The usefulness of (18)F-FDG PET/CT for assessing methotrexate-associated lymphoproliferative disorder (MTX-LPD)

Magnetic resonance imaging of methotrexate-related lymphoproliferative disorder with a chief complaint of oral symptoms

OBJECTIVES

To determine the magnetic resonance imaging (MRI) features of methotrexate-related lymphoproliferative disorder (MTX-LPD) in the oral cavity of a patient with a chief complaint of oral symptoms.

METHODS

We included six patients who visited our hospital between November 2014 and November 2019, histopathologically diagnosed with MTX-LPD. All images were examined using 3 T MRI and reviewed by two radiologists.

RESULTS

Masses were detected in five cases; all masses demonstrated signal hypointensity and homogeneous signal hyperintensity on T1- and T2-weighted images with fat suppression. Homogeneous enhancement with fat suppression was evident on post-contrast T1-weighted imaging. We performed dynamic contrast-enhanced MRI in three cases and observed early enhancement with a low washout ratio pattern in all cases. Four patients underwent diffusion-weighted MRI and revealed low mean apparent diffusion coefficient (ADC) of 0.57 (range 0.5-0.65) × 10^-3 mm²/s.

CONCLUSIONS

We reported on the imaging characteristics of six rare cases of MTX-LPD in the oral cavity. Homogeneous hyperintensity on fat-suppressed T2-weighted images and low ADC values are possible features of MTX-LPD. Moreover, MTX-LPD can be differentiated from other carcinomas in the oral cavity.

FDG-PET/CT imaging parameters for predicting spontaneous regression of methotrexate-associated lymphoproliferative disorder in patients with rheumatoid arthritis

In this study, we investigated the usefulness of FDG-PET/CT for predicting spontaneous regression in methotrexate-associated lymphoproliferative disorder (MTX-LPD). Twenty patients with rheumatoid arthritis who were diagnosed with MTX-LPD were enrolled in the study. These patients were divided into those who showed spontaneous regression (SR group: ten patients) and those who received chemotherapy after discontinuation of MTX (CTx group: ten patients). Between-group differences in potential biomarkers were compared, including clinical markers at the onset of LPD [serum LDH and interleukin 2 receptor (sIL-2R)], change in absolute number of peripheral lymphocytes (ΔALC) over follow-up, and the FDG-PET/CT-derived parameters of maximum standardized uptake value (SUVmax), mean SUV (SUVmean), peak SUV (SUVpeak), sum of the metabolic tumor volume (MTVsum), and sum of total lesion glycolysis (TLGsum). The levels of sIL-2R, MTVsum, and TLGsum were significantly lower in the SR group than in the CTx group. In addition, ΔALC was higher in the SR group. In conclusion, MTV and TLG values measured by FDG-PET/CT may be suitable for use as predictors of SR in patients with MTX-LPD.

Weight loss as primary indication for FDG-PET/CT

PURPOSE

Some consider fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) clinically useful in patients presenting with nonspecific symptoms of malignancy, weight loss most commonly encountered. However, the appropriateness of such FDG-PET/CT studies remains to be clarified. This study evaluated the clinical value of FDG-PET/CT in patients referred primarily for weight loss.

METHODS

From 2010 to 2017 in one academic center, 252 subjects underwent 254 FDG-PET/CT studies for weight loss as primary indication and retrospectively studied. Eighteen subjects were excluded due to ongoing active malignancy, weight loss not ultimately being the main indication for the FDG-PET/CT, technically inadequate FDG-PET/CT and insufficient follow-up. The FDG-PET/CT scans were considered clinically beneficial when true positive for the cause of weight loss that other investigations missed or would have missed, clinically neutral when true negative and clinically detrimental when false positive leading to additional investigations or false negative.

RESULTS

Ultimately 234 unique subjects (236 FDG-PET/CT studies) were included. The average subject weight loss prior to the PET was 12 kg and average follow-up time post FDG-PET/CT scan was 3.4 years. The FDG-PET/CT scans were true positive in 24 studies (10%) with 8 studies (3%) clinically beneficial; false positive in 38 studies (16%) of which 26 led to 35 additional procedures and false negative in 13 studies (6%). In total, 39 (17%) FDG-PET/CT studies were clinically detrimental. The other 149 (63%) studies were true negative, clinically neutral.

CONCLUSION

FDG-PET/CT appears to have limited value in assessing subjects with weight loss as the leading clinical indication, proving to be five times more often detrimental than beneficial.

Clinical features and treatment strategies for post-transplant and iatrogenic immunodeficiency-associated lymphoproliferative disorders

A specific category termed immunodeficiency-associated lymphoproliferative disorders (LPD) exists in the 2016 revised WHO classification concerning lymphoid neoplasms. This category is defined by etiology and includes LPD developing in association with organ transplantation or immunosuppressive/immunomodulatory agents including methotrexate. The functional mechanism is chiefly explained by the autonomous proliferation of Epstein-Barr virus (EBV)-infected lymphocytes induced by host-immune suppression. This category ranges from reactive lymphocyte hyperplasia to monomorphic lymphoma. Its clinical behavior varies depending on host immunity and pathological features; pathological confirmation by biopsy is thus important for deciding treatment strategies. Owing to the spontaneous regression observed in some patients, uniform chemotherapy is not recommended. The main initial treatment options include the reduction in immunosuppressive drugs, immunotherapy with the anti-CD20 antibody rituximab, chemotherapy, or a combination of these. Other novel treatments such as adoptive immunotherapy with EBV-specific cytotoxic T cells, could be an alternative for relapsed/refractory diseases in clinical trials.

Methotrexate-associated Lymphoproliferative Disorder in the Liver Resembling Hepatocellular Carcinoma Treated with Transarterial Chemoembolization

Methotrexate-related lymphoproliferative disorder (MTX-LPD) is known to be a side effect of MTX, but its involvement in the liver has been rarely reported. We herein report a 70-year-old woman with autoimmune hepatitis and rheumatoid arthritis who developed multiple liver tumors. We initially considered that she had developed rapid-growing hepatocellular carcinoma (HCC) in the cirrhotic liver based on imaging tests. A tumor biopsy and transcatheter arterial chemoembolization were thus performed. The tumors were then diagnosed as diffuse large B-cell lymphoma pathologically and considered to be MTX-LPD. This case indicates that MTX-LPD should be considered even in cirrhotic patients with liver tumors resembling HCC.

Three different CT and FGD PET/CT findings of pulmonary involvement in methotrexate-associated lymphoproliferative disease

Lymphoproliferative disease (LPD) is one of the complications of methotrexate (MTX) therapy. In MTX-associated LPD (MTX-LPD), LPD lesions limited to the lungs are rare and show various types of opacity. A 75-year-old woman with rheumatoid arthritis (RA) presented with myalgia. She had been taking MTX for 11 years. Chest computed tomography (CT) scans showed a nodule in the left lower lobe that had grown significantly and a new nodule in the right lower lobe. 18F-fluorodeoxyglucose (FDG)/positron emission tomography (PET)/CT revealed significant FDG uptake in these nodules. Transbronchial biopsy specimen showed diffusely distributed CD20-positive lymphoid cells, and we made a diagnosis of MTX-LPD. All lung lesions disappeared within months after the immediate discontinuation of MTX. We also had two other patients with MTX-LPD lung lesions that had high FDG uptake. FDG PET/CT might be a useful diagnostic tool as it may reflect disease progression and help identify separate lesions.

Methotrexate-associated lymphoproliferative disorder with hypopituitarism and central diabetes insipidus

SUMMARY

Patients treated with immunosuppressive drugs, especially methotrexate (MTX), rarely develop lymphoproliferative disorders (LPDs), known as MTX-related LPD (MTX-LPD). The primary site of MTX-LPD is often extranodal. This is the first reported case of MTX-LPD in the pituitary. A 65-year-old woman was admitted to our hospital with symptoms of oculomotor nerve palsy and multiple subcutaneous nodules. She had been treated with MTX for 11 years for rheumatoid arthritis. Computed tomography showed multiple masses in the orbit, sinuses, lung fields, anterior mediastinum, kidney, and subcutaneous tissue. Brain magnetic resonance imaging revealed a sellar mass. She was diagnosed with hypopituitarism and central diabetes insipidus based on endocrine examination. Although pituitary biopsy could not be performed, we concluded that the pituitary lesion was from MTX-LPD, similar to the lesions in the sinuses, anterior mediastinum, and subcutaneous tissue, which showed polymorphic LPD on biopsy. MTX was discontinued, and methylprednisolone was administered to improve the neurologic symptoms. After several weeks, there was marked improvement of all lesions, including the pituitary lesion, but the pituitary function did not improve. When pituitary lesions are caused by MTX-LPD, the possibility of anterior hypopituitarism and central diabetes insipidus needs to be considered. Further studies are needed to investigate the effectiveness of early diagnosis and treatment of MTX-LPD in restoring pituitary dysfunction.

LEARNING POINTS

Pituitary lesions from MTX-LPD may cause hypopituitarism and central diabetes insipidus. Pituitary metastasis of malignant lymphoma and primary pituitary lymphoma, which have the same tissue types with MTX-LPD, have poor prognosis, but the lesions of MTX-LPD can regress only after MTX discontinuation. In cases of pituitary lesions alone, a diagnosis of MTX-LPD may be difficult, unless pituitary biopsy is performed. This possibility should be considered in patients treated with immunosuppressive drugs. Pituitary hypofunction and diabetes insipidus may persist, even after regression of the lesions on imaging due to MTX discontinuation.

Cardiac Methotrexate-Induced Lymphoproliferative Disorder

Methotrexate has been reported as an immunosuppressive agent associated with lymphoproliferative disorders. This report describes the case of a cardiac methotrexate-induced lymphoproliferative disorder that could be differentiated from a sinus of Valsalva aneurysm rupture by cardiac magnetic resonance imaging and fluorine-18 (¹⁸F)-fluorodeoxyglucose positron emission tomography combined with computed tomography. The definitive diagnosis was made by a tissue biopsy that was concomitantly performed with sinus of Valsalva aneurysm repair. Significant regression was seen in response to methotrexate withdrawal. To the best of our knowledge, this is the first case of a cardiac methotrexate-induced lymphoproliferative disorder.

Treatment of advanced stage methotrexate-associated lymphoproliferative disorders (MTX-LPDs) with methotrexate discontinuation

We present two cases of patient's with long-standing autoimmune diseases being treated with immunosuppressants that developed aggressive lymphoproliferative disorders. Immunosuppressants have a well-known association with disorders. Sustained regression of these lymphoproliferative disorders occurred with simple discontinuation of these immunosuppressive agents.

18 F-FDG PET-CT in a patient with methotrexate-associated lymphoproliferative disorder

¹⁸F‐FDG PET‐CT clearly demonstrated the disease activity of MTX‐LPD.

Pathogenesis and FDG-PET/CT findings of Epstein-Barr virus-related lymphoid neoplasms

Epstein-Barr virus (EBV) is one of the most common viruses, infecting more than 90% of the adult population worldwide. EBV genome is detected in some lymphoid neoplasms. Not only their histopathological subtypes, but also their backgrounds and their clinical courses are variable. A number of B-cell lymphoproliferative disorders associated with the immunocompromised state are related to EBV infection. The incidences of these disorders have been increasing along with generalization of organ transplantations and use of immunosuppressive treatments. Furthermore, some EBV-positive lymphoma can also occur in immunocompetent patients. While evaluating patients with generalized lymphadenopathy of unknown cause by positron emission tomography/computed tomography with 2-deoxy-2-[¹⁸F]fluoro-D-glucose (FDG-PET/CT), the possibility of lymphoid neoplasms should be considered in some patients, and a careful review of the background and previous history of the patients is necessary. In this review article, we describe the pathogenesis of EBV-related lymphoid neoplasms and then present FDG-PET/CT images of representative diseases. In addition, we also present a review of other EBV-related diseases, such as infectious mononucleosis and nasopharyngeal carcinoma.

Prognostic value of whole-body SUVmax of nodal and extra-nodal lesions detected by 18F-FDG PET/CT in extra-nodal NK/T-cell lymphoma

We analyzed data from 54 newly-diagnosed persons with extra-nodal natural killer/T-cell (NK/T) lymphoma, who had a pretreatment 18F-FDG PET/CT study, to determine whether the sum of SUVmax of all the nodal and extra-nodal lesions predicted progression-free survival (PFS) and/or overall survival (OS). Three models (WB1SUVmax, WB2SUVmax, WB3SUVmax) based on the basis of the sum of SUVmax of the whole-body SUVmax of 11 nodal and 10 extra-nodal lesions were tested. The discrimination value of these models was evaluated using time-dependent receiver-operator characteristic (ROC) curves and corresponding areas under the curve (AUC) in training and validation cohorts. Findings were validated in an independent cohort of 15 subjects. ROC curve analysis showed the optimal cut-off values for WB1SUVmax, WB2SUVmax and WB3SUVmax were 15.8 (sensitivity 92%, specificity 67%, AUC 0.811; P<0.001), 12.7 (sensitivity 96%; specificity 57%; AUC 0.785; P<0.001) and 15.8 (sensitivity 88%; specificity 70%; AUC 0.793; P<0.001). Multivariate analyses indicated WB3SUVmax was independently associated with PFS (hazard ratio [HR]=3.67, 95% confidence interval [95% CI]=1.19, 11.29; P=0.023) and OS (HR= 4.51 [1.02, 19.91]; P=0.047). WB3SUVmax calculated based of the sum of the SUVmax of 3 nodal and 10 extra-nodal lesions was significantly associated with PFS and OS.