IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 13, Issue 9 Ver. VIII (Sep. 2014), PP 12-15 www.iosrjournals.org www.iosrjournals.org 12 | Page Fine needle aspiration cytology of giant chondroid hamartoma of lung with review of literature. 1 Dr. Manisha Mahata, 2 Dr. Sambit Dasgupta*, 3 Dr. Suman Ghosh, 4 Dr. Soumita Ghosh Sengupta, 5 Prof. Ranu Sarkar, 6 Prof. Jayati Chakrabarty 1,2 MD(Path), Demonstrator Acquisition of data, analysis and interpretation of data, drafting the article, revising it critically for important intellectual content, final approval of the version to be published 3.4.5. MD(Path), Assistant Professor Analysis and interpretation of data, revising it critically for important intellectual content final approval of the version to be published. 6 MD(Path), Professor Analysis and interpretation of data, revising it critically for important intellectual content final approval of the version to be published. Abstract: Giant pulmonary hamartoma (diameter > 9cms) is a very uncommon benign tumor with only eleven reported cases. Here we report such a rare case of giant pulmonary hamartoma measuring 12cms in diameter occupying almost whole of the left hemithorax. CT guided FNAC was done in suspicion of a malignant tumor but the cytomorphological features were of a benign cartilaginous neoplasm. The cytological findings were correlated with the radiological features and a diagnosis of chondroid hamartoma was suggested on FNAC. The diagnosis was later confirmed by histopathological examination. Key Words: lung, giant chondroid hamartoma, fine needle aspiration cytology I. Introduction Pulmonary hamartoma, also known as chondroma, chondroid hamartoma, chondroid adenoma, mesenchymoma, is the most common type of benign lung tumours, composed of varying proportions of mesenchymal tissues with entrapped respiratory epithelium. They were considered as developmental abnormalities in the past but now considered as benign mesenchymal neoplasms. [1-5] Incidence of pulmonary hamartoma is 0.25% with a two to four fold male preponderance, most occurring in 6 th decade of life. Most often it is incidentally discovered as solitary nodule on chest x-ray. [1,2,3] They are usually peripheral and less than 5cm in diameter. Giant pulmonary hamartoma ( measuring >9cm in diametre ) is very rare and only 11 cases have been published till date [6-13] . Here we present a 27 years old female with a giant chondroid hamartoma, measuring 12 cms in diametre extending from periphery to bronchus, in the left lung. II. Case Report A 27 year old female was admitted to our hospital with cough, fever, and left-sided chest pain of 8 months duration. She had an episode of haemoptysis. Physical examination revealed decreased breath sounds in the left side. Routine blood and biochemical parameters were within normal limits. Sputum was negative for acid-fast bacilli. X-ray revealed a large homogeneous opacity occupying almost whole of the left hemithorax blurring the left C-P angle. CT-scan (Figure 1) confirmed a large, heterogeneous mass measuring 12 cms in diameter occupying almost entire left hemithorax with extensive nodular (popcorn) calcification. Mediastinum was displaced to right. Left bronchus was compressed. No mediastinal lymphadenopathy or pleural effusion was documented. Radiological impression suggested a malignant neoplasm. CT-guided FNAC of the lesion was done. Smears were stained by May-Grünwald-Giemsa and Papanicolaou (Pap) stains. Smears were moderately cellular comprising of round to ovoid cells with nucleomegaly and anisonucleosis, moderate amount of pale cytoplasm in a fibromyxoid background. There were also sheets of broncholiolar epithelium interspersed with fat cells and with foci of calcified spherules (Figure 2). Based on cytology a strong suspicion of chondroid hamartoma was made. Percutaneous transthoracic needle biopsy, the main diagnostic approach, showed predominantly cartilaginous tissue & confirmed the diagnosis (Figure 3A, 3B, 3C ). Endobronchial biopsy showed immature cartilaginous cells having acidophilic cytoplasm that resemble histiocytes along with plump fibroblast & smooth muscle fibres (Figure 3D, 3E). The patient is on follow-up and awaiting surgery.