Blood Cell Count Abnormalities Might Indicate Bone Marrow Involvement in Sarcoidosis, Report Suggests

Alterations in the blood cell count of people with sarcoidosis might indicate that the disease has invaded the bone marrow, a case report suggests. Doctors should therefore consider this clinical sign to aid in early diagnosis and avoid further complications.

The study, “Bone marrow involvement in sarcoidosis: an elusive extrapulmonary manifestation,” was published in the Journal of Community Hospital Internal Medicine Perspectives.

Sarcoidosis can affect many organs and therefore has multiple manifestations, making it difficult to diagnose. In over 90% of cases, the disease affects the lungs, but it can also manifest in areas including the liver, heart, gut, and bones.

In approximately 10% of cases, sarcoidosis affects the bone marrow, altering the numbers of different blood cells and causing symptoms including enlarged spleen, weight loss, fever, and fatigue.

Researchers reported the case of a 51-year-old African-American woman who had previously been diagnosed with sarcoidosis in the skin (cutaneous sarcoidosis) that later affected the bone marrow and lungs.

The patient presented to the hospital because she had had burning pain below her knee for two weeks. She also had a mild fever, chronic dry cough, and reduced appetite, and had involuntary lost 30 pounds over the last two years. Her vital signs were normal.

Lab exams showed reduced white and red blood cell counts, iron deficiency, borderline anemia, increased levels of inflammatory blood cells, and elevated inflammatory markers such as C-reactive protein.

A physical examination and imagining tests showed that the patient had a nodule in the lung, abnormal-sized lymph nodes, and enlarged liver and spleen. These symptoms suggested that the sarcoidosis that initially affected only the skin had progressed to other organs.

The diagnosis was confirmed when doctors observed granulomas — clumps of inflammatory cells characteristic of sarcoidosis — in the patient’s lung and bone marrow biopsies. The team also looked for signs of sarcoidosis in the nervous system, but did not find any.

The patient was then treated with oral prednisone, a corticosteroid that prevents inflammation and suppresses the immune system.

“To the best of our knowledge, there are no randomized controlled trials comparing different therapeutic strategies for [bone marrow sarcoidosis]. Prednisone remains the mainstay of treatment,” the team stated.

Based on this case report, researchers highlighted the importance of monitoring the progression of sarcoidosis and looking for secondary symptoms, because in this case a lack of follow-up might have allowed the disease to spread from the skin to other organs.

According to the team, bone marrow sarcoidosis “represents an infrequent manifestation of extrapulmonary sarcoidosis, and is more prevalent in women and African-Americans. Unexplained cytopenias [blood cell alterations], although nonspecific, may be a solitary finding, and thus clinicians should maintain a high index of suspicion.”