Case Presentation: A 32-year old female with complicated past medical history of intravenous drug use, mitral valve endocarditis status/post repair, and recent diagnosis of Immune thrombocytopenia (ITP) was transferred from another hospital for management of severe thrombocytopenia refractory to Intravenous Immunoglobulin (IVIG) and steroids. She had initially presented with intermittent high-grade fevers and fatigue without associated arthralgia or dyspnea. She was found to have labs significant for pancytopenia with white blood cell count of 3000/microliter, hemoglobin of 8 gram/deciliter and platelets of 4000/microliter (prior admission labs 3 months with similar labs except for platelets of 174 thousand), reticulocyte proliferative index 1.30, unremarkable hemolysis labs. Of note, prior to the current admission, she recently had a bone marrow (BM) biopsy to work up her thrombocytopenic episodes, which was significant for non-caseating granulomatous inflammation. Her vital signs on arrival were stable. Her physical exam was notable for lungs with bibasilar crackles, generalized abdominal tenderness more prominent on left side and petechiae on all extremities. Imaging of her chest, abdomen and pelvis was unremarkable except for noted hepatosplenomegaly. Peripheral smear was negative for schistocytes. As per Hematology recommendations, patient was started on solumedrol 60 mg twice daily and given a second dose of IVIG. Patient’s platelets increased to 18,000 but did not sustain. Extensive infectious evaluation was negative, including parasite work-up and blood cultures. Trans-thoracic echocardiogram was negative for vegetations. Due to suspicion for connective tissue disorder (CTD) based on prior BM biopsy, rheumatology was consulted. Extensive rheumatologic workup was notable for elevated RF (320) and angiotensin converting enzyme (ACE) 94 along with low C3 (51) and C4 (7) complements and vitamin D25 (14). All other workup including immunofixation, other CTD antibodies and ANCA panel were negative. There was a high concern for BM sarcoidosis after review of the BM biopsy in the setting of low vitamin D25, elevated ACE level and negative workup for other diseases. With no significant increase in platelets with IVIG and steroids, patient was started on Rituximab resulting in favorable response. After a multi-interdisciplinary discussion, it was noted that the patient likely has secondary ITP from underlying bone marrow sarcoidosis.
Discussion: Severe thrombocytopenia is a rare presentation of sarcoidosis. Three possible mechanisms are generally stated to cause thrombocytopenia in sarcoidosis – 1) sequestration in spleen 2) bone marrow involvement 3) autoantibody production [2,3]. All three mechanisms are likely contributing to the patient’s severe thrombocytopenia, which is why secondary ITP was considered in this patient. ITP secondary to sarcoidosis is treated similar to primary ITP [1].
Conclusions: Sarcoidosis is a disease known to commonly affect the pulmonary and musculoskeletal system. Bone marrow involvement with severe thrombocytopenia is an uncommon presentation of sarcoidosis, making it difficult to recognize in the inpatient setting. In a patient with refractory thrombocytopenia, rheumatologic diseases such as sarcoidosis should always be considered as a possible underlying etiology. This case highlights both the difficulty and importance in identifying bone marrow involvement of sarcoidosis in order to provide appropriate management.