LAUSR

Case A 15‐year‐old male presented with gross proptosis of right eye for the past 3 weeks. On presentation, visual acuity in the right eye was just perception of light while it was 20/20 in the left eye. Right eye was grossly proptosed with severe exposure keratopathy and surrounding conjunctival chemosis [Fig. 1a]. A firm mass was palpable in the superior quadrant of the orbit. Computed tomography scan was suggestive of bilateral well‐defined isodense mass lesion in the superior extraconal space with dural‐based masses in the frontal and parietal lobes [Fig. 1b]. Patient had been extensively investigated 2 weeks back by a local ophthalmologist and the blood investigation revealed severe microcytic hypochromic anemia (hemoglobin 6 gm/dl). However, there were no abnormal white blood cells in the peripheral smear. What is Your Next Step? A. Refer the patient to a hematologist to build up hemoglobin and plan for incisional biopsy B. Urgent incisional biopsy under local anesthesia C. Bone marrow biopsy D. Repeat peripheral blood smear Findings Repeat peripheral bloods smear revealed blast cells with multiple nucleoli and Auer rods suggestive of acute myeloid leukemia [Fig. 2a and b]. The patient was referred to a hematooncologist for further management. Diagnosis Orbital granulocytic sarcoma Correct Answer: D. Discussion Granulocytic sarcoma is a childhood malignancy mostly seen in less than 10 years of age. It is seen in 3–5% of patients with acute myeloid leukemia (AML).[1] When granulocytic sarcoma occurs in the absence of AML (aleukemic leukemia), it is known as de novo granulocytic sarcoma.[1] De novo orbital granulocytic sarcoma is rare, and in all such cases, both the peripheral blood smear and bone marrow biopsy are normal, while biopsy from the orbital mass suggests granulocytic sarcoma.[2,3] Although the mean duration after which leukemia develops in a case of de novo granulocytic sarcoma has been reported to be 10.5 months,[4] it is always advisable to repeat the peripheral blood smear in all cases where the index of suspicion is high even if the report had been normal in the recent past. This simple test precludes the need of an orbital biopsy.