Differentiation of Lymphoma Presenting as Retroperitoneal Mass and Retroperitoneal Fibrosis

Abstract

Background:Retroperitoneal fibrosis (RPF) and lymphoma presenting as retroperitoneal mass may closely resemble each other and misdiagnosis may occur. This study investigated the differential imaging features of RPF and lymphoma which presented as a retroperitoneal soft tissue using multidetector-row computed tomography (MDCT).Methods:The 42 consecutive patients were included in this retrospective review, including 19 RPF patients (45.2%; including 13 males and 6 females; mean age: 56.7 ± 6.2 years) and 23 patients with lymphoma (54.8%; including 14 males and 9 females; mean age: 57.4 ± 12.3 years). An array of qualitative computed tomography (CT) features of lesions in 42 consecutive patients with newly diagnosed untreated RPF and lymphoma were retrospectively analyzed. The quantitative size of the lesion at the para-aortic region and attenuation in the precontrast, arterial, and portal phases were calculated in regions of interest and compared between the patients with newly diagnosed untreated RPF and with lymphoma. Receiver operating characteristic curve analysis was used to assess the potential diagnostic value of each quantitative parameter. Inter-reader concordance was also calculated.Results:Mean ages between patients with RPF and lymphoma were not significantly different (56.7 ± 6.2 years vs. 57.4 ± 12.3 years P = 0.595). Compared to those in patients with lymphoma, homogeneous enhancement (65.2% vs. 94.7%, P = 0.027) and pelvic extension (52.2% vs. 89.5%, P = 0.017) were significantly more common while the involvement of additional nodes (78.3% vs. 5.3%, P < 0.001), suprarenal extension (60.9% vs. 15.8%, P = 0.004), and aortic displacement (43.5% vs. 5.3%, P = 0.006) were significantly less common in patients with RPF. Lesion size at the para-aorta was significantly greater in patients with lymphoma, compared with RPF patients (3.9 ± 1.2 cm vs. 1.8 ± 0.6 cm; P < 0.001). The attenuation values in three phases were not significantly different between patients with RPF and lymphoma. Inter-reader concordance for subjective features ranged from very good to excellent (range: 85.7–100.0%).Conclusions:This study showed that MDCT can help differentiate between untreated RPF and lymphoma on the basis of qualitative CT features and lesion sizes. Differentiating RPF from lymphoma on the basis of attenuation values in the precontrast, arterial, and portal phases was difficult to accomplish.

Validation of the diagnostic criteria for IgG4-related kidney disease (IgG4-RKD) 2011, and proposal of a new 2020 version

“…However, it should always be borne in mind that such imaging or clinical features might be evident in mimickers. In particular, retroperitoneal fibrosis as an imaging feature has been demonstrated in ANCA-associated vasculitis or malignant lymphoma [ 9 , 15 , 16 ]. In fact, the present cohort included one patient with MPA who showed imaging features of retroperitoneal fibrosis and IgG4-positive cell-rich TIN, although the level of serum IgG4 was not evaluated.…”

Renal Lymphoma Mimicking a Retroperitoneal Hematoma

“…The attenuation tends to be more homogeneous. Lymphoma may have areas of necrosis, with greater lesions and associated lymph nodes [ 10 ].…”

Retroperitoneal Fibrosis and its Differential Diagnoses: The Role of Radiological Imaging

“…B. Cristian et al postulieren, dass bildmorphologische Verfahren in ihrer Genauigkeit nicht ausreichen, eine maligne Genese der RPF auszuschließen [6]. Andere Autoren berichten Gegensätzliches und präsentieren signifikante Zusammenhänge zwischen bildmorphologischen Kriterien (Ausdehnung oberhalb der Nierenstilgefäße, retroperitoneale Ausbreitung mit Abhebung der Bauchaorta, zusätzlicher Nachweis vergrößerter Lymphknoten) und funktionellen Parametern (sehr hohe Tracer-Anreicherung bei atypischer Verteilung in der FDG-PET/CT) als Kriterien für eine maligne Genese der RPF [3,7,8]. Es bleibt also unklar, ob die histopathologische Sicherung in jedem Fall nötig ist; bei atypischer Lokalisation, klinischen oder diagnostischen Hinweisen auf eine maligne Genese und/oder bei fehlendem Ansprechen der Fibrose auf eine medikamentöse Therapie sollte die Gewinnung einer Histologie jedoch dringend angestrebt werden.…”

“…An dieser Stelle verweisen wir insbesondere auf die Arbeit von Zhang et al, welche signifikante CT-morphologische Unterschiede, wie Ausdehnung oberhalb des Nierengefäßstiels, retroaortale Ausbreitung und pathologisch vergrößerte Lymphknoten, beschrieben, was z. B. die Differenzialdiagnose des Lymphoms wahrscheinlich werden lässt [7]. Kriterien, die für eine RPF bzw.…”