extranodal involvement in the cases of nonhodgkin 's lymphoma ( nhl ) is a known entity with gastrointestinal tract leading the list , followed by skeletal system , skin , kidneys and other rare organs . however , pure extranodal forms ( often referred to as primary ) are rare events , and the definition often requires either absence of nodes or the primary site should be the largest one . primary involvement of lung was observed in around 0.4% of all extranodal lymphomas . wherever reported , malt - type lymphomas are more common , followed by diffuse large cell variants . anaplastic variants are the rarest forms and we report here one such rare case and review the literature . a 46-year - old male smoker presented with a history of dry cough and moderate - grade pyrexia , responding to antipyretic since 3 months the patient was provisionally diagnosed as a case of tuberculosis and started on the anti - tubercular therapy . the blood investigations were within normal range and imaging [ figure 1 ] of the thorax showed a mass lesion in the upper lobe of the right lung and abdominal scans were within normal range . fine needle aspiration biopsy from the lesion showed atypical cells suggestive of malignancy . for further confirmation , immunohistochemical ( ihc ) markers were performed on cell block , which suggested lca positive , ck ( cytokeratin ) negative , other markers were inconclusive . the cytogenetics from the lesion suggested t ( 2 : 5 ) though anaplastic lymphoma kinase ( alk ) was negative . staging evaluation suggested that it was extranodal lymphoma stage i b e ( bone marrow examination showed no involvement ) . the primary anaplastic large cell lymphoma of lung was the final diagnosis made and patient was started on combinational chemotherapy consisting of cyclophosphamide , adriamycin , vincristine and prednisolone . though lung involvement in cases of lymphoma is observed in as high as 40% of cases , in autopsy series , the exact clinical incidence is not known . however , primary pulmonary lymphomas ( ppls ) are extremely rare 0 ( 0.4% ) , and whenever present they are of malt type , with occasional diffuse large cell lymphomas . it was hypothesized that the high incidence of malt type of lymphomas in lung are mainly due to the chronic antigenic stimulation ( with etiological agents ranging from smoking , autoimmune disorders , infections and occupational exposure to irritants ) . clinically they often present with incidental diagnosis ( asymptomatic ) in around 50% of cases , followed by occasional cough and hemoptysis with b symptoms being extremely uncommon . the diagnosis is often delayed and sometimes missed owing to its resemblance with other similar entities like pseudo - lymphoma , lymphoid interstitial pneumonitis and lymphomatoid granulomatosis.[48 ] in such circumstances , ihc features help to differentiate ppl from the above . one of the largest reported series showed that most of them ( 54% ) are malt type , followed by diffuse large cell variants ( 28% ) and other rare forms ( 18% ) . primary anaplastic large cell lymphoma is a rare entity among these and to the best of our search ; the largest reported series had five cases . though diagnostic criteria does not exist for this entity , presence of the characters mentioned below are widely accepted . presence of unilateral or bilateral pulmonary involvement by nhlno evidence of mediastinal adenopathy or extrathoracic diseaseno past history of lymphoma . presence of unilateral or bilateral pulmonary involvement by nhl no evidence of mediastinal adenopathy or extrathoracic disease no past history of lymphoma . the natural course of this rare disease is usually indolent and responds favorably to treatment , with only few exceptions where the disease is aggressive . wherever the disease is having an indolent course , usually local modalities like surgery with or without radiation is adequate . pathological type and aggressiveness of the disease at presentation ( including duration of symptoms ) are usually important prognostic factors and role of internatinal prognostic index [ ipi ] score in these cases is not studied yet .
a 46-year - male smoker presented with cough and fever to a chest physician , who on the basis of chest x - ray started him on antitubercular treatment . however , further evaluation suggested that the patient was suffering from a rare disease , i.e. anaplastic large cell lymphoma of lung . 
 although lung involvement in cases of lymphoma is observed in as high as 40% of cases , in autopsy series , the exact clinical incidence is not known . 
 one of the largest lymphoma groups reported it to be around 25% . 
 however , primary pulmonary lymphomas have been extremely rare ( 0.4% ) , and whenever present they are of ( mucosa associate lymphoid tissue ) malt type , with occasional diffuse large cell lymphomas . 
 the anaplastic variant is extremely uncommon . 
 usually the treatment results are satisfactory with more than 80% of the cases surviving even after 3 years . here 
 we report the case of anaplastic primary nonhodgkin 's lymphoma of lung and review the literature .