Image Diagnosis: Bronchioloalveolar Carcinoma Presenting as Unilateral “Crazy-Paving” Pattern on High-Resolution Computed Tomography

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Vikas Pilaniya, MD; Shekhar Kunal, MBBS; Sudhir Jain, MD; Ashok Shah, MD

Perm J 2016 Spring;20(2):e111-e112

https://doi.org/10.7812/TPP/15-102

Case Report

A 70-year-old man presented to our hospital with 18 months of cough and breathlessness. He was tachypneic and had decreased breath sounds and coarse crackles over his left chest. He was human immunodeficiency virus-negative and had never smoked. The 6-minute walk test revealed blood oxygen desaturation from 94% to 86%. The patient was admitted to the hospital for further tests and monitoring to establish a diagnosis.

A radiograph of the patient’s chest showed inhomogeneous opacity in left mid and left lower zones (Figure 1). A high-resolution computed tomography (HRCT) scan done one year before presentation highlighted a classic “crazy-paving” pattern, where thickened interlobular septa and intralobular lines, with distinct geographic margins on a background of ground-glass opacification, could be seen in the left upper lobe (Figure 2A). HRCT performed on presentation showed that in the intervening year the lesion had increased dramatically along with minimal left-side pleural effusion (Figure 2B). Sputum stains and cultures for Mycobacterium tuberculosis, fungi, and other aerobic organisms were negative. Fiberoptic bronchoscopy showed no gross abnormality. Bronchial aspirate was negative for all organisms, as was the GeneXpert test for M tuberculosis. Transbronchial biopsy confirmed bronchioloalveolar carcinoma (BAC) (Figures 3A and 3B).

These investigations were carried out during the patient’s five-day stay in our institution. After confirmation of the diagnosis, he was referred to a tertiary oncology center for further management and was lost to follow-up.

Discussion

The first-ever portrayal of crazy-paving on HRCT was recorded in a patient with pulmonary alveolar proteinosis and is still considered a hallmark of the disease.¹ Since then, a number of clinical conditions have been associated with this radiologic pattern visible on HRCT.² This pattern has also been reported in viral/opportunistic infections, Pneumocystis carinii pneumonia, exogenous lipoid pneumonia, diffuse alveolar haemorrhage, and sarcoidosis.³ The crazy-paving pattern appears on HRCT as diffuse ground-glass opacification superimposed with interlobular septal thickening and intralobular lines in a geographic distribution resembling irregularly laid cobblestones. These areas are usually bilateral and feature distinct margins, which sharply demarcate these areas from the normal lung parenchyma.^3,4 It has been postulated that the crazy-paving pattern occurs because of processes that cause alveolar filling, because of interstitial fibrosis, or because of a combination of both of these elements.²

BAC, a term coined by Liebow in 1960,⁵ accounts for approximately 4% of all primary lung malignancies. It is more common in females and never-smokers.⁶ The radiologic presentations of BAC are diverse and range from solitary or multiple pulmonary nodules to cystic disease, cavitation, and consolidation. Most consolidations in BAC are peripheral in location, can persist for a long duration, and can be difficult to differentiate from consolidation of an infective origin.⁷

The revised World Health Organization lung tumor classification⁸ recognized this infrequently seen clinical entity as a subtype of adenocarcinoma with three distinct histologic forms: mucinous, nonmucinous, and mixed or indeterminate.⁸ In 2011, the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society⁹ proposed that BAC be categorized under four new subtypes: adenocarcinoma in situ; minimally invasive adenocarcinoma; lepidic predominant nonmucinous adenocarcinoma; and invasive mucinous adenocarcinoma. The preinvasive lesion subtypes included adenocarcinoma in situ and minimally invasive adenocarcinoma. The invasive subtypes were lepidic predominant nonmucinous adenocarcinoma and invasive mucinous adenocarcinoma. The main purpose of this newer classification was to delineate categories having distinct clinical, radiologic, and histologic characteristics.⁹ However, the term BAC is still widely used.

BAC presenting radiologically as a crazy-paving pattern is a distinct rarity.¹⁰ BAC should always be considered in the differential diagnosis of this singularly unusual HRCT imaging pattern.

Disclosure Statement

The author(s) have no conflicts of interest to disclose.

References

1.    Murch CR, Carr DH. Computed tomography appearances of pulmonary alveolar proteinosis. Clin Radiol 1989 May;40(3):240-3. DOI: https://doi.org/10.1016/S0009-9260(89)80180-1.
    2.    Johkoh T, Itoh H, Müller NL, et al. Crazy-paving appearance at thin-section CT: spectrum of disease and pathologic findings. Radiology 1999 Apr;211(1):155-60. DOI: https://doi.org/10.1148/radiology.211.1.r99ap10155.
    3.    Rossi SE, Erasmus JJ, Volpacchio M, Franquet T, Castiglioni T, McAdams HP. “Crazy-paving” pattern at thin-section CT of the lungs: radiologic-pathologic overview. Radiographics 2003 Nov-Dec;23(6):1509-19. DOI: https://doi.org/10.1148/rg.236035101.
    4.    Hansell DM, Bankier AA, MacMahon H, McLoud TC, Müller NL, Remy J. Fleischner Society: glossary of terms for thoracic imaging. Radiology 2008 Mar;246(3):697-722. DOI:
https://doi.org/10.1148/radiol.2462070712.
    5.    Liebow AA. Bronchiolo-alveolar carcinoma. Adv Intern Med 1960;10:329-58.
    6.    Read WL, Page NC, Tierney RM, Piccirillo JF, Govindan R. The epidemiology of bronchioloalveolar carcinoma over the past two decades: analysis of the SEER database. Lung Cancer 2004 Aug;45(2):137-42.  DOI: https://doi.org/10.1016/j.lungcan.2004.01.019.
    7.    Mir E, Sareen R, Kulshreshtha R, Shah A. Bronchioloalveolar cell carcinoma presenting as a “non-resolving consolidation” for two years. Pneumonol Alergol Pol 2015;83(3):208-11. DOI: https://doi.org/10.5603/PiAP.2015.0033.
    8.    Travis WD, Brambilla E, Müller-Hermelink HK, Harris CC. Tumours of the lung. In: Travis WD, Brambilla E, Müller-Hermelink HK, Harris CC, editors. Pathology and genetics of tumours of the lung, pleura, thymus and heart. 3rd ed. WHO classification of tumours, volume 10. Lyon, France: IARC Press; 2004. p 10.
    9.    Travis WD, Brambilla E, Noguchi M, et al. International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society international multidisciplinary classification of lung adenocarcinoma. J Thorac Oncol 2011 Feb;6(2):244-85. DOI: https://doi.org/10.1097/JTO.0b013e318206a221.
    10.    Tan RT, Kuzo RS. High-resolution CT findings of mucinous bronchioloalveolar carcinoma: a case of pseudopulmonary alveolar proteinosis. AJR Am J Roentgenol 1997 Jan;168(1):99-100. DOI: https://doi.org/10.2214/ajr.168.1.8976928.