Mesenteric panniculitis is a chronic inflammation of the mesenteric adipose tissue, of uncertain clinical significance and with a possible link to malignancy. This study evaluated the clinical, radiological and prognostic characteristics of primary and secondary forms in an internal medicine cohort.
MethodsA retrospective cohort of adults with a radiological diagnosis of mesenteric panniculitis (2013–2024), analyzing demographic data, comorbidities, clinical presentation, radiological findings and clinical course. Cases were classified as primary or secondary when associated malignancy, autoimmune disease, or infection was present.
ResultsOne hundred eleven patients included (50% women; mean age 72.2±13.1 years). 61.3% were primary and 38.7% secondary. 31.5% were asymptomatic; abdominal pain was the most common symptom. Mesenteric thickening was the predominant radiological finding. During follow-up, 85.6% remained clinically stable. Overall mortality was 8.1%, slightly higher in secondary forms, mainly those associated with neoplasms, with no significant differences compared to primary cases.
ConclusionsMesenteric panniculitis mainly affected older adults, with a generally indolent course in primary forms, whilst secondary forms showed greater comorbidity.
La paniculitis mesentérica es una inflamación crónica del tejido adiposo mesentérico, de relevancia clínica incierta y posible vínculo con malignidad. El estudio evaluó las características clínicas, radiológicas y pronósticas de las formas primarias y secundarias en una cohorte de Medicina Interna.
MétodosCohorte retrospectiva de adultos con diagnóstico radiológico de paniculitis mesentérica (2013–2024), analizando datos demográficos, comorbilidades, clínica, hallazgos radiológicos y evolución. Los casos se clasificaron como primarios o secundarios cuando coexistía neoplasia, enfermedad autoimmune o infección.
Resultados111 pacientes incluidos (50% mujeres; edad media 72,2±13,1 años). El 61,3% fueron primarias y el 38,7% secundarias. El 31,5% estaban asintomáticos; el dolor abdominal fue el síntoma más frecuente. El engrosamiento mesentérico fue el hallazgo radiológico predominante. Durante el seguimiento, el 85,6% permaneció clínicamente estable. La mortalidad global fue del 8,1%, ligeramente mayor en las formas secundarias, principalmente las asociadas a neoplasias, sin diferencias significativas respecto a las primarias.
ConclusionesLa paniculitis mesentérica afectó principalmente a adultos mayores, con un curso generalmente indolente en las formas primarias, mientras que las secundarias mostraron mayor comorbilidad.
Mesenteric panniculitis (MP) is a rare chronic inflammatory disorder of mesenteric adipose tissue, typically involving the small bowel mesentery.1 It is increasingly detected as an incidental finding on abdominal computed tomography (CT).2 Its clinical relevance remains uncertain, particularly regarding associations with systemic diseases, malignancy, and the need for diagnostic evaluation and follow-up.1–4
Prevalence in CT-based series varies widely. Many patients are asymptomatic or present with nonspecific gastrointestinal symptoms such as abdominal pain, bloating, or weight loss, making causal attribution difficult.3–5,7 MP may occur as a primary idiopathic condition or as a secondary phenomenon associated with previous abdominal surgery or trauma, infections, autoimmune diseases, or malignancies.1,3,5,8,10 Although a possible association with cancer has been suggested, available evidence is heterogeneous and does not support a clear causal relationship.4,5,9,10
Contrast-enhanced CT is the diagnostic modality of choice. Typical findings include increased attenuation and thickening of mesenteric fat, sometimes accompanied by a “fat halo” or pseudocapsule.1,3–6 There is no consensus regarding invasive procedures, oncological screening, or follow-up strategies, leading to uncertainty in the management of incidental MP findings.2,5,7
This study aimed to describe the clinical, radiological, and prognostic characteristics of a single-center cohort of patients with MP and to compare primary and secondary forms in terms of associated conditions, presentation, and outcomes.
Materials and methodsStudy design and settingWe conducted a retrospective descriptive cohort study at the Hospital Universitario de San Juan (Alicante, Spain), including adult patients with MP followed in Internal Medicine outpatient clinics between January 2013 and January 2024.
Study population and inclusion criteriaEligible patients were adults (≥18 years) with a radiological diagnosis of MP, mainly based on contrast-enhanced abdominal CT, established either in Internal Medicine or after referral from other departments or primary care. All consecutive patients with MP followed in Internal Medicine during the study period were included, regardless of symptom burden or MP subtype. Patients who died during follow-up were retained, whereas only a very small number of individuals were lost to follow-up, mainly in relation to the COVID-19 pandemic.
DefinitionsMP was classified as primary when no associated condition potentially related to its development was identified. Secondary MP was defined by the presence of a clinically or temporally related malignancy, autoimmune disease, or infection.2–4,10
Data collectionData were collected retrospectively from electronic medical records using a standardized form. Variables included demographics, body mass index (BMI), smoking status, prior abdominal surgery or trauma, intestinal ischaemia, autoimmune diseases, infections, malignancy, clinical presentation, imaging findings, and outcomes. Clinical variables included abdominal pain, distension, weight loss, nausea, vomiting, bowel habit changes, anorexia, fever, palpable mass, and gastrointestinal bleeding.
Median follow-up was 6.5 years (interquartile range 4.0–9.0), with individual follow-up durations extending up to 12 years. Most patients were followed for 4-10 years, with only a small number of losses to follow-up, partly related to the COVID-19 pandemic.
OutcomesThe primary outcome was clinical course during follow-up (stability, improvement, worsening, death). Secondary outcomes included differences between primary and secondary MP in presentation, imaging findings, and mortality.
Statistical analysisContinuous variables are expressed as mean±standard deviation or median (interquartile range), and categorical variables as absolute and relative frequencies. Comparisons between primary and secondary MP used the Chi-square test for categorical variables and the T-test for continuous variables. Kaplan–Meier survival curves and the log-rank test were used to compare overall survival. Given the descriptive design and low number of events, analyses were unadjusted and considered exploratory. A p value of <0.05 was considered statistically significant.
ResultsBaseline characteristics, associated conditions and classificationA total of 111 patients with radiologically diagnosed MP were included. Women represented 50% of the cohort. Mean age at diagnosis was 72.2±13.1 years. Mean BMI was 31.5±3.7kg/m2, indicating frequent overweight or obesity. Current or former smoking was present in 40.5%. Previous abdominal surgery was reported in 40.5% of patients, abdominal trauma in 9.9%, and prior intestinal ischaemia in 3.6%.
MP was classified as primary in 61.3% (n=68) and secondary in 38.7% (n=43). Among secondary cases, MP was associated with infections in 21 patients (48.8%), with malignancies in 18 (41.9%) and with autoimmune diseases in 7 (16.3%). A history of malignancy was present in 19.8% of the overall cohort (Table 1).
Baseline characteristics of patients with primary and secondary MP. Data are expressed as mean (SD) or n (%), as appropriate.
| Variable | Primary MP(n=68) | Secondary MP(n=43) | p value |
|---|---|---|---|
| Female sex, n (%) | 34 (50.0) | 21 (48.8) | 0.90 |
| Age (years), mean±SD | 71.9±12.8 | 72.7±13.6 | 0.78 |
| BMI mean±SD, kg/m2 | 31.5±3.7 | 31.2±3.6 | 0.72 |
| Current or former smoker, n (%) | 28 (41.2) | 17 (39.5) | 0.86 |
| Previous abdominal surgery, n (%) | 27 (39.7) | 18 (41.9) | 0.81 |
| Abdominal trauma, n (%) | 7 (10.3) | 4 (9.3) | 0.86 |
| Intestinal ischaemia, n (%) | 3 (4.4) | 1 (2.3) | 0.55 |
| Autoimmune disease, n (%)* | 0 (0.0) | 7 (16.3) | <0.001 |
| Ulcerative colitis | 7 | ||
| Relevant infection, n (%)* | 0 (0.0) | 21 (48.8) | <0.001 |
| Helicobacter pylori infection | 19 | ||
| Tuberculosis | 1 | ||
| Rheumatic fever | 1 | ||
| Associated neoplasia, n (%)* | 0 (0.0) | 18 (41.9) | <0.001 |
| Breast cancer | 5 | ||
| Non-Hodgkin lymphoma | 4 | ||
| Gynaecological malignancy | 3 | ||
| Prostate cancer | 2 | ||
| Colorectal cancer | 2 | ||
| Primary brain tumour | 2 | ||
*By definition, associated neoplasia, relevant infection and autoimmune disease are concentrated in the secondary MP group.
At diagnosis, 31.5% of patients were asymptomatic, with MP detected incidentally. Abdominal pain was the most frequent complaint. Clinical presentation was broadly similar between primary and secondary MP, although there was a trend towards greater symptom burden and more frequent weight loss in secondary forms (Table 2).
Clinical presentation and clinical course in patients with primary and secondary MP. Data are expressed as n (%). Comparisons between primary and secondary MP were performed using unadjusted Chi-square tests and should be interpreted as exploratory.
| Variable | Primary MP(n=68) | Secondary MP(n=43) | p |
|---|---|---|---|
| Asymptomatic at diagnosis, n (%) | 24 (35.3) | 11 (25.6) | 0.25 |
| Abdominal pain, n (%) | 36 (55.4) | 27 (64.3) | 0.36 |
| Abdominal distension, n (%) | 16 (24.6) | 7 (16.7) | 0.32 |
| Weight loss, n (%) | 5 (7.7) | 8 (19.0) | 0.07 |
| Nausea, n (%) | 8 (12.3) | 3 (7.1) | 0.39 |
| Vomiting, n (%) | 2 (3.1) | 2 (4.8) | 0.65 |
| Bowel habit change, n (%) | 1 (1.5) | 2 (4.8) | 0.32 |
| Anorexia, n (%) | 2 (3.1) | 1 (2.4) | 0.83 |
| Fever, n (%) | 1 (1.5) | 0 (0.0) | 0.46 |
| Palpable abdominal mass, n (%) | 1 (1.5) | 1 (2.4) | 0.75 |
| Clinical stability, n (%) | 59 (86.8) | 36 (83.7) | 0.64 |
| Clinical improvement, n (%) | 3 (4.4) | 1 (2.3) | 0.55 |
| Clinical worsening, n (%) | 1 (1.5) | 2 (4.7) | 0.32 |
| Deaths during follow-up, n (%) | 5 (7.4) | 4 (9.3) | 0.72 |
CT was the diagnostic cornerstone in all patients. In 53.6%, both ultrasound and CT were performed, while 41.8% were diagnosed based on CT alone. Mesenteric thickening was the most frequent finding, present in 86.8% of cases. Calcifications were reported in 17.9% and mesenteric lymphadenopathy in 9.5%. More specific signs such as the fat halo were less frequently described.
Clinical course and outcomesOver a median follow-up of 6.5 years (interquartile range 4.0–9.0), most patients remained clinically stable (85.6%), 3.6% improved, 2.7% worsened and overall mortality was 8.1%, with similar clinical stability in primary and secondary forms.
All secondary MP cases received aetiology-directed treatment according to the underlying condition, whereas most primary MP cases were managed conservatively or with symptomatic treatment. Four primary cases treated with a short course of oral corticosteroids achieved complete clinical and radiological response, and three untreated cases showed spontaneous resolution on follow-up CT.
Mortality was numerically higher in secondary MP, particularly when malignancy was present; however, Kaplan–Meier analysis showed no statistically significant differences in overall survival between groups (log-rank p=0.65) (Fig. 1).
Kaplan–Meier survival curves for primary and secondary mesenteric panniculitis (MP) showing cumulative survival over 12 years. Overall survival was high in both groups, with no statistically significant differences (log-rank p=0.65). Vertical markers (+) indicate censored observations; the table below the x-axis displays the number of patients at risk at each time point.
This single-center clinical cohort with long-term follow-up shows that MP predominantly affects older adults, with a balanced sex distribution and a substantial proportion of primary cases, consistent with previous reports.1–3,5,8 Secondary MP was commonly associated with infections, malignancy or autoimmune diseases, but the lack of significant differences in overall survival between primary and secondary forms suggests that MP itself is unlikely to behave as a uniformly paraneoplastic process; rather, prognosis appears to be driven mainly by the underlying associated condition.4,5,8–10
Approximately one third of patients were asymptomatic at diagnosis, and abdominal pain was the most frequent symptom in symptomatic cases, in line with prior studies.2,5,8 Imaging findings were predominantly characterized by mesenteric thickening, whereas more specific CT features were less commonly reported, likely reflecting routine clinical practice and highlighting the need for more standardized imaging criteria.1,3–6
The overall clinical course was predominantly stable, particularly in primary MP, with low mortality. These findings support a conservative management approach in asymptomatic patients and those with primary disease, while favouring a targeted and context-driven evaluation in secondary forms or when clinical features raise concern.2,4–6,8–10
Strengths of this study include the consecutive inclusion of patients in a real-world Internal Medicine setting, long follow-up, and systematic collection of clinical, imaging, and outcome data, together with the explicit comparison of primary and secondary MP using consistent clinical definitions. Limitations include the retrospective, single-centre design, the lack of standardized imaging protocols, the limited number of events and the absence of adjusted analyses. Moreover, within secondary MP we did not systematically differentiate between cases in which MP was an incidental finding in patients with established disease and those in which it contributed more directly to diagnosing the associated condition, so potential prognostic differences between these scenarios could not be assessed. Prospective studies with standardized methodologies are therefore needed to clarify these aspects.
ConclusionsMP predominantly affects older adults, with many primary cases following an indolent clinical course and most patients remaining clinically stable over time. Secondary MP is more often associated with infections, malignancy, or autoimmune diseases, and tends to present with a higher symptom burden, although survival did not differ significantly between primary and secondary forms in this cohort. These findings support distinguishing primary from secondary MP and provide practical guidance for internists.
Ethical considerationsThis study was approved by the research ethics committee of Hospital Universitario de Sant Joan d’Alacant (approval code 15/303) and was conducted in accordance with the principles of the Declaration of Helsinki. Given its retrospective design and the exclusive use of anonymized clinical data, the committee waived the requirement for individual informed consent.
FundingThis research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.
Conflict of interestThe authors declare that they have no conflicts of interest related to this work.
