Isolated Thrombocytopenia as the Initial and Sole Manifestation of Bone Marrow B-Cell Lymphoma in an Elderly Female.

B-cell lymphomas are highly aggressive forms of lymphoma that commonly present with lymphadenopathy, systemic "B" symptoms, or organ involvement making them easy to recognize; however, a small percentage of B-cell lymphomas can present without any typical symptoms or evidence of lymphadenopathy, resulting in delayed recognition and management. Isolated thrombocytopenia without anaemia or leukopenia is an unusual presentation of B cell lymphomas and may be misdiagnosed as immune thrombocytopenia (ITP). Given the rarity of this presentation, we wish to report a case of a 76-year-old female who presented with palpitations, shortness of breath, and recurrent chest infections. She was found to have isolated thrombocytopenia (platelet count 57 ×10⁹/l) with otherwise normal laboratory findings. Initial treatment for presumed ITP was unsuccessful, which lead to more invasive investigations. Bone marrow biopsy revealed infiltration with atypical lymphoid nodules consistent with B-cell non-Hodgkin lymphoma. Following chemotherapy, her platelet counts normalized. This case highlights the importance of bone marrow evaluation in elderly patients with unexplained thrombocytopenia, even in the absence of typical lymphoma features.

Learning points: This case demonstrates absence of lymphadenopathy or systemic symptoms does not exclude bone marrow infiltration by lymphoma.Early recognition and accurate diagnosis of atypical lymphoma presentations are essential to avoid treatment delays and improve patient outcomes.Bone marrow biopsy plays a crucial role in diagnosing occult B-cell lymphoma in cases lacking systemic symptoms or lymphadenopathy.