Congenital cystic lesions of the lung are uncommon and a conjunction of two or more lesions is very rare. We report here on a case of coexisting intrapulmonary bronchogenic cyst and congenital cystic adenomatoid malformation in a 13-year-old female with a cystic mass in the right upper lobe of the lung. Computed tomography showed a cystic lesion measuring 2.5 cm with an air fluid level and surrounding multicystic lesions in the right upper lobe. On gross examination, the cut surface showed a cystic mass containing inspissated mucinous material, and the cystic mass was surrounded by multiple small cysts. Microscopically, the larger cystic cavity was lined with pseudostratified ciliated columnar epithelium. The submucosal tissue contained mucinous glands and plates of cartilage. The surrounding smaller cysts or irregular spaces were lined with bronchiolar-type respiratory epithelium. We propose that this hybrid lung lesion may represent the missing link in a common embryologic pathway determined by the timing of mesenchymal and epithelial interactions.
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Case 2: Coexisting Cystic Lesions of Lung in a Term Neonate: A Management Dilemma Bichitrananda Raut, Aakriti Soni, Susanta Kumar Badatya, Satish Saluja, Manoj Modi, Arun Soni NeoReviews.2018; 19(9): e542. CrossRef
BACKGROUND Congenital cystic adenomatoid malformation (CCAM) is a congenital abnormality of branching morphogenesis of the lung. Thyroid transcription factor-1 (TTF-1) is detected in human respiratory epithelial cells from 11 weeks of gestation, and at full term, TTF-1 expression is confined within type II epithelial cells and in some respiratory nonciliated bronchiolar epithelial cells. Immunoexpression of bcl-2 is intimately related to apoptosis during the development. METHODS To elucidate the nature of the lesion, TTF-1 expression was evaluated in twenty-four cases of CCAM (eight cases of type 1 and sixteen cases of type 2) along with immunostaining for bcl-2. For the control group, four cases of fetal lungs (19 week-, 21 week-, 27 week- and 40 week-gestational age) were also evaluated. In all cases of CCAM, TTF-1 was detected in the nuclei of epithelial cells lining the cysts. RESULTS TTF-1 was expressed in the majority of the bronchiolar-like epithelial cells of the cysts in CCAM types 1, and 2, where almost 100% of the lining cells of the cysts were TTF-1 positive with variable intensity, while negative TTF-1 expressions were found in the alveolar-like epithelium of the adjacent alveoli or distal nonciliated bronchi. For bcl-2 immunostaining, no lining epithelial cells of the cysts were stained except for the infiltrating lymphocytes.
In the control group, strong immunoreactivities found in early fetal stages were absent in the full-term aged lung (40 gestational weeks). CONCLUSION These results support the hypothesis that CCAM types 1 and 2 reflect the abnormalities in lung morphogenesis and differentiation that are distinct from those for normally developed alveolar epithelium or adjacent bronchial epithelium, thus retaining the abnormal TTF-1 immunoreactions. Though restricted to CCAM types 1 and 2 in this study, CCAM might be related to TTF-1 rather than apoptosis in the morphogenesis of the developing lung.