SESSION TITLE: Lung Cancer Imaging Case Report Posters 2SESSION TYPE: Case Report PostersPRESENTED ON: 10/19/2022 12:45 pm - 01:45 pmINTRODUCTION: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma (NHL), often presenting as a rapidly enlarging, symptomatic mass in nodal sites. In 40% of cases, DLBCL begins in an extra-nodal site, most commonly within the GI tract, although the disease can arise in any organ. Systemic "B” symptoms are observed in 30% of patients. Asymptomatic, incidentally discovered DLBCL has rarely been described in the literature. We present a case of primary pulmonary DLBCL discovered incidentally on chest imaging.CASE PRESENTATION: A 62-year-old male with a past medical history of venous thromboembolic disease presented for evaluation of a concerning skin lesion & was diagnosed with nodular melanoma. The patient was otherwise asymptomatic. A pre-operative chest X-ray showed a left lower lobe opacity. Computed tomography of the chest revealed an 8 cm mass encasing and occluding the left lower lobe bronchus with associated post-obstructive consolidation. [FIGURE 1] PET scan showed FDG-avidity of the lung mass and right axillary, mediastinal, and hilar lymph nodes. [FIGURE 2] EBUS-FNA of lymph nodes was negative for malignancy. Findings were confirmed on repeat bronchoscopy in one week. Following a 6-week course of antibiotics, a repeat CT scan showed enlargement of the mass. CT-guided biopsy revealed DLBCL, germinal center B-cell subtype. Immunohistochemistry was positive for BCL6 and c-Myc and a Ki67 index of 80%. The patient is currently undergoing R-CHOP chemotherapy.DISCUSSION: DLBCL is the most common lymphoma and comprises 25% of all NHLs. Patients typically present with a rapidly enlarging mass and systemic "B” symptoms. DLBCL can be locally invasive, causing compression of vessels, airways, peripheral nerves, and bony destruction with presenting symptoms of such invasion.Asymptomatic cases of DLBCL have rarely been described. Furthermore, primary pulmonary DLBCL is rare, comprising only 10% of primary pulmonary lymphomas. This case is an unusual presentation of primary pulmonary DLBCL as it was discovered incidentally in an asymptomatic patient. The rapidly enlarging lung tumor was encasing the left lower lobe bronchus with associated post-obstructive consolidation. Throughout the diagnostic process, however, the patient continually denied symptoms such as shortness of breath, fever, or night sweats. Interestingly, the patient reported an intentional 40-45-lb weight loss during the 9 months leading to DLBCL discovery. The patient's weight loss efforts may have masked cancer-related weight loss.CONCLUSIONS: This case highlights the importance of pre-operative evaluation and thorough history and physical examination of every patient, regardless of presenting symptoms. Determined investigation should continue if any clinical suspicion remains following negative test results. DLBCL may progress asymptomatically, and rapid initiation of treatment is key.Reference #1: Li, Shaoying et al. "Diffuse large B-cell lymphoma.” Pathology vol. 50,1 (2018): 74-87. doi:10.1016/j.pathol.2017.09.006.Reference #2: Garzon, Jr Garcia et al. "Incidental diagnosis of diffuse large B-cell lymphoma by 11C-choline PET/CT in a patient with biochemical recurrence of prostate cancer.” Clinical nuclear medicine vol. 39,8 (2014): 742-3. doi:10.1097/RLU.0000000000000495.Reference #3: Xu, Huiting et al. "Primary Pulmonary Diffuse Large B-Cell Lymphoma on FDG PET/CT-MRI and DWI.” Medicine vol. 94,29 (2015): e1210. doi:10.1097/MD.0000000000001210.DISCLOSURES: No relevant relationships by Mohammed AlnijoumiNo relevant relationships by Madeline Simon SESSION TITLE: Lung Cancer Imaging Case Report Posters 2 SESSION TYPE: Case Report Posters PRESENTED ON: 10/19/2022 12:45 pm - 01:45 pm INTRODUCTION: Diffuse large B-cell lymphoma (DLBCL) is the most common form of non-Hodgkin lymphoma (NHL), often presenting as a rapidly enlarging, symptomatic mass in nodal sites. In 40% of cases, DLBCL begins in an extra-nodal site, most commonly within the GI tract, although the disease can arise in any organ. Systemic "B” symptoms are observed in 30% of patients. Asymptomatic, incidentally discovered DLBCL has rarely been described in the literature. We present a case of primary pulmonary DLBCL discovered incidentally on chest imaging. CASE PRESENTATION: A 62-year-old male with a past medical history of venous thromboembolic disease presented for evaluation of a concerning skin lesion & was diagnosed with nodular melanoma. The patient was otherwise asymptomatic. A pre-operative chest X-ray showed a left lower lobe opacity. Computed tomography of the chest revealed an 8 cm mass encasing and occluding the left lower lobe bronchus with associated post-obstructive consolidation. [FIGURE 1] PET scan showed FDG-avidity of the lung mass and right axillary, mediastinal, and hilar lymph nodes. [FIGURE 2] EBUS-FNA of lymph nodes was negative for malignancy. Findings were confirmed on repeat bronchoscopy in one week. Following a 6-week course of antibiotics, a repeat CT scan showed enlargement of the mass. CT-guided biopsy revealed DLBCL, germinal center B-cell subtype. Immunohistochemistry was positive for BCL6 and c-Myc and a Ki67 index of 80%. The patient is currently undergoing R-CHOP chemotherapy. DISCUSSION: DLBCL is the most common lymphoma and comprises 25% of all NHLs. Patients typically present with a rapidly enlarging mass and systemic "B” symptoms. DLBCL can be locally invasive, causing compression of vessels, airways, peripheral nerves, and bony destruction with presenting symptoms of such invasion. Asymptomatic cases of DLBCL have rarely been described. Furthermore, primary pulmonary DLBCL is rare, comprising only 10% of primary pulmonary lymphomas. This case is an unusual presentation of primary pulmonary DLBCL as it was discovered incidentally in an asymptomatic patient. The rapidly enlarging lung tumor was encasing the left lower lobe bronchus with associated post-obstructive consolidation. Throughout the diagnostic process, however, the patient continually denied symptoms such as shortness of breath, fever, or night sweats. Interestingly, the patient reported an intentional 40-45-lb weight loss during the 9 months leading to DLBCL discovery. The patient's weight loss efforts may have masked cancer-related weight loss. CONCLUSIONS: This case highlights the importance of pre-operative evaluation and thorough history and physical examination of every patient, regardless of presenting symptoms. Determined investigation should continue if any clinical suspicion remains following negative test results. DLBCL may progress asymptomatically, and rapid initiation of treatment is key. Reference #1: Li, Shaoying et al. "Diffuse large B-cell lymphoma.” Pathology vol. 50,1 (2018): 74-87. doi:10.1016/j.pathol.2017.09.006. Reference #2: Garzon, Jr Garcia et al. "Incidental diagnosis of diffuse large B-cell lymphoma by 11C-choline PET/CT in a patient with biochemical recurrence of prostate cancer.” Clinical nuclear medicine vol. 39,8 (2014): 742-3. doi:10.1097/RLU.0000000000000495. Reference #3: Xu, Huiting et al. "Primary Pulmonary Diffuse Large B-Cell Lymphoma on FDG PET/CT-MRI and DWI.” Medicine vol. 94,29 (2015): e1210. doi:10.1097/MD.0000000000001210. DISCLOSURES: No relevant relationships by Mohammed Alnijoumi No relevant relationships by Madeline Simon