Ans. (d) Small round cells and hyperchromatic nuclei with nuclear moulding(Ref: Robbins 9th/pg 715-717)This typical presentation of 60 yr/M presenting with a mass located at central bronchus causing distal bronchiectasis and recurrent pneumonia is suggestive of small cell Carcinoma.In Small cell Ca lung, location in lungs are most commonly central and usually presents with mass within the bronchus.Light Microscopy feature of Small cell Ca is:Small cells with salt and pepper pattern, hyperchromatic nuclei, Q, nuclear molding Q is prominentBasophilic staining of vascular walls due to encrustation by DNA from necrotic tumor cells (Azzopardi effect) QAbout other options:A. Abundant osteoid matrix formation points towards metastatic Osteosarcoma;B. Contains all three germ layers: is consistent with a Teratoma;C. Spindle cells with abundant stromal matrix is suggestive of Sarcoma;