A 56-year-old man with AIDS for four years, non-compliant with his antiretroviral therapy (ART) presented with altered mental status and somnolence for four days. His family reported progressive weakness affecting his ambulation over a period of three weeks. There was no history of sick contacts, recent travel, animal exposure, or illicit drug use. An unintentional weight loss of about twenty pounds over the past four months was also reported. Patient had been started on ART four weeks prior to his hospital admission. Patient's home medications were elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (fixed dose combination), azithromycin and dapsone.
On physical examination, he was cachectic and somnolent, temperature was 97.5 F, blood pressure 112/74 mm Hg, heart rate 95 bpm, respiratory rate 16 with oxygen saturation 98% on room air. EKG showed sinus rhythm with premature atrial complexes and shortened QT interval (corrected 376ms).
Laboratory investigations were significant for normocytic anemia with a hemoglobin of 9.8 g/dL, leukopenia 3.3 x 103/microL, thrombocytopenia 120 x 103/microL, BUN 43 mg/dL (RI 8-20mg/dL), creatinine 2.09 mg/dL (RI 0.4-1.3 mg/dl), corrected calcium 16.49 mg/dL (RI 8.9-10.3 mg/dL), ionized calcium 7.8 mg/dL (RI 4.5-5.6 mg/dL), phosphorus 4.4 mg/dL (RI 2.4-4.7 mg/dL), and albumin 2.6 g/dL (RI 3.5-4.8 g/dL). Other notable initial laboratory findings included 25-hydroxyvitamin D level 56 ng/ml (RI 30-100 ng/ml), 1,25 dihydroxyvitamin D level 44.1 pg/ml (RI 19.9-79.3 pg/ml), parathyroid hormone (PTH) 4 pg/mL (RI 15-65 pg/mL) with PTH-related peptide levels undetectable. Of note, CD4 count was 36/mm3 and viral load was 617,000 before initiation of antiretroviral therapy.
He received intravenous fluids and pamidronate with calcitonin. His serum calcium declined to 9.8 mg/dL (RI 8.9-10.3 mg/dL), kidney function improved with BUN 39mg/dL (RI 8-20mg/dL) and creatinine 1.26 mg/dL (RI 0.4-1.3 mg/dl) by hospital day three. There was improvement in patient's mental status within one day of treatment initiation.
Serum protein electrophoresis revealed monoclonal gammopathy with Free Kappa/Lambda ratio of 1.31 (0.26-1.65) and serum Monoclonal Immunoglobulin (Ig) G was also elevated at 2359. Lactate dehydrogenase level (LDH) was 281 IU/L (RI 98-192 IU/L) and beta-2- microglobulin was 12 mg/L (RI 0.6-2.4mg/L). Whole body skeletal survey revealed no focal uptake. There was no evidence of parenchymal lung disease or mediastinal lymphadenopathy on Computerized Tomography (CT) scan of Chest (Figure 1). CT scan of Abdomen and Pelvis revealed hepatosplenomegaly with large retroperitoneal, retrocrural, and mesenteric lymphadenopathy (Figure 2(a,b)) which had an intense focal uptake on Gallium scan with no abnormal lung uptake (Figure 3). The presence of Monoclonal IgG along with hepatosplenomegaly and retroperitoneal lymphadenopathy, elevated LDH were all strongly suggestive of initial presumptive diagnosis of a lymphoproliferative disease. Lymphoma was strongly suspected and he underwent a bone marrow biopsy and lymph node biopsies twice. Bone marrow biopsy revealed mild plasmacytosis (5%), normocellular marrow (50%) with mature trilineage, no evidence of myelodysplasia, acute leukemia or lymphoma. A subsequent biopsy of the lymph nodes showed fragments of fibrous tissue with lymphohistiocytic infiltrate (Figure 4) and many acid-fast bacilli on special stain (Figure 5). Results of bone marrow biopsy and lymph node biopsy were not consistent with lymphoma which promoted investigation for other causes of hypercalcemia and lymphadenopathy. Mycobacterium tuberculosis and Mycobacterium avium complex Polymerase Chain Reaction (PCR) were also negative. Three sputum samples for acid fast bacilli (AFB) smear were negative.
Patient was initially started on Vancomycin and meropenem for presumed sepsis. As lymph node biopsy smear was positive for AFB; rifabutin, isoniazid, pyrazinamide and ethambutol were commenced as well as azithromycin for tuberculous and nontuberculous mycobacterium pending further identification. Calcium level remained within normal range and his medical condition improved. He was then discharged with medical follow up and continues to show sustained clinical improvement. However, pre-antibiotic blood cultures drawn in a sodium heparin tube subsequently grew Mycobacterium identified by genomic analysis as M. abscessus subspecies abscessus at four weeks. Bone marrow culture remained without any growth.
Chest CT scan- Axial view: Normal parenchymal lung tissue without evidence of active chest disease or intrathoracic lymphadenopathy.