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Year : 2021  |  Volume : 10  |  Issue : 3  |  Page : 358-360

Adenocarcinoma masquerading as cryptogenic organizing pneumonia: An unusual presentation

1 Department of Pulmonary Medicine, Sher-I-Kashmir Institute of Medical Sciences, Soura, Srinagar, Jammu and Kashmir, India
2 Department of Pathology, Sher-I-Kashmir Institute of Medical Sciences, Soura, Srinagar, Jammu and Kashmir, India

Date of Submission11-Feb-2021
Date of Decision29-Jun-2021
Date of Acceptance28-Jul-2021
Date of Web Publication13-Sep-2021

Correspondence Address:
Dr. Nazia Mehfooz
Department of Pulmonary Medicine, Sher-I-Kashmir Institute of Medical Sciences, Soura, Srinagar-190011, Jammu and Kashmir
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijrc.ijrc_25_21

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A case of elderly female is presented who had both clinical and radiological features of Cryptogenic organizing pneumonia. The patient did not respond to medical treatment. Bronchoscopy and transbronchial lung biopsy were done . The case finally proved to be adenocarcinoma lung.

Keywords: Adenocarcinoma, cryptogenic organizing pneumonia, multifocal, unusual

How to cite this article:
Mehfooz N, Koul P, Shah T, Khursheed S, Jan R, Shah S, Hamid R. Adenocarcinoma masquerading as cryptogenic organizing pneumonia: An unusual presentation. Indian J Respir Care 2021;10:358-60

How to cite this URL:
Mehfooz N, Koul P, Shah T, Khursheed S, Jan R, Shah S, Hamid R. Adenocarcinoma masquerading as cryptogenic organizing pneumonia: An unusual presentation. Indian J Respir Care [serial online] 2021 [cited 2021 Dec 2];10:358-60. Available from: http://www.ijrc.in/text.asp?2021/10/3/358/325877

  Introduction Top

Multifocal bilateral consolidation on chest imaging is a common finding seen in many respiratory and nonrespiratory diseases. The usual causes are either infectious or inflammatory.[1] The common differentials for bilateral multifocal consolidations are cryptogenic organizing pneumonias, atypical viral pneumonias, fungal infections, hypersensitivity pneumonias, and eosinophilic pneumonias.[1] Cryptogenic organizing pneumonia (COP) is a primary organizing pneumonia with no known cause and is classified as an idiopathic interstitial pneumonia.[2] Lung malignancy should be considered as one of the causes, especially when patient is nonresponsive to systemic corticosteroids and antibiotics.

We report a case of multifocal well-differentiated adenocarcinoma that was initially believed to be as COP due to similar clinical manifestation and radiological features leading to delay in the diagnosis.

  Case Report Top

Sixty-seven-year-old nonsmoker female with no past medical history presented with persistent cough and dyspnea at rest from the past 1 year. The symptoms were gradual in onset and progressively worsening from the past 6 months with sputum became copious and watery (bronchorrhea).

There is no history of chest pain, night sweats, hemoptysis, and significant weight loss. The patient was treated by many general practitioners with multiple courses of cough suppressant's, antihistaminic, and systemic steroids.

The patient reported to our institute as she had no relief in symptoms. The patient had hypoxemia on admission (spo2 – 85%). She was treated by antibiotics, systemic steroids, and oxygen inhalation. There was no improvement observed in the patient's condition.

Malignant process was suspected at this stage in view of failure to response to treatments and nonresolving pneumonia.

Routine hematological laboratory tests detected were unremarkable except mild anemia. Liver, kidney functions, and glucose levels in blood circulation were within normal ranges. There were no hematuria and no albuminuria. Serum C-reactive protein and autoimmune panel were negative. Blood culture and sputum Ziehl–Neelsen stain were negative.

Chest X-ray showed extensive bilateral air space opacities concerning for multifocal pneumonia.

Contrast-enhanced computed tomography (CECT) [Figure 1]a and [Figure 1]b showed multifocal coalescing or conglomerate consolidations with air bronchogram sign in bilateral lung fields. Ground-glass (GG) opacities and multiple nodules were seen in random distribution with cavitary nodule in posterobasal segments of the left lower lobe and few subcentimetric lymph nodes.
Figure 1: (a) Shows bilateral multifocal patchy consolidation with air bronchogram sign (red arrows). Also seen ground-glass opacities (b) Shows bilateral multiple lung nodules (red arrows)

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Initially, we entertained a differential diagnosis of COP, chronic eosinophilic pneumonia, tuberculosis, and bronchoalveolar neoplasms based on clinic-radiological picture.

Bronchoscopy revealed a normal tracheal mucosa and lumen except copious mucoid secretions present in the tracheobronchial tree. No endobronchial lesion was observed. Bronchoalveolar lavage (BAL) and transbronchial biopsy were performed.

BAL specimen showed no evidence of eosinophilia and was negative for bacteria, Mycobacterium tuberculosis, and atypical cells. Transbronchial lung biopsy (TBLB) on histopathological examination (HPE) showed well-differentiated adenocarcinoma immunoreactive for thyroid transcription factor-1 (TTF-1) [Figure 2]a and [Figure 2]b. Molecular analysis revealed an epidermal growth factor receptor (EGFR) exon-20 (insertion) mutation within the tumor specimen. The tumor was negative for ROS and ALK mutation. The plan was to start the patient on osimertinib, in light of positive EGFR mutation.
Figure 2: (a) H and E ×20 section reveals adenocarcinoma moderately differentiated. (b) ×20 thyroid transcription factor positive adenocarcinoma

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  Discussion Top

Our patient elderly female nonsmoker presented with cough and progressive dyspnea. CECT of the chest showed multifocal bilateral consolidation with air bronchograms and GG opacities. Presentation of our case may be confused with pneumonia or other inflammatory conditions in the lung. Initially, COP was thought to be the diagnosis in view of similar clinical picture and radiological features including asymmetric bilateral, patchy consolidation, diffuse reticular or reticulonodular infiltration, solitary focal lesion that often mimics lung cancer and air bronchogram sign.[3]

The patient did not respond to the course of antibiotics or corticosteroids due to which a possibility of lung malignancy was made. Fiberoptic bronchoscopic-guided TBLB settled the diagnosis to well-differentiated adenocarcinoma, immunohistochemistry staining being positive for TTF-1. As seen in our case, adenocarcinoma has been described previously with nonresolving pneumonia.[4]

It can rarely present with interstitial involvement and such reports are very few in literature.[5],[6]

The exact pathogenesis of interstitial component is not clear and likely because intense inflammation and fibrosis may obscure the malignant pathology and masquerade as interstitial lung disease.[5]

Bilateral infiltrates with multifocal GG opacities as seen in our case are unusual with well-differentiated adenocarcinoma and at present, there appears to be no consensus on the percentage of adenocarcinoma presenting as bilateral diffuse infiltrates.[1]

The American Joint Committee on Cancer/Union for International Cancer Control staging introduced four disease patterns for staging multiple simultaneous lung nodules.[7]

(1) Synchronous and metachronous primary lung cancers; (2) Separate tumor nodules with similar histopathologic features, which are staged as intrapulmonary metastases; (3) multifocal pulmonary adenocarcinoma with GG/lepidic (GG/L) features; (4) diffuse pneumonic-type lung adenocarcinoma, which usually presents as patchy areas of GG opacities and consolidations.

The eight edition of American Joint Commission on Cancer staging for lung cancer recognizes multifocal adenocarcinoma as a unique disease entity and adopts the size of the largest nodule for staging.[8]

The case described has the EGFR exon-20 (insertion) mutation in EGFR gene. Adenocarcinoma with EGFR mutations is more common in women[1] as seen in our case. The common reasons for such gender distribution are estrogen status, exposure to domestic work with burning coal, or other forms of smoke-producing fuel.[9] Many authors over the past few years have observed several unique characteristics of multifocal adenocarcinomas such as they tend to occur among female nonsmokers and may exhibit a lower tendency for nodal or extrathoracic metastasis than other types of lung cancer as seen in our case.[8]

  Conclusion Top

Multifocal adenocarcinoma presenting as bilateral diffuse pulmonary consolidation may be mistaken for COP leading to the delay in the diagnosis. Adenocarcinoma should be considered as one of the differential diagnosis of diffuse parenchymal lung disease as it can mimic infectious or inflammatory pathology particularly if it is not responding to antibiotics and corticosteroid therapy. TBLB is a useful tool for diagnosis.

To sum up, a case of well-differentiated EGFR-positive multifocal adenocarcinoma with predominant clinical and radiological signs of cryptogenic organizing pneumonia is presented.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Thimmareddygari D, Ramahi A, Chan KH, Patel R, Bellary S, Sharma H, et al. An unusual presentation of aggressive primary invasive adenocarcinoma of lung. Am J Med Sci 2021;361:118-25.  Back to cited text no. 1
Huo JP, Liu C, Jin BB, Duan FX, Me SH, LI XC, et al. Cryptogenic organizing pneumonia masquerading as lung carcinoma: A case report and review of the literature. Exp Ther Med 2018;15:39-46.  Back to cited text no. 2
Jain S, Rathore YS, Jindal A, Josh V. Cryptogenic organizing pneumonia mimicking a mass lesion: An unusual case. Indian J Respir Care 2019;8:124-6.  Back to cited text no. 3
  [Full text]  
Thompson WH. Bronchioloalveolar carcinoma masquerading as pneumonia. Respir Care 2004;49:1349-53.  Back to cited text no. 4
Lantuejoul S, Colby TV, Ferretti GR, Brichon PY, Brambillaz C, Brambilla E. Adenocarcinoma of the lung mimicking inflammatory lung disease with honeycombing. Eur Respir J 2004;24:502-5.  Back to cited text no. 5
Raparia K, Ketterer J, Dalurzo ML, Chang YH, Colby TV, Leslie KO. Lung tumors masquerading as desquamative interstitial pneumonia (DIP): Report of 7 cases and review of the literature. Am J Surg Pathol 2014;38:921-4.  Back to cited text no. 6
Detterbeck FC, Nicholson AG, Franklin WA, Marom EM, Travis WD, Girard N, et al. The IASLC lung cancer staging project: Summary of proposals for revisions of the classification of lung cancers with multiple pulmonary sites of involvement in the forthcoming eighth edition of the TNM classification. J Thorac Oncol 2016;11:639-50.  Back to cited text no. 7
Tanvetyanon T, Boyle TA. Clinical implications of genetic heterogeneity in multifocal pulmonary adenocarcinomas. J Thorac Dis 2016;8:E1734-8.  Back to cited text no. 8
Siegfried JM. Women and lung cancer: Does estrogen play a role? Lancet Oncol 2001;2:506-13.  Back to cited text no. 9


  [Figure 1], [Figure 2]


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