Unusual lower back pain with monocytosis: A case report.

There are numerous causes of lower back pain. In the oncological setting, spine metastasis from a solid tumor is the most common. However, hematological disorders should also be taken into consideration. The current study presents a case of chronic myelomonocytic leukemia with the initial presentation of chronic lower back pain, followed by symptoms that included urinary retention, stool incontinence and left gum swelling, in a patient who was eventually diagnosed with granulocytic sarcoma (GS) over the sacral region. GS is a rare presentation of a tumor consisting of extramedullary leukemic infiltrations, which develop at different sites and cause different symptoms. Prompt and correct diagnosis of this type of disease may be crucial to improve the survival outcome by the early initiation of adequate treatment.