.163,95%CI:1.036-1.306,P=0.011]and the percentage of total lung volume receiving≥20 Gy(tlV_(20))(OR:1.171,95%CI:1.031-1.330,P=0.015),with chronic obstructive pulmonary disease(COPD)or not(OR:0.158,95%CI:0.041-0.600,P=0.007),were independent predictors of symptomatic RP.Compared to patients with lower iIV_(30)/tlV_(20)values(ilV_(30)and tlV_(20)<cut-off point values)and without COPD,patients with higher ilV_(30)/tlV_(20)values(ilV_(30)and tlV_(20)>cut-off point values)and COPD had a significantly higher risk for developing symptomatic RP,with a hazard ratio(HR)of 1.350(95%CI:1.190-1.531,P<0.001).Conclusion:Patients receiving both EGFR-TKIs and once-daily TRT were more likely to develop symptomatic RP than patients receiving concurrent chemoradiotherapy.The ilV_(30),tlV_(20),and comorbidity of COPD may predict the risk of symptomatic RP among NSCLC patients receiving EGFR-TKIs and conventionally fractionated TRT concurrently.

A case of interstitial pneumonitis in a patient with ulcerative colitis treated with azathioprine

The early hypersensitivity reaction and late bone marrow depression are well-known side-effects of azathioprine, whereas interstitial pneumonia is a rare complication. A 40-year old male patient had been treated with azathioprine in consequence of extensive ulcerative colitis for 10 years. He then complained of 7 d of fever, cough and catarrhal signs, without symptoms of active colitis. Opportunistic infections were ruled out. The chest X-ray, CT and lung biopsy demonstrated the presence of interstitial inflammation. Azathioprine therapy was discontinued as a potential source of the pulmonary infiltrate. In response to steroid therapy, and intensive care, the pulmonary infiltrate gradually decreased within 4 wk. Three months later, his ulcerative colitis relapsed, and ileo-anal pouch surgery was performed. In cases of atypical pneumonia, without a proven infection, azathioprine-associated interstitial pneumonitis may be present, which heals after withdrawal of the drug.

A missense variant of MASP2 is associated with increased risk of radiation pneumonitis in lung cancer patients treated with radiation therapy

Objective In this study,mannan-binding lectin-associated serine protease 2(MASP2)gene variant was evaluated to assess the risk of radiation pneumonitis(RP)in patients with pulmonary malignancies.Methods A total of 169 lung cancer patients with radiotherapy were included in our prospective study(NCT02490319)and genotyped using the Sanger sequencing method.Multivariate Cox hazards analysis and multiple testing were applied to estimate the hazard ratio(HR)and 95%confidence intervals(CIs)of all factors possibly associated with RP risk.Results Patients with mean lung disease≥15 Gy and V20≥24%had higher risk of RP≥grade 2 compared with their counterparts(HR=1.888,95%CI:1.186-3.004,P=0.007;HR=2.126,95%CI:1.338-3.378,P=0.001,respectively).Importantly,CC+CA genotype of MASP2:rs12711521 was strongly associated with an increased occurrence of RP≥grade 2(HR=1.949,95%CI:1.278-2.971,P=0.002).Conclusion MASP2:rs12711521 was found to be significantly associated with RP≥grade 2 in our cohort and may thus be one of the important predictors of severe RP before radiotherapy,if further validated in larger population.

CYTOMEGALOVIRUS INTERSTITIAL PNEUMONITIS FOLLOWING ALLOGENEIC PERIPHERAL BLOOD STEM CELL TRANSPLANTATION

Objective： To explore the risk factors and prophylaxis and treatment of cytomegalovirus interstitial pneumonitis （CMV-IP） after allogeneic peripheral blood stem cell transplantation （allo-PBSCT）. Methods： 43 patients who received allo-PBSCT were allocated to either a Gancyclovir（GCV）-prophylaxis group （n=19） or a non-GCV prophylaxis group （n=24）. A comparison was made of the incidence of CMV-IP in patients given or not given prophylactic gancyclovir. Results： 9 patients in non-GCV prophylaxis group developed late CMV-IP （P〈0.05）. Graft-versus-host-disease （GVHD） may be associated with a high risk of CMV-IP. 5 cases of CMV-IP were successfully treated with GCV, but 3 cases died of CMV-IP. The most common adverse event of GCV was neutropenia, but was reversible. Conclusion： CMV infection was a major cause of interstitial pneumonitis after allo-PBSCT, which correlated strongly with the severity of GVHD. Gancyclovir was shown to be effective in both prophylaxis and treatment of CMV-IP.

Bilateral diffuse grade 5 radiation pneumonitis after intensity modulated radiation therapy for localized lung cancer

We are reporting a case of fatal radiation pneumonitis that developed six months following chemoradiation for limited stage small cell lung cancer.The patient was a 67-year-old man with a past medical history of Hashimoto's thyroiditis and remote suspicion for CREST,neither of which were active in the years leading up to treatment.He received 6600 cG y delivered in 200 cG y daily fractions via intensity modulated radiation therapy with concurrent cisplatin/etoposide followed by additional chemotherapy with dosereduced cisplatin/etoposide and carboplatin/etoposide and then received prophylactic cranial irradiation.The subsequent months were notable for progressively worsening episodes of respiratory compromise despite administration of prolonged steroids and he ultimately expired.Imaging demonstrated bilateral interstitial and airspace opacities.Autopsy findings were consistent with pneumonitis secondary to chemoradiation as well as lymphangitic spread of small cell carcinoma.The process was diffuse bilaterally although his radiation was delivered focally to the right lung and mediastinum.

Rare imaging findings of hypersensitivity pneumonitis:A case report

BACKGROUND Hypersensitivity pneumonitis(HP)is an immune-mediated syndrome caused by allergen inhalation.High-resolution computed tomography(HRCT)of HP may show diffuse ground-glass opacity,centrilobular ground-glass nodules,areas of air-trapping,thin-walled cysts,or fibrotic changes.CASE SUMMARY A 47-year-old male patient went to the hospital complaining of cough and gradual aggravation of shortness of breath.HRCT of the lung showed that multiple nodules and ground-glass high-density shadows were present in both lungs.In addition,circular high-density shadows of various sizes were widely distributed in both lungs with relatively normal lung markings inside them.But other tests did not have a positive finding that can clarify the cause.Therefore,the patient underwent a lung biopsy.The pathological results showed that the lesions tended to be HP.After 4 mo of follow-up,the lesions in the patient's lungs were absorbed spontaneously,and the symptoms of cough and shortness of breath have disappeared.The review results suggested that the patient's disease was self-healing,which was consistent with the characteristics of HP.CONCLUSION For some patients with HP,abnormal HRCT findings,such as the lesions in the lungs,can be absorbed on their own,which is an important clue in the diagnosis of the disease.Early diagnosis by lung biopsy is necessary when antigen exposure is unknown.

Interaction between Primary Care Physicians and Specialists for Diagnosis and Management of Hypersensitivity Pneumonitis

Objective: Hypersensitivity pneumonitis (HP) may be a complex syndrome rather than a single, uniform disease entity. The problems associated with HP treatment include a lack of awareness of primary care procedures and scarcity of recent information regarding HP. The main objective of this study was to investigate the problems in the interaction between primary care physicians and chest specialists. Data source: All available clinical records of cases at the Fukujuji Chest Hospital, Tokyo, between 1994 and 2005, supervised by specialists of a university hospital. Study selection: All cases suspected of HP during the period. Results: Nine cases were excluded because of insufficient records or because they did not satisfy the clinical criteria. Twenty-eight enrolled patients (14 men and 14 women;mean age, 53.0 years) were initially treated for respiratory infections by primary care physicians. The final HP types were summer-type (n = 18), bird fancier’s lung (n = 2), ventilation-related (n = 3), or undetectable antigen (n = 5). On the basis of the interval between the onset of initial symptoms and the time of referral to our hospital, the cases can be categorized into 3 groups, which may represent acute, subacute, and chronic HP. Conclusion: All patients initially received treatment on the basis of a different diagnosis at primary evaluation. We concluded that interaction between primary care physicians and chest specialists is essential for solving problems associated with the early diagnosis and adequate treatment of HP.

A puzzling case of differentiation syndrome mimicking SARS-CoV2 pneumonitis: a case report

Differentiation syndrome is a complication commonly encountered in acute promyelocytic leukemia patients when treated with Al-Trans retinoic acid.This Differentiation syndrome has veryclose similarities clinically and radiologically to SARS-CoV2 pneumonitis which makes diagnosis of differentiation syndrome challenging specially during this COVID-19 pandemic.We hereby report a case of a 68-year-old male with acute promyelocytic leukemia who on initiation of Al-Trans retinoic acid developed acute respiratory distress with radiological findings of multiple ground glass opacities in bilateral lungs suggestive of SARS-CoV2 pneumonitis.Considering the radiological similarities to differentiation syndrome and on high clinical suspicion,this patient was immediately started on steroids with which he recovered rapidly.During this pandemic of SARS-CoV2,distinguishing differentiation syndrome from SARS-CoV2 pneumonitis clinically and radiologically is extremely challenging.