A 54-year-old previously healthy gentleman presented with 1-month history of persistent low back pain. The pain started suddenly, was dull in nature, non-radiating, and worse during the night. No alleviating or exacerbating factors. While he denied symptoms of urinary incontinence, saddle anesthesia, or peripheral numbness, he reported an occasional cough that was present since 1 year prior to presentation.
Blood investigations were significant for ACE level of 102.2 U/L (reference: 12-68 U/L). Erythrocyte sedimentation rate (ESR) was elevated at 79 mm/h and C-reactive protein (CRP) was elevated at 52 mg/L. Complete blood count, electrolytes, calcium, hemoglobin A1c, fasting blood sugar, and lipid profile were within normal limits.
A magnetic resonance imaging (MRI) of the lumbar spine showed diffuse metastatic osteolytic bone disease in the lumbar and dorsal spine with L5-S1 degenerative disk disease impinging on the S1 nerve root.
A positron emission tomography (PET) scan showed radiotrace avid liver lesions with multiple bilateral fluorodeoxyglucose (FDG) avid pulmonary nodules. Enlarged mediastinal, bilateral hilar, bilateral axillary, abdominal, and pelvic lymph nodes were noted (Figure 1A to D). In addition, thickened left adrenal gland showing diffuse increased radiotracer uptake indicating likely disease involvement was noted. Furthermore, multiple lytic bone lesions, involving the axial and appendicular skeleton, the skull, ribs, and pelvic bones were evident. An ultrasound guided liver needle core biopsy was performed without evidence of malignancy. The liver was almost completely replaced by back to back non-caseating granulomas (Figure 2A). These granulomas were small and composed of tightly packed epithelioid histiocytes without associated necrosis, caseation, or acute inflammation (Figure 2B). Rare Langerhans-type multi nucleated giant cells were noted (Figure 2C). There were no Schaumann or Asteroid bodies noted in the giant cells. The granulomas were present in the hepatic parenchyma and also adjacent to bile ducts. Periodic acid-Schiff (PAS) and Grocott's methenamine silver (GMS) stains were negative for fungal organisms. Acid fast stain was negative for mycobacterium tuberculosis. The biopsy ruled out a malignant condition and was most consistent with sarcoidosis. However, other granulomatous conditions were entertained, such as tuberculosis, atypical mycobacteria, fungal infections, sarcoid-like lesions due to cancer, immunodeficiency or medications, heavy metal, and others.
Subsequently, a computed tomography (CT) of the chest without contrast was positive for diffuse lung nodule pattern with dispersed lesions seen with mean 5 mm mostly compatible with sarcoidosis. Sub-axillaries and mediastinum small lymph nodes were noted.
As the patient was not severely symptomatic, he was started on prednisone 20 mg daily for 1 week to be tapered by 5 mg weekly. In a 2-month post-treatment visit, the patient reported a significant improvement in the back pain, but slight improvement of the cough.