Myeloid Sarcoma Presenting as an Anterior Mediastinal Mass Invading the Pericardium: Serial Imaging With F-18 FDG PET/CT

18 F-FDG PET/CT Imaging of Isolated Myeloid Sarcoma in the Right Humerus

ABSTRACT

Myeloid sarcoma is a neoplastic mass formed by the infiltration of primitive or immature myeloid cells into organs and tissues outside the bone marrow. It may occur before, at the same time, or manifest as the recurrence of acute myeloid leukemia, myelodysplastic syndromes, and chronic myeloproliferative syndromes. It may involve any organ or tissue, including skin, soft tissue, lymph nodes, and gastrointestinal tract and bone. Isolated humerus involvement is extremely rare. Herein, we present the FDG PET/CT findings of a rare case of isolate myeloid sarcoma in the right humerus, which showed only increased bone density with moderate FDG uptake.

18 F-FDG PET/CT Findings of Myeloid Sarcoma Involving the Left Ventricle and Kidney in a Pediatric Patient

ABSTRACT

A 1-year-old girl presented with vomiting for 1 week. Abdominal ultrasound revealed a mass with increased blood flow in the left lower abdomen. A malignancy was suspected. 18 F-FDG PET/CT showed multiple lesions in the left ventricular wall, the kidney, and the left lower abdomen. Biopsy of the left abdominal mass confirmed the diagnosis of myeloid sarcoma associated with acute myeloid leukemia. After 4 cycles of chemotherapy, follow-up PET/CT was performed for evaluating the therapy response, which showed complete resolution.

18F-FDG PET/CT Helps Differentiate Peripheral Nerve Myeloid Sarcoma From a Presumed Benign Nerve Sheath Tumor

A 21-year-old man with NF1 (neurofibromatosis type 1) mutation and in remission from acute myeloid leukemia presented with a painless mass in the left upper limb. MRI showed a soft-tissue mass involving the ulnar nerve presumed to be a nerve sheath tumor. F-FDG PET/CT was performed demonstrating high FDG avidity in the mass, prompting a biopsy. Histopathology and immunohistochemistry of the biopsy sample demonstrated myeloid sarcoma of the ulnar nerve. This case highlights the role of F-FDG PET/CT in raising the suspicion of malignancy in otherwise presumably benign lesions of the nerve.

The prevalence of extramedullary acute myeloid leukemia detected by 18FDG-PET/CT: final results from the prospective PETAML trial

Extramedullary (EM) disease in patients with acute myeloid leukemia (AML) is a known phenomenon. Since the prevalence of EM AML has so far only been clinically determined on examination, we performed a prospective study in patients with AML. The aim of the study was to determine the prevalence of metabolically active EM AML using total body ¹⁸Fluorodesoxy-glucose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) imaging at diagnosis prior to initiation of therapy. In order to define the dynamics of EM AML throughout treatment, PET-positive patients underwent a second ¹⁸FDG-PET/CT imaging series during follow up by the time of remission assessment. A total of 93 patients with AML underwent ¹⁸FDG-PET/CT scans at diagnosis. The prevalence of PET-positive EM AML was 19% with a total of 65 EM AML manifestations and a median number of two EM manifestations per patient (range, 1-12), with a median maximum standardized uptake value of 6.1 (range, 2-51.4). When adding those three patients with histologically confirmed EM AML who were ¹⁸FDG-PET/CT negative in the ¹⁸FDG-PET/CT at diagnosis, the combined prevalence for EM AML was 22%, resulting in 77% sensitivity and 97% specificity. Importantly, 60% (6 of 10) patients with histologically confirmed EM AML still had active EM disease in their follow up ¹⁸FDG-PET/CT. ¹⁸FDG-PET/CT reveals a high prevalence of metabolically active EM disease in AML patients. Metabolic activity in EM AML may persist even beyond the time point of hematologic remission, a finding that merits further prospective investigation to explore its prognostic relevance. (Trial registered at clinicaltrials.gov identifier: 01278069.)

Long-Term Remission following Autologous Hematopoietic Cell Transplantation in a Patient with Multiple Nonleukemic Myeloid Sarcoma and a Review of the Literature

Multiple nonleukemic myeloid sarcoma (MS) is a rare form of MS that is developed in multiple anatomic sites other than bone marrow at diagnosis, without a preceding myeloid neoplasm. The prevalence, prognosis, and optimal management of multiple nonleukemic MS have not been addressed. The role of allogenic or autologous hematopoietic cell transplantation (HCT) for nonleukemic MS is also less well defined. We present a case of MS characterized by systemic lymphadenopathies and multiple effusions, which presumably had a very poor prognosis. The patient was treated with acute myeloid leukemia-type induction chemotherapy and autologous peripheral blood stem cell transplantation, and, unexpectedly, she has remained disease free for more than 6 years. We also reviewed the literature on this rare disease, and found that multiple nonleukemic MS was associated with younger age and a worse prognosis when compared with the overall nonleukemic MS population. We suggest that autologous HCT represents a valid option for young patients with chemosensitive disease and should be performed at the status of minimal residual disease-negative complete remission.

Cardiac Myeloid Sarcoma: Review of Literature

Granulocytic Sarcomas (GS) also called as Myeloid Sarcomas (MS) or chloromas are the representatives of extramedullary infiltrates of immature myeloid cells including myeloblasts, promyelocytes and myelocytes. Primary cardiac malignancies per se are rare and infiltration of cardiac muscles by secondary malignant cells is also an uncommon finding. Out of these cardiac tumors, contribution of Cardiac Myeloid Sarcoma (CMS) is even more smaller thereby limiting our knowledge about this rare entity. Because of its very lower incidence, an exact guideline for diagnosis and management is still missing and usually haematologists around the world are treating CMS based on their clinical acumen. Aim of this review is to briefly discuss the presenting clinical feature, differential diagnosis, diagnostic workup and management based on published articles related to CMS till date.

FDG PET/CT Findings of Intracardiac Myeloid Sarcoma

Myeloid sarcoma is a rare entity, and cardiac involvement is even rarer. We presented here the FDG PET/CT findings of a 66-year-old man with a 3-month history of cough and progressive dyspnea. FDG PET/CT scan demonstrated nonuniform FDG uptake in the cardiac walls and pericardium. Biopsy of the heart revealed myeloid sarcoma. In addition, bone marrow biopsy demonstrated the acute myeloid leukemia.

18 FDG-PET/CT: 21st century approach to leukemic tumors in 124 cases

Extramedullary tumors remain an obstacle to curing more acute leukemia patients. Their incidence is unknown because the presence of occult tumors that contribute to relapse is not routinely sought as in other cancers. No standard approach exists for treating tumors at most sites, apparent clinical response is typically followed by further tumors, and achievement of lengthy remission is uncommon. Body scanning with (18) FDG PET/CT now provides a means to identify the extent of occult tumors that enables directed tumor eradication and a way to evaluate tumor response. To evaluate its potential benefits, analysis was undertaken of 124 published cases scanned after apparent tumors were diagnosed. Clinical and radiologic exams underestimated extent of disease in over half of 100 cases. Among 70 cases that reported scans after various treatments, 70% achieved negative scans. Half relapsed subsequently but disease-free survivals up to 6 years were documented. These reported cases add to our knowledge of extramedullary leukemia in showing that further tumors are more likely than marrow relapse, clinical and radiologic evaluation of response is inadequate, intensive chemotherapy alone generally does not prevent progression and is associated with significant mortality, and tumor-directed plus systemic therapies appears the most effective approach, particularly to AML tumors. This analysis suggests this technology could increase our ability to eradicate all foci of leukemia, and identify tumors responsible for refractory, residual, and relapsed disease.

Usefulness and pitfalls of F-18-FDG PET/CT for diagnosing extramedullary acute leukemia

PURPOSE

It is very important to identify whether there is extramedullary involvement in acute leukemia (AL), especially in those with recurrent disease. This retrospective study aimed to assess the role of (18)F-FDG PET/CT for diagnosing extramedullary AL.

MATERIALS AND METHODS

PET/CT examinations were performed in 9 patients with newly diagnosed AL, and 70 patients suspected to have recurrent AL. All the patients were diagnosed with AL by bone marrow biopsy. The diagnosis of extramedullary lesions was established according to the combination of pathology, physical examination, and imaging techniques including magnetic resonance imaging (MRI) and PET/CT, and/or cerebrospinal fluid (CSF) cytologic testing, and clinical follow-up.

RESULTS

Of the 79 patients, including 34 acute lymphocytic leukemia (ALL) and 45 acute myeloid leukemia (AML) cases, 30 patients were diagnosed with extramedullary AL. (18)F-FDG PET/CT demonstrated (18)F-FDG positive lesions in the extramedullary regions in 42 patients. Among them, 28 patients were diagnosed to have extramedullary AL and the other 14 were diagnosed with non-hematological malignancies (false positive disease). The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT in diagnosing extramedullary involvement of AL were 93.3% (28/30), 71.4% (35/49), and 79.7%, respectively. The (18)F-FDG uptake of lesions was not significantly different between extramedullary AL and false positive cases (SUVmax: 6.66 ± 2.65 vs. 5.85 ± 1.88, t=1.275, P=0.206). The FDG uptake of extramedullary AL between ALL and AML were also not significantly different (SUVmax: 7.01 ± 2.82 vs. 6.10 ± 2.29, t=1.332, P=0.188). The predominant locations of extramedullary AL were the spleen, soft tissue, lymph nodes, central nerve system, liver, testis, and kidney. A total of 48.2% (27/56) of extramedullary AL lesions presented as diffuse FDG uptake compared with 6.25% (1/16) in the false positive lesions (χ(2)=9.221, P=0.002).

CONCLUSION

(18)F-FDG PET/CT is a sensitive, but not specific imaging modality for diagnosing extramedullary AL. Diffuse (18)F-FDG uptake in extramedullary lesions may indicate leukemia involvement.

Intrathoracic extramedullary hematopoiesis presenting as tumor-simulating lesions of the mediastinum in α-thalassemia: A case report

Extramedullary hematopoiesis (EMH) is a rare disease, where hematological disorder drives extramedullary hematopoietic tumor formation in multiple regions of the body. The present study reports a case of EMH presenting as multiple tumor-like lesions of mediastinum in a 61-year-old male with α-thalassemia, which was subjected to a video-assisted thoracoscopic surgery tissue biopsy to differentiate it from other mediastinal tumors. To date, only three cases of EMH in patients with α-thalassemia have been described in the literature. Patients with EMH typically exhibit no hematological disorder preoperatively and therefore EMH is frequently misdiagnosed. In the present study, along with a literature review of the clinicopathological features of EMH, the diagnosis and treatment of this rare case was discussed, in order to differentiate diagnosis, and particularly to distinguish EHM from extramedullary myeloid sarcoma.

Appearance of recurrent cardiac myxofibrosarcoma on FDG PET/CT

Primary cardiac sarcomas are extremely rare tumors. In this case report, we presented the condition of a 37-year-old male patient diagnosed with myxofibrosarcoma after histopathologic evaluation of the left atrium mass excision. FDG PET/CT was performed and showed recurrent hypermetabolic lesions in the left atrial wall and right anterior mediastinal region.

18F-FDG PET/CT imaging in primary cardiac angiosarcoma: diagnosis and follow-up

A 40-year-old woman presented with recurrent chest tightness and shortness of breath for 10 days. The echocardiogram and MRI revealed a mass in the right atrium. FDG PET/CT was performed for further evaluation. The images demonstrated abnormally increased activity in the right atrial mass. The result of pathological examination after the surgical removal of the mass was consistent with angiosarcoma. Despite of receiving aggressive therapy including radiation, the patient had recurrent and metastatic malignancy 8 months later.

(18)F-FDG PET/CT in differentiating acute tuberculous from idiopathic pericarditis: preliminary study

PURPOSE

The aim of this study was to evaluate retrospectively the diagnostic capability of F-FDG PET/CT in differentiating acute tuberculous from idiopathic pericarditis.

METHODS

FDG PET/CT findings were reviewed in 15 patients with acute tuberculous (n = 5) or idiopathic pericarditis (n = 10). The maximal thickness and SUVmax of the pericardium and the number, size, and SUVmax of the mediastinal and supraclavicular lymph nodes with increased FDG uptake were measured.

RESULTS

All patients had small-to-large amount of pericardial effusion. The patients with acute tuberculous pericarditis (n = 5) showed diffuse (n = 3) or multifocal (n = 2) FDG uptake in the pericardia. The patients with acute idiopathic pericarditis (n = 10) showed diffuse (n = 6) or regional (n = 4) FDG uptake in the pericardia. The mean (SD) pericardial thickness and SUVmax of acute tuberculous pericarditis were significantly higher than those of acute idiopathic pericarditis (5.1 [1.0] vs 3.4 [0.9], P < 0.05; 13.5 [3.9] vs 3.0 [0.7], P < 0.05, respectively). A total of 69 mediastinal and supraclavicular lymph nodes with increased FDG uptake were observed in all 15 patients (44 in patients with acute tuberculous pericarditis and 25 in patients with acute idiopathic pericarditis). The mean (SD) SUVmax of mediastinal and supraclavicular lymph nodes of acute tuberculous pericarditis (5.3 [1.8]) was significantly higher than that of acute idiopathic pericarditis (2.8 [0.6], P < 0.05). There was no significant difference in the mean size of the mediastinal and supraclavicular lymph nodes between acute tuberculous and idiopathic pericarditis.

CONCLUSIONS

The degrees of FDG uptake in the pericardium and the mediastinal and supraclavicular lymph nodes are useful for differentiating acute tuberculous from idiopathic pericarditis. Familiarity with the FDG uptake patterns of acute tuberculous and idiopathic pericarditis may be helpful for successful (especially timely) diagnosis and treatment.

Extramedullary disease in patients with acute myeloid leukemia assessed by 18F-FDG PET

BACKGROUND

Prevalence of extramedullary disease (EMD) in acute myeloid leukemia (AML) at the time of diagnosis is unknown. Previous estimates range from 2.5% to 30.5% and are usually based on clinical examination. This may cause an under diagnosis of EMD as not all extramedullary manifestations are easily detectable. Few recent studies have used positron emission tomography (PET) scans for diagnosing EMD in patients AML.

METHOD

During a 9-month period, newly diagnosed patients with AML who were candidates for intensive chemotherapy were 18F-Fluoro-deoxy-glucose (FDG) PET-scanned prior to induction treatment. We compared the prevalence of EMD diagnosed by PET scans and by clinical examination. Subsequent PET scans following induction chemotherapy were performed for response evaluation of EMD.

RESULTS

Twenty-six patients were included in the study. 18-F-FDG PET scans revealed more than twice as many patients with EMD than found by clinical examination (65% vs. 31%). PET demonstrated 55 EMD lesions compared with 15 diagnosed by clinical examination. In general, the responses of EMD detected by PET scans were concordant with the bone marrow responses assessed by pathology examination.

CONCLUSION

18-F-FDG PET is a useful tool for diagnosing EMD in AML and for assessing treatment responses of EMD in AML.

Aleukemic granulocytic sarcoma presenting at multiple sites: ovary, breast and soft tissue

An 18 year old female presented with the history of pain in abdomen, breast engorgement, swelling over both legs and breathlessness for three month. On clinical examination diagnosis of fibroadenoma breast was made. Ultrasonography of abdomen showed bilateral ovarian mass. Bilateral salpingo-ophrectomy was done and specimen was sent for histological examination. Two lobulated solid masses of tissues the larger one measuring 13×8×5 cm and smaller one measuring 10×7×5 cm in size received. Microscopic examination showed monomorphic population of discohesive, hyperchromatic small round cells had high N:C ratio, coarse chromatin, conspicuous nucleoli and scant to moderate amount of basophilic cytoplasm, lying in sheets and separated by fibrous strands and diffusely infiltrating the ovarian stroma. Fine needle aspiration from breast lump and leg swelling showed predominant population of blast cells. Myeloperoxidase was strongly positive and diagnosis of granulocytic sarcoma was confirmed.

Myeloid Sarcoma and Acute Myelomonocytic Leukemia in an Adolescent with Tetrasomy 8: Staging with (18)F-FDG PET/CT

Tetrasomy 8 is a relatively rare chromosomal abnormality that has been reported in only 33 cases in hematologic disorders. It is known for its association with aggressive acute myeloid leukemia (AML) and myeloid sarcoma and is considered a very poor prognostic factor. Myeloid sarcoma is a rare hematologic malignancy characterized by tumor masses consisting of immature myeloid cells, presenting at an extramedullary site. We present a case of a 17-year-old boy referred for an (18)F-FDG PET/CT for the evaluation of pleural masses and spinal bone lesions seen on CT, after presenting with a 4 month history of chest pain. The PET/CT revealed extensive FDG-avid extramedullary disease in the soft tissues of the chest, abdomen, and pelvis, which were biopsy-proven to be myeloid sarcoma, as well as extensive intramedullary disease biopsy proven to be AML. This is the first report of the use of (18)F-FDG PET/CT to stage a subset of aggressive AML and myeloid sarcoma in a patient with an associated chromosomal abnormality (tetrasomy 8).

Extramedullary gastric relapse of acute lymphoblastic leukemia following allogeneic stem cell transplant: staging with F-18 FDG PET/CT

A 26-year-old man with a prior history of acute leukemia that was treated with a stem cell transplant (SCT) was referred for an F-18 FDG PET/CT to assess suspicious new gastric mucosal lesions. The lesions were FDG-avid and were histologically proven to be acute lymphoblastic leukemia (ALL). Extramedullary relapse of ALL after SCT is very rare, with only 60 cases reported in the literature, and the role of F-18 FDG PET/CT in monitoring for ALL relapse following SCT has not been previously investigated. This rare case report highlights the use of F-18 FDG PET/CT in staging gastric relapse of ALL following SCT.

Review of Physiologic and Pathophysiologic Sources of Fluorodeoxyglucose Uptake in the Chest Wall on PET

The chest wall can be defined as the osseous and soft tissue structures that form the outer framework of the thorax and move during breathing. Topics discussed in this article include physiologic uptake of fluorodeoxyglucose, benign diseases of the chest wall, and malignant tumors of the chest wall.