Whipple's disease
The ultrasound features were highly suggestive of malabsorption, a hypothesis that was supported by the laboratory findings. Celiac disease, one of the most common causes of malabsorption, was excluded by serology tests. Esophagogastroduodenoscopy was therefore repeated: The mucosa of the distal first part and second part of the duodenum appeared completely covered with tiny white spots (Figure C). Histologic examination revealed that the mucosal architecture of the villi was altered by the presence of infiltrates of macrophages with wide cytoplasm filled with round periodic acid-Schiff (PAS)-positive inclusions, associated to aggregates of neutrophils attacking the epithelium (Figure D). These histologic findings are consistent with Whipple's disease.
Whipple's disease is a chronic infectious disease caused by a gram-positive ubiquitous bacterium named Tropheryma whipplei . In predisposed subjects with an insufficient T-helper response, for example, those undergoing treatment with tumor necrosis factor-alpha inhibitors as in our patient, T. whipplei is able to survive and replicate inside the macrophages of the intestinal mucosa and to spread to other organs.1 Whipple's disease can thus manifest as a multisystemic disease or as a single-organ disease with extraintestinal involvement (e.g., central nervous system, eyes, heart, or lung). The classic form is characterized by weight loss, diarrhea, abdominal pain, and signs of malabsorption, typically preceded by a history of arthralgia. The arthralgia is often misdiagnosed as a form of rheumatoid arthritis and therefore treated with immunosuppressant therapy, which favors the onset of the classic intestinal symptoms.
In the literature, few case reports describe the ultrasound findings in patients with Whipple's disease. The most frequent sonographic features include small-bowel dilatation with wall thickening, the presence of peri-intestinal fluid effusion and mesenteric and retroperitoneal lymphadenopathy.2,3
The final diagnosis relies on intestinal biopsy and the histologic finding of foamy macrophages containing large amounts of diastase-resistant PAS-positive particles in the lamina propria of the duodenum, jejunum, ileum, or gastric antral region.
The diagnosis, particularly in cases of extraintestinal involvement, can be confirmed by polymerase chain reaction positivity for T. whipple i in the examined tissue.
Therapy consists of the administration of ceftriaxone (2 g IV once daily) for 2 weeks followed by oral therapy with trimethoprim-sulfamethoxazole for 1 year.
References
1. Schneider T et al. Whipple's disease: New aspects of pathogenesis and treatment. Lancet Infect Dis. 2008;8:179-90.
2. Brindicci D et al. Ultrasonic findings in Whipple's disease. J Clin Ultrasound. 1984;12:286-8.
3. Neye H et al. Der Morbus Whipple's Disease - A rare intestinal disease and its sonographic characteristics. Ultraschall Med. 2012;33(04):314-5.
