Our patient is a 57-year-old male with a past medical history significant for rheumatoid arthritis who was previously on methotrexate for approximately 10 years, from October of 2012 to June of 2022. He was taken off methotrexate due to worsening leukopenia.

He was seen in the pulmonary clinic in September 2021 with complaints of 8–10 years of cough from February to May annually.

Prior to pulmonary evaluation he was being treated for asthma by his primary care provider. After the initial evaluation by his primary care provider, he was treated for the common causes of chronic cough including gastroesophageal reflux and postnasal drip.

Due to his history of long-term immunosuppression therapy that was stopped due to leukopenia, a CT scan of the thorax was performed which showed mediastinal, abdominal, and axillary lymphadenopathy and splenomegaly.

Our patient underwent bronchoscopy with endobronchial ultrasound and transbronchial needle aspiration due to concern for malignancy given the CT findings of adenopathy. The patient underwent flexible bronchoscopy with evaluation to the subsegmental level without evidence of endobronchial disease. Given his lymphadenopathy he also underwent endobronchial ultrasound and was found to have three enlarged lymph nodes. Lymph node station 2R measured 6.0mm, station 4R measured 5.5 mm and station 7 measured 8.0 mm. All three lymph node stations were sampled and station 7 was sent for flow cytometry in addition to cytopathology given the high suspicion for lymphoproliferative disorder in the setting of prior immunosuppression and organomegaly. The other lymph node stations sampled had no target tissue for pathologic review. The cytology and flow cytometry of station 7 were both negative for malignant cells. Flow cytometry showed 46% of the total cells analyzed were lymphoid cells with the predominance being 78% of the lymphoid cells were T lymphocytes and 10% were B lymphocytes. The patient was instructed to follow up in clinic with a repeat CT scan in 1 year, or sooner if there are any changes in symptoms. In September of 2022, he started to have progressively worsening shortness of breath on minimal exertion. Repeat CT scan showed a large left sided pleural effusion with left lower lobe and lingular compressive atelectasis, enlarging lymphadenopathy in the retroperitoneum and right paratracheal region, the pleural appeared to be thick and nodular with the thickest portion in the medial costophernic sulcus that measured approximately 4 cm. Given these findings malignancy, particularly lymphoma was still our main concern. Due to his symptoms a thoracentesis was performed with removal of 2.6 L of pleural fluid. The fluid was exudative by Light's criteria with lymphocytic predominance, cytology was negative and flow cytometry showed a mix of mature and T- and B- lymphocytes with 76% comprised of T cells. He underwent another thoracentesis with similar findings. After discussion with the patient about the risk and benefit of pleuroscopy and pleural biopsies, the patient agreed to undergo the procedure. The pleuroscopy showed an abnormal appearing pleura with patchy white pleural thickening, small and large adherent thick pleural nodules, erythema and hypervascularity, there was no conspicuous disease seen in the mediastinum or pericardium. WHAT IS YOUR DIAGNOSIS?