Routine bone marrow biopsy in the initial evaluation of primary cutaneous B-cell lymphoma does not appear justified

Primary cutaneous B-cell lymphomas are a rare entity. They are included in the distinct classification of primary cutaneous lymphomas, the WHO-EORTC. In order to be confirmed, the primary nature of a cutaneous lymphoma requires that negative results of a CT scan of the chest, abdomen and pelvis and of a bone marrow biopsy (BMB) be obtained. Nevertheless, there is a question as to whether BMB should be performed routinely in view of the good prognosis of certain cutaneous B-cell lymphomas and the invasive nature of the examination. To answer that question, we studied retrospectively 62 cases of cutaneous B-cell lymphomas in which a BMB was performed. In 4 cases, lymph nodes, and in one case pancytopenia were identified during the initial evaluation performed at the same time as BMB and thus these patients were excluded from the analysis. Among the 57 patients, the BMB was positive in only 3 patients (5.2%). Interestingly, the positivity of the biopsy did not significantly affect the way that the treatment was given. In conclusion, this study demonstrates that it is not indispensable to perform a routine BMB for a Primary cutaneous B-cell lymphoma with cutaneous lesions on examination and with negative CT Scan and blood laboratory evaluations.