Case Presentation: Bone marrow sarcoidosis along renal involvement is extremely rare and diagnosis can be a challenge. Here we report a rare occurrence of sarcoidosis presenting as anemia and Acute Kidney Injury (AKI) without pulmonary involvement.
Case Report
A 27-year-old female was admitted to hospital with fatigue, abdominal pain, and generalized weakness. Past medical history was significant for Graves’ disease, undergone thyroidectomy. She denied fever, chills, menorrhagia and blood in stools. Pallor was noted on examination without evidence of hepato-splenomegaly or lymphadenopathy. Lab work demonstrated acute normocytic anemia with hemoglobin (Hb) of 7.5 g/dl and AKI with creatinine of 5 mg/dl compared to normal Hb and renal function a month prior. Lab tests also revealed normal iron (30 ug/dl), total iron binding capacity (293 ug/dl), elevated ferritin (394 ng/ml), mildly decreased iron saturation (12.9%), normal lactate dehydrogenase (188U/L), normal haptoglobin (186 mg/dl), and total bilirubin (0.2 mg/dl) consistent with anemia of chronic disease without hemolysis. Vitamin B12, folate and thyroid stimulating hormone levels were normal. Urinalysis negative for hematuria or proteinuria. Autoimmune work-up including ANA, double stranded DNA (19 IU/ml), rheumatoid factor (12 IU/ml) and ANCA were normal. Serum and urine protein electrophoresis was negative for multiple myeloma. Peripheral blood flow cytometry did not support the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) and furthermore, cold agglutinin and Parvovirus IgM titers were negative.
Non-contrast CT Chest, Abdomen and Pelvis was negative for pulmonary mass or mediastinal lymphadenopathy, revealed normal spleen, liver and kidneys respectively. Hence, a bone marrow aspiration and biopsy was obtained, showed extensive non-caseating granulomata, with no evidence of lymphoma, suggestive of sarcoidosis. A renal biopsy was also obtained, consistent with chronic granulomatous interstitial nephritis. Biopsies were negative for infectious organisms. A final diagnosis of sarcoidosis with bone marrow and renal involvement without pulmonary manifestations was made. Angiotensin converting enzyme levels (ACE) and serum soluble interleukin-2 receptor (sIL-2R) were obtained, showed normal ACE levels (45 U/L) and elevated sIL-2R (3,650 U/ml; normal 223-710 U/ml). Prednisone slow taper 40mg daily was started, with improving creatinine (1.6 mg/dl) and hemoglobin (11.8 g/dl) one month later.
Discussion: Sarcoidosis is a chronic multi system disease of unknown etiology, characterized by non caseating granuloma of the involved organ. Bone marrow and renal involvement of sarcoidosis is rare. One case series reports 10% of patients had granulomata in the bone marrow. Awareness of the common and protean manifestations of sarcoidosis is required to recognize the disease and monitor for additional disease complications.
Conclusions: While bone marrow involvement with renal failure are the rare initial presentations, a high suspicion for sarcoidosis is warranted in patients with atypical presentation.
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