Differential Diagnosis for Patient with Polymyalgia Rheumatica and Lymphocytosis
Single most likely diagnosis:
- B. CLL (Chronic Lymphocytic Leukemia): This is the most likely diagnosis given the patient's presentation with B symptoms (such as fever, night sweats, and weight loss) and a bone marrow biopsy showing a large lymphocyte count. CLL is a type of cancer that affects the blood and bone marrow, characterized by the production of an excessive number of immature white blood cells, known as lymphocytes.
Other Likely diagnoses:
- C. GCA (Giant Cell Arteritis): While GCA is closely related to polymyalgia rheumatica (PMR) and can present with similar symptoms, the presence of B symptoms and lymphocytosis on bone marrow biopsy leans more towards a hematological malignancy rather than GCA alone. However, it's possible for GCA/PMR to coexist with other conditions.
- A. CML (Chronic Myeloid Leukemia): CML is another type of leukemia that could present with an increased white blood cell count, but it typically shows a left-shifted myeloid series on the peripheral blood smear and bone marrow, rather than a predominance of lymphocytes.
Do Not Miss diagnoses:
- D. AML (Acute Myeloid Leukemia): Although less likely given the description of "large lymphocyte count," AML is a critical diagnosis not to miss due to its aggressive nature and need for prompt treatment. AML can present with a variety of symptoms, including B symptoms, and while the bone marrow findings would typically show a predominance of myeloblasts, some subtypes could potentially be considered in the differential.
Rare diagnoses:
- Other lymphoproliferative disorders: These could include conditions like lymphoma (Hodgkin or non-Hodgkin), which might present with lymphocytosis and systemic symptoms. However, these would be less common than CLL in this context and might require additional diagnostic testing for confirmation.
- Rheumatological conditions with secondary hematologic findings: Certain autoimmune or rheumatological conditions can have associated hematologic abnormalities, including lymphocytosis, but these would be less likely given the specific findings of B symptoms and a significant lymphocyte count on bone marrow biopsy.