A 54 year old Caucasian male with a history of polysubstance abuse and stage IA squamous cell lung carcinoma resected 2 years previously, presented to clinic with a 3 month history of progressive chest pain and dyspnea on exertion. Physical examination revealed normal vital signs and no abnormalities on cardiopulmonary examination. Chest x-ray revealed a new mass in the anterior left lower mediastinum. Computerized tomography (CT) imaging of the chest showed a 7.8×3.8 cm right atrial soft tissue mass infiltrating the lateral wall of the right atrium with associated pericardial effusion, and a 5 cm pericardiophrenic mass, both new when compared to CT imaging performed 6 months previously (). Transthoracic echocardiography showed a large irregular, mural right atrial mass in the area of the tricuspid annulus with extensive infiltration of both ventricles and the posterior wall of the left atrium. In addition, he was noted to have a pericardial effusion with early tamponade physiology. A percutaneous core needle biopsy of the pericardiophrenic mass was performed (). Hematoxylin and eosin stained sections of the mediastinal mass revealed a dense infiltrate of primarily small lymphocytes with irregular nuclear contours in a background of focal fibrosis and scattered histiocytes. Immunohistochemistry and in situ hybridization demonstrated that the neoplastic cells co-expressed CD3ε, CD56, Epstein-Barr virus encoded RNA, granzyme-B, and TIA-1. Mitotic figures were easily found, but angiodestruction was not present. The final pathologic diagnosis was extranodal NK/T-cell lymphoma, nasal-type.
Computerized tomography imaging confirms a large left pericardiac mass (top right arrow) and infiltrative mass arising from the right atrium (left arrow).
Figure 2 Extranodal NK/T-cell lymphoma, nasal type. Hematoxylin and eosin stained sections of the mediastinal mass reveals a dense infiltrate of primarily small lymphocytes with irregular nuclear contours (A) and immunohistochemistry shows the neoplastic cell (more ...)
A unilateral bone marrow biopsy did not show any morphologic evidence of involvement by lymphoma. Flow cytometry on the bone marrow biopsy was negative and immunostaining for EBER was negative. Retrospective review of his non-small cell lung cancer biopsy confirmed squamous carcinoma with no atypical findings, and EBER immunostaining was negative. His blood counts at diagnosis were normal, including a normal LDH of 160 U/L. HIV testing was negative. Nasal endoscopy with biopsies and CT/PET imaging were recommended in order to complete the staging evaluation. Multiple attempts were made to schedule and perform these procedures, but the patient was unwilling and/or unable to comply due to his chaotic psychosocial circumstances and his concerns about costs due to lack of medical insurance.
Although a more dose-intensive regimen would have been preferred, CHOP chemotherapy was administered for palliative treatment in this case due to issues with poor patient compliance and continued polysubstance abuse. Two attempts had been made to administer the more dose-intensive SMILE (steroids, methotrexate, ifosfamide, L-asaparaginase, and etoposide) regimen as an inpatient, but the patient left within several hours of admission against medical advice. There were several intervening emergency department visits with tachyarrhythmias and cocaine intoxiciation. Based on these limiting factors, the patient received 2 cycles of CHOP chemotherapy as an outpatient, but demonstrated disease progression on follow up CT imaging. The patient was then referred for palliative radiotherapy which he tolerated well with improved symptoms of chest pain and dyspnea. He developed acute abdominal pain approximately 1 week after completing radiotherapy, and repeat CT imaging showing a new confluent soft tissue mass encasing the duodenum, pancreatic head, and inferior vena cava. He died from progressive lymphoma within 2 weeks of completing palliative radiotherapy.