Case 107: Lymphoma of the Mesentery

CT features associated with underlying malignancy in patients with diagnosed mesenteric panniculitis: Mesenteric panniculitis: CT features associated with underlying malignancy

PURPOSE

The purpose of this study was to identify abdominal computed tomography (CT) features associated with underlying malignancy in patients with mesenteric panniculitis (MP).

MATERIALS AND METHODS

This single-institution retrospective longitudinal cohort study included patients with MP and a minimum 1-year abdominopelvic CT follow-up or 2-year clinical follow-up after initial abdominopelvic CT examination. Two radiologists, blinded to patients' medical records, conjointly reviewed CT-based features of MP. Electronic medical records were reviewed for newly diagnosed malignancies with the following specific details: type (lymphoproliferative disease or solid malignancy), location (possible mesenteric drainage or distant), stage, time to diagnosis. An expert panel of three radiologists and one hemato-oncologist, who were blinded to the initial CT-based MP features, assessed the probability of association between MP and malignancy based on the malignancy characteristics.

RESULTS

From 2006 to 2016, 444 patients with MP were included. There were 272 men and 172 women, with a median age of 64 years (age range: 25-89); the median overall follow-up was 36 months (IQR: 22, 60; range: 12-170). A total of 34 (8%) patients had a diagnosis of a new malignancy; 5 (1%) were considered possibly related to the MP, all being low-grade B-cell non-Hodgkin lymphomas. CT features associated with the presence of an underlying malignancy were the presence of an MP soft-tissue nodule with a short axis >10 mm (P < 0.0001) or lymphadenopathy in another abdominopelvic region (P < 0.0001). Associating these two features resulted in high diagnostic performance (sensitivity 100%; [95% CI: 57-100]; specificity 99% [95% CI: 98-100]). All related malignancies were identified.

CONCLUSION

Further workup to rule out an underlying malignancy is only necessary in the presence of an MP soft-tissue nodule >10 mm or associated abdominopelvic lymphadenopathy.

Association between mesenteric panniculitis and non-neoplastic disorders

PURPOSE

To assess the relationship between MP and coexisting non-neoplastic disorders.

METHODS

Consecutive abdominal computed tomography (CT) scans of 4674 patients were evaluated retrospectively for CT features of MP between January 2017 and January 2018. Clinical findings of patients were analyzed. Four control patients were selected from our cohort for each MP patient such that they matched for age, gender and CT protocol. Statistical analysis was performed using a t, Mann-Whitney U, χ², or Fisher's test.

RESULTS

976 patients were excluded from the study due to the exclusion criteria and finally, 102/3698 patients were diagnosed with MP (mean age = 57.2 ± 12.5 years, 52% male). On CT, a hyperattenuated fatty mass (120/120), subcentimeter lymph nodes (117/120), congregation of mesenteric vessels (82/120) within the mass, a fat halo sign (28/120) and a pseudocapsule (88/120) were seen at the mesentery.The intra-observer agreement was almost perfect for the fatty mass and lymph nodes and moderate or substantial for other CT features (p < 0.001). The most prominent disorders were metabolic syndrome (MetS) and urogenital diseases in MP (45%, 37%, respectively) and control groups (31%, 26%, respectively). Between groups, no significant differences were found in the history of abdominal surgery, gastrointestinal and autoimmune diseases (p-value range 0.064-0.663); however, significant differences were found in the rates of vascular, urogenital diseases and MetS (p-value range 0.012-0.036).

CONCLUSION

MetS and urolithiasis were significantly more common in patients with MP than in those without MP. Therefore, there may be a clinically relevant association between these disorders. MetS may be a risk factor for MP and urolithiasis, and treatment of metabolic disorders should be undertaken to prevent these diseases.

Unravelling the Mysteries of the Mesentery

The mesentery and its folds tether the small bowel loops to the posterior abdominal wall. It transmits nerves, vessels, and lymph ensconced in a fatty sponge layer wrapped in a thin glistening peritoneum, from and to the small bowel. Not only does this flexible dynamic fatty apron house various localized primary benign and malignant lesions, it is often involved in and gives an indication of generalized or systemic diseases in the body. An understanding of the anatomy, components, and function of the mesentery helps to classify mesenteric abnormalities. This further allows for characterizing radiological patterns and appearances specific to certain disease entities. Recent reviews of mesenteric anatomy have kindled new interest in its function and clinical applications, heralding the possibility of revision of its role in diseases of the abdomen.

De-misty-fying the mesentery: an algorithmic approach to neoplastic and non-neoplastic mesenteric abnormalities

Mesenteric abnormalities are often incidentally discovered on cross-sectional imaging performed during daily clinical practice. Findings can range from the vague "misty mesentery" to solid masses, and the possible etiologic causes encompass a wide spectrum of underlying pathologies including infectious, inflammatory, and neoplastic processes. Unfortunately, the clinical and imaging findings are often non-specific and may overlap. This article discusses the various diseases that result in mesenteric abnormalities. It provides a framework to non-invasively differentiate these entities, when possible.

Sonography of peritoneal lymphomatosis: some new and different findings

OBJECTIVE

The purpose of this study was to assess the sonographic features of lymphoma with peritoneal, omental, and mesenteric involvement.

MATERIALS AND METHODS

All records of peritoneal biopsies under the guidance of ultrasound in our institutional database were retrospectively reviewed to find out cases with peritoneal, omental, and mesenteric lymphoma involvement. Sonographic studies of these patients were evaluated for the presence of peritoneal involvement, ascites, omental mass, organomegaly, retroperitoneal lymphadenopathy, and other associated findings.

RESULTS

Six cases of omental lymphoma and 3 cases of mesenteric lymphoma were included in the study. All the cases were diffuse large B-cell non-Hodgkin lymphomas. Under high-frequency insonation, the omentum became markedly irregularly thickened when involved by lymphoma, and in 4 cases, "fish scale" appearance was observed, and the fish scale was proved to be normal omental tissue by pathology. Hypoechoic mass or "sandwich" appearance of thickened mesenteric tissue could be observed in mesenteric lymphoma. The amount of ascites in omental lymphoma was much more than that in mesenteric lymphoma, and intensive echogenic particulate was found in ascites in 2 cases of omental lymphoma. Retroperitoneal lymphadenectasis was seen in only 3 cases, and the most common location was para-aortic.

CONCLUSIONS

The fish scale sign in the omentum and the sandwich sign of the mesentery might indicate the possibility of peritoneal lymphoma, and ultrasound seems to be the ideal imaging modality to show the thickened omentum and mesentery mass when lymphoma involves peritoneum.

Mesentery lymphoma in a patient with Crohn's disease: An extremely rare entity

INTRODUCTION

Lymphoma is a rare complication of long-standing Crohn's disease. We report a rare case of a diffuse, B-cell non-Hodgkin's lymphoma of the mesentery in a patient receiving treatment for Crohn's disease.

PRESENTATION OF CASE

A 52 year-old patient presented with abdominal pain, anorexia and postprandial fullness. Abdominal examination revealed a firm mass, extending from the epigastrium to the right iliac fossa. CT scan showed a large intra-abdominal mass with air-fluid levels within, and soft tissue density along its walls, surrounded by distended bowel loops. The patient was scheduled for surgery due to clinical assumption of an intra-abdominal abscess. At laparotomy an ill-defined, lobulated mass with cystic areas was noted rising from the mesentery. Frozen section biopsy of the cystic mass revealed a non-Hodgkin follicle center B-cell lymphoma of the mesentery.

DISCUSSION

To the best of our knowledge, this is an extremely rare case of lymphoma development in the mesentery, in a patient receiving treatment for Crohn's disease. Although the development of abdominal lymphomas can be justified as a possible consequence of the chronic immune-modulating therapy, their location can lead to diagnostic pitfalls.

CONCLUSION

Although mesentery has scarcely been presented as a potential site of occurrence of abdominal lymphomas in the process of treatment of inflammatory bowel diseases, this rare entity should be considered in the differential diagnosis of intra-abdominal lymphomas in patients with inflammatory bowel disease. In cases where imaging techniques do not provide definitive answers, surgical intervention can safely pose the accurate diagnosis.

Diffuse large B cell lymphoma of the mesentery: an unusual presentation and review of the literature

INTRODUCTION

Diffuse large B cell lymphoma is the most commonly diagnosed non-Hodgkin's lymphoma, whereas lymphoma is the most common cause of mesenteric masses. We herein present a very rare case of a young male patient with a giant diffuse large B cell lymphoma of the mesentery that was incidentally diagnosed during his admission for a road traffic accident.

MATERIALS AND METHODS

At laparotomy, a huge tumor measuring 18 x 14 x 10 cm was found originating from the jejunal mesentery. Despite the giant size of the tumor, the patient was completely asymptomatic. After complete surgical recection with clear margins, he recieved six cycles of CHOP chemotherapy in the pre-rituximab era.

RESULTS AND DISCUSSION

He remained disease-free 2 years after surgery, but unfortunately, he relapsed with disseminated disease and died 6 months later. Mesenteric lymphomas may remain asymptomatic until they reach a large size. The presence of a bulky mesenteric mass is a poor prognostic indicator.

CONCLUSION

Although chemotherapy is the treatment of choice for diffuse large B cell lymphoma, in some cases radical surgery has a role in establishing a definitive diagnosis.

Nonvascular mesenteric disease: utility of multidetector CT with 3D volume rendering

Creation of isotropic volumes with submillimeter multidetector computed tomography (CT) has expanded interpretative practice to routinely include two-dimensional (2D) and three-dimensional (3D) postprocessing techniques. Currently, 2D multiplanar reformatting, maximum intensity projection, and 3D volume rendering are available on most workstations. Only volume rendering yields a 3D display that depicts all tissue types from any orientation. Utility is not limited to vascular applications, as 3D volume rendering can be used to evaluate neoplastic, infectious, and inflammatory processes that affect the small-bowel mesentery. Specifically, interactive interpretation of multidetector CT data sets with volume rendering can help characterize nonvascular mesenteric disease, elucidate its extent through more comprehensive display, and facilitate the identification of complications.