Tc-99m Sulfur Colloid Bone Marrow Scintigraphy in Diagnosis of Diffuse Pulmonary Extramedullary Hematopoesis Secondary to Myelofibrosis: Experience of a Tertiary Hospital

Abstract

Objective: To define the role of combined Tc-99m sulfur colloid bone marrow (SC BM) scintigraphy, single-photon emission computed tomography (SPECT/CT), and chest CT in diagnosing diffuse pulmonary extramedullary hematopoiesis (PEMH) in patients with myelofibrosis (MF). Methods: We retrospectively reviewed Tc-99m SC BM scintigraphy scans performed at our institution for the diagnosis of diffuse PEMH, as well as accompanying chest CT and SPECT/CT imaging findings. Relevant clinical information, including respiratory manifestations, pulmonary hypertension (PH), and subjective response to whole-lung radiation therapy, was also summarized. Results: Twenty-two MF patients with 27 Tc-99m SC BM scintigraphy scans were diagnosed with diffuse PEMH. In 21 (95%) patients with accompanying chest CT and SPECT/CT scans, the most common CT findings were ground-glass opacity, interstitial infiltration, and pleural effusion. Of 20 patients (91%) who underwent 2-dimensional echocardiography studies, 12 (55%) were diagnosed with PH. All 12 patients exhibited the aforementioned nonspecific CT imaging findings with 8 (66%) of them presented with respiratory symptoms, including dyspnea, shortness of breath, and cough. In the remaining 8 patients without PH, half had similar respiratory symptoms. Fourteen patients (64%) of this cohort received whole-lung radiation therapy, of whom 7 (50%) experienced symptom relief after therapy. Conclusion: Nonspecific respiratory symptoms should raise concern for PH and diffuse PEMH in patients with advanced-stage MF. Combined Tc-99m SC BM scintigraphy and SPECT/CT is a promising noninvasive imaging tool to diagnose this rare clinical entity.