Diffuse Bone Marrow Uptake on F-18 FDG PET in Patients With Myelodysplastic Syndromes

Diffuse bone marrow uptake on 18F-fluorodeoxyglucose positron emission tomography/computed tomography with copper-deficiency anemia

A 59-year-old man with pancytopenia underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography for suspected carcinomatosis. The scan revealed diffuse bone marrow uptake, prompting further investigation. Bone marrow analysis revealed no malignant cells; however, erythroblasts with cytoplasmic vacuolization were observed. Subsequent testing showed low serum copper and ceruloplasmin levels, indicating copper deficiency. Copper supplementation resulted in significant improvement in cytopenia. Notably, the bone marrow uptake on subsequent scans decreased significantly. This case highlights the importance of considering copper deficiency as a potential cause of diffuse bone marrow uptake of 18F-fluorodeoxyglucose on positron emission tomography/computed tomography.

A "Leopard Man" Aspect on 18 F-FDG PET/CT Revealing a VEXAS Syndrome

ABSTRACT

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is an adult-onset autoinflammatory disease caused by somatic UBA1 mutations first described in 2020. Most of these patients met clinical criteria for an inflammatory syndrome (relapsing polychondritis, Sweet syndrome, polyarteritis nodosa, or giant-cell arteritis) or a hematologic condition (myelodysplastic syndrome or multiple myeloma) or both. We described here an FDG PET/CT "leopard man" appearance, with abnormal marrow recruitment the findings, in a 70-year-old man diagnosed with a VEXAS syndrome.

Disseminated focal 18F-fluoro-deoxyglucose uptake upon granulocyte colony-stimulating factor therapy mimicking malignant bone infiltration: case report of a patient with very severe aplastic anemia

Combined ¹⁸F-fluoro-deoxyglucose ([18F]FDG) positron emission tomography and computed tomography ([18F]FDG-PET/CT) is increasingly used for the diagnostic and therapeutic management of hematologic and non-hematologic malignancies. Here, we describe a unique case of a patient presenting with very severe aplastic anemia and a mediastinal mass showing disseminated hypermetabolic lesions of the bones after receiving granulocyte colony-stimulating factor (G-CSF), highly suspicious for disseminated metastatic lesions. A 71-year-old patient presented with a 3 week history of dyspnea and fatigue. Blood tests showed severe pancytopenia and iliac crest bone marrow biopsy revealed an extensively hypoplastic bone marrow. Diagnostic work-up by histology, conventional cytogenetics and flow cytometry confirmed the diagnosis of very severe aplastic anemia. Besides blood transfusions, the patient was treated with G-CSF. Furthermore, computed tomography revealed a suspect mass in the anterior mediastinum, presenting with moderate glucose metabolism in the subsequent [18F]FDG-PET/CT scan. In addition, multiple disseminated and highly metabolic bone lesions of primarily the ribs were detected, suspicious of malignant bone infiltration. Since physiologic bone marrow activation by G-CSF-stimulation could not be ruled out, G-CSF therapy was interrupted to repeat the PET/CT scan 10 days later. On the second [18F]FDG-PET/CT the moderately hypermetabolic mediastinal mass persisted. However, the initially FDG-avid bone lesions almost completely resolved, rendering the diagnosis of G-CSF-induced bone marrow hypermetabolism very likely without the need for further invasive diagnostic procedures. The mediastinal mass was thereafter histologically verified as thymoma. Interpretation of [18F]FDG-PET/CT in patients with aplastic anemia may be complicated by the frequent therapeutic use of G-CSF. With G-CSF, islets of residual bone marrow activity can be visualized on [18F]FDG-PET/CT images that might be misinterpreted as malignant bone infiltration. Repeating PET/CT scan after G-CSF discontinuation can prevent unnecessary invasive diagnostic procedures in these patients.

Bone marrow uptake of 18F-fluorodeoxyglucose in Hodgkin lymphoma without bone involvement: comparison between patients with and without B symptoms

Objective

To compare the degree of benign bone marrow uptake of ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) between Hodgkin lymphoma patients with and without B symptoms.

Materials and Methods

We analyzed the medical charts of 74 Hodgkin lymphoma patients who underwent ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) prior to the initiation of therapy between October 2010 and September 2013. In all of the patients, the bone marrow biopsy was negative and the ¹⁸F-FDG PET/CT images did not suggest bone marrow involvement. Of the 74 patients evaluated, 54 presented inflammatory (B) symptoms and 20 did not. Regions of interest (ROIs) were drawn on the sternum, the proximal thirds of the humeri, the proximal thirds of the femora, and both iliac wings (totaling seven ROIs per patient). To compare the patients with and without B symptoms, in terms of standardized uptake values (SUVs) for the seven ROIs, we used the Mann-Whitney U test.

Results

For six of the ROIs, the SUVs were higher in the patients with B symptoms than in those without, and the difference was statistically significant (p < 0.05). There was also a tendency toward a statistically significant difference between the two groups in terms of the SUV for the right iliac wing ROI (p = 0.06).

Conclusion

In our sample, the presence of B symptoms was associated with increased ¹⁸F-FDG uptake in bone marrow.

[Large vessel vasculitis with myelodysplastic syndrome: A rare association]

INTRODUCTION

The vasculitis can be the consequence of malignancy: most often hematologic rather than solid tumors. The association between large vessels vasculitis and myelodysplastic syndrome is rare.

CASE REPORT

A 55-year-old man experienced asthenia, fever, polyarthritis and inflammatory syndrome. Haematological investigations found a type 2 refractory anemia with excess blasts (RAEB-2) with discovery of severe anemia (Hb: 7,8g/dl) and thrombopenia (platelets: 40,000/mm³). Radiological examinations found thoracic aortitis and carotid vasculitis. Treatment in the form of steroids and azacitidine was instituted. The lack of control of both RAEB-2 and vasculitis was responsible for the death of the patient.

CONCLUSION

Myelodysplastic syndrome and large vessels vasculitis is a rare but serious association disease. The lack of efficiency of corticosteroids seems to be common. Prognosis depends on the haematological treatment effectiveness.

FDG-PET/CT findings in systemic mastocytosis: a French multicentre study

INTRODUCTION

Mastocytosis is a clonal haematological disease characterized by uncontrolled proliferation and the activation of mast cells. The value of FDG-PET/CT (FDG-PET) in mastocytosis has yet to be determined.

METHODS

We retrospectively identified patients with an established diagnosis of systemic mastocytosis (SM), according to the WHO criteria, who underwent PET using the French Reference Centre for Mastocytosis database. Semi-quantitative and visual analysis of FDG-PET was performed and compared to the clinico-biological data.

RESULTS

Our cohort included 19 adult patients, median age 65 years [range 58-74], including three with smouldering SM (SSM), three with aggressive SM (ASM), 10 with an associated clonal haematological non-mast-cell lineage disease (SM-AHNMD), and three with mast cell sarcoma (MCS). FDG-PET was performed at the time of the SM diagnosis (15/19), to evaluate lymph node (LN) activity (3/19) or the efficacy of therapy (1/19). FDG uptake was observed in the bone marrow (BM) (9/19, 47%), LN (6/19, 32%), spleen (12/19, 63%), or liver (1/19, 5%). No significant FDG uptake was observed in the SSM and ASM patients. A pathological FDG uptake was observed in the BM of 6/10 patients with SM-AHNMD, appearing as diffuse and homogeneous, and in the LN of 5/10 patients. All 3 MCS patients showed intense and multifocal BM pathological uptake, mimicking metastasis. No correlation was found between the FDG-PET findings and serum tryptase levels, BM mast cell infiltration percentage, and CD30 and CD2 expression by mast cells.

CONCLUSIONS

FDG uptake does not appear to be a sensitive marker of mast cell activation or proliferation because no significant FDG uptake was observed in most common forms of mastocytosis (notably purely aggressive SM). However, pathological FDG uptake was observed in the SM-AHNMD and in MCS cases, suggesting a role of FDG-PET in their early identification and as a tool of therapeutic assessment in this subgroup of patients.

18F-FDG PET/CT findings in a patient with Sweet syndrome associated with myelodysplastic syndrome

A 73-year-old man was admitted to our hospital because of a 2-year history of repeated painful edematous erythemas on the skin and pancytopenia for the last 8 months. FDG PET/CT demonstrated multiple cutaneous foci with increased tracer accumulation throughout the body, multiple FDG-avid lymph nodes in the mediastinum, bilateral pulmonary hili and abdomen, and diffusively increased FDG uptake of bone marrow. A skin biopsy revealed infiltration by neutrophilic granulocytes consistent with Sweet syndrome. Myelodysplastic syndrome was established on bone marrow aspiration and biopsy.

Diffuse homogeneous bone marrow uptake of FDG in patients with acute lymphoblastic leukemia

PET (positron emission tomography) using FDG (¹⁸F-fluorodeoxyglucose) has been widely used in the evaluation of various malignancies, but its clinical application to leukemia remains limited. We report a case of leukemia in which diffuse bone marrow uptake of FDG was observed, and bone marrow aspiration subsequently revealed acute lymphoblastic leukemia. It is not easy to differentiate between physiological and pathologic uptake when diffuse homogeneous uptake in bone marrow is observed.

Chronic myeloid leukemia detected on FDG PET/CT imaging in a patient with renal cell carcinoma

It is well known that hematopoietic cytokine stimulation can cause increased fluorodeoxyglucose (FDG) accumulation in bone marrow on PET/CT imaging, which simulates that seen in patients with bone marrow metastases. However, increased bone marrow FDG uptake can be caused by other etiologies. We report a patient with operated renal cell carcinoma had no history of hematopoietic cytokine stimulation. The FDG PET/CT images showed increased bone marrow FDG uptake, and the patient was diagnosed as chronic myeloid leukemia. This case revealed that increased FDG uptake on bone marrow may be related to neoplastic disease of the hematopoietic tissues.

Unexpected primary osseous lymphoma as the cause of lactic acidosis in a patient suffering from pancreatitis

A 45-year-old man was admitted due to acute pancreatitis. A severe lactic acidosis was found. Following active therapy, the signs and symptoms from pancreatitis was improved, but acidosis was exacerbated. FDG PET/CT images were acquired to investigate the etiology of lactic acidosis and/or other unknown pathology. The images showed widespread abnormal FDG activity in the bone marrows throughout the body, suggestive of hematologic malignancy, which was confirmed as primary osseous non-Hodgkin lymphoma following a histopathological examination of the bone marrow. Chemotherapy against lymphoma was initiated and status of the lactic acidosis was rapidly corrected.

Physiology and pathophysiology of incidental findings detected on FDG-PET scintigraphy

A routine feature of positron emission tomography/computed tomography (PET/CT) imaging is whole-body acquisition that results in many unexpected findings identified outside of the primary region of abnormality. Furthermore, (18)F-fluorodeoxyglucose (FDG) is a marker of glycolysis and does not specifically accumulate in malignancy. Understanding the physiology and pathophysiology of normal FDG distribution and common incidental findings is therefore essential to the physician interpreting whole-body FDG-PET/CT studies. Whereas many incidental findings are benign and of limited clinical significance, others represent uncommon manifestations of the primary malignancy, second malignancies, or various clinically significant pathologic processes. Patients with a single malignancy are at greater risk of developing synchronous or metachronous second malignancies, possibly related to exposure to shared carcinogenic agents or presence of prooncogenic mutations. The decision of how to pursue an intervention on the basis of an incidental finding is generally left to clinical judgment.

Radionuclide imaging of bone marrow disorders

Noninvasive imaging techniques have been used in the past for visualization the functional activity of the bone marrow compartment. Imaging with radiolabelled compounds may allow different bone marrow disorders to be distinguished. These imaging techniques, almost all of which use radionuclide-labelled tracers, such as ^99mTc-nanocolloid, ^99mTc-sulphur colloid, ¹¹¹In-chloride, and radiolabelled white blood cells, have been used in nuclear medicine for several decades. With these techniques three separate compartments can be recognized including the reticuloendothelial system, the erythroid compartment and the myeloid compartment. Recent developments in research and the clinical use of PET tracers have made possible the analysis of additional properties such as cellular metabolism and proliferative activity, using ¹⁸F-FDG and ¹⁸F-FLT. These tracers may lead to better quantification and targeting of different cell systems in the bone marrow. In this review the imaging of different bone marrow targets with radionuclides including PET tracers in various bone marrow diseases are discussed.

Hyperostosis - an unusual radiographic presentation of Myelodysplastic Syndrome transformed to Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is also referred to non-lymphocytic leukemia in the literature. It comprises about 15% of the childhood leukemia. There are multiple subtypes of AML from M0-M7 with approximately 45% of the cases being M0-M2 and the remaining subtypes being rare. The definitive diagnosis relies on bone marrow biopsy showing bone marrow infiltration with leukemic cells. We describe a rare radiographic presentation of myelodysplastic syndrome (MDS) transformed to AML in an 8 month old boy who presented with a orbital wall fracture, periosteal reaction, and mixed lytic and sclerotic lesions.

High F-18 FDG uptake in bone marrow by cytokines secreting ectopic mucoepidermoid carcinoma

A 57-year-old woman, just returned from a bicycling holiday in the mountains, presented with discomfort, hoarseness and chronic cough complaints. After chest x-ray, bronchoscopy and fluoro-deoxy-glucose positron emission tomography/computed tomography (F-18 FDG PET/CT), a diagnosis of a tumor in the bronchus of the right upper lobe with obstruction pneumonia was made. After lobectomy of the right upper lobe, pathology revealed an ectopic bronchial low-grade mucoepidermoid carcinoma.The diffuse high FDG uptake in the bone marrow standardized uptake value (SUV mean 3.6 and max 5.2) is unlikely to be related to bone marrow stimulation due to pneumonia, but correlates with a high serum level of correlated with transforming growth factor-beta (TGF-beta1) secreted by the low-grade bronchial mucoepidermoid carcinoma.

[Extramedullary blastic transformation revealed by a prolonged fever during the course of a 5q- syndrome]

INTRODUCTION

Fever during a myelodysplastic syndrome can be due to infectious complications, systemic disease or acute transformation with clonal evolution.

CASE REPORT

A 51-year-old woman, with a 5q- syndrome and neutropenia, presented with a several week fever duration. Infectious work-up was negative and therapy with antibiotics had no influence on the clinical course. Neither bone marrow nor blood blasts were detected, but liver biopsy demonstrated significant blast infiltration compatible with the diagnosis of acute myeloid leukaemia (AML).

CONCLUSION

The absence of blasts in blood or bone marrow does not exclude the malignant transformation of a myelodysplastic syndrome to AML. Tissue biopsy may be necessary to confirm the leukaemic progression.

A bone marrow F-18 FDG uptake exceeding the liver uptake may indicate bone marrow hyperactivity

OBJECTIVE

In clinical positron emission tomography (PET) studies for oncology, it is occasionally required to differentiate a diffuse increase in bone marrow (BM) F-18 fluoro-2-deoxyglucose (FDG) uptake due to the involvement of malignancy or hematopoietic disease and that due to the administration of hematopoietic cytokines, an inflammation reaction, or stimulation by some types of malignancy. The objectives of this study were to clarify the relationships between BM F-18 FDG uptake and blood parameters as well as age, and also to determine the degree of F-18 FDG accumulation that constitutes an abnormal level referring to blood parameters.

METHODS

Records of 65 patients, 32 with benign diseases and 33 with malignancies without metastasis in bone and liver until a half year after the PET examination, were analyzed retrospectively. Regions of interest were placed on the liver and the lower thoracic and lumbar vertebrae to measure the standardized uptake value (SUV), and vertebral SUVs were averaged as the BM SUV(mean). The BM SUV(mean) was divided by the liver SUV to calculate the BM/liver ratio. The relationships among the BM SUV(mean), or BM/liver ratio, and blood parameters and age were tested using multiple regression analysis.

RESULTS

In both patients with and without malignancy, a multiple regression model using the BM/liver ratio showed a higher coefficient of determination value than that using the BM SUV(mean), indicating that the correction by the liver SUV reduced the interindividual variation in the BM SUV(mean). The BM/liver ratio was negatively correlated with age (beta = -0.41 and -0.43, respectively) and positively correlated with serum C-reactive protein (CRP) level (beta = 0.39 and 0.46, respectively) in both groups of patients. Every patient with benign disease who had a ratio greater than or equal to 1 had an increased CRP level.

CONCLUSIONS

The BM F-18 FDG uptake depends on the patient's age and serum CRP level, both with and without malignancy. A BM F-18 FDG uptake greater than or equal to that of the liver may indicate BM activation.

Rhabdomyosarcoma With Widespread Bone Marrow Infiltration

Alveolar rhabdomyosarcoma (RMS) accounts for 20% to 30% of childhood RMS and is associated with a prognosis worse than embryonal RMS. Disseminated RMS can present with extensive bone marrow involvement. Assessing the extent of the tumor is critical, because therapy and prognosis depend on the degree to which the mass has spread beyond the primary site. The value of F-18 FDG PET in patients with RMS has been reported in some series but none specifically involving bone marrow. Children have a highly cellular hematopoietic bone marrow and differentiation of a highly cellular marrow from neoplastic infiltration may be difficult. Various other conditions associated with diffuse FDG uptake in the bone marrow include marrow hyperplasia resulting from hemolytic/iron-deficiency/blood-loss anemia, after chemotherapy with granulocyte/macrophage colony-stimulating factor and recombinant erythropoietin treatment, leukemia, non-Hodgkin lymphoma, and myelodysplasia. It is therefore important to consider the above differential diagnoses in mind when evaluating cases of unexpected marrow uptake in F-18 FDG PET studies. We report here a case of RMS with diffuse bone marrow involvement detected on F-18 FDG PET wherein FDG PET was useful in determining the true extent (primary and metastases) of RMS before definitive therapy and the valuable adjunct role it has with structural imaging in management.

Intercostal Muscle Contraction or Rib Bone Marrow Activity?

Diffuse and uniform FDG uptake in the ribs and the intercostal muscles might appear similar on FDG-PET images and a reliable differentiation between the two is important for accurately identifying the underlying process. The former usually suggests excessive contraction of intercostal muscles mostly due to chronic obstructive pulmonary disease, whereas the latter signifies either bone marrow stimulation or involvement by a pathologic process. At times, images may appear confusing and may be misinterpreted. However, in both clinical settings, there are additional ancillary signs, which are helpful in making a correct diagnosis. We herein present 2 case vignettes from each category in which other ancillary signs helped to distinguish FDG rib uptake from intercostal muscle uptake.