Is Pneumatosis Cystoides Intestinalis Gas-Distended and Ruptured Lymphatics?: Reappraisal by Immunohistochemistry

Abstract

Context.-Pneumatosis cystoides intestinalis (PCI) is a condition with multiple gas-filled cysts within the bowel wall, associated with diverse background diseases. Its pathogenesis is still a mystery. Some previous observations scattered in the literature have suggested an association of the cystic spaces in PCI with the lymphatics.Objective.-To further investigate whether PCI results from the ballooning of gas-filled lymphatic channels.Design.-We did immunostaining of podoplanin, a mucoprotein preferentially expressed in lymphatic endothelial cells, in 13 cases (8 men, 5 women; age range, 18-80 years) of PCI. Ten cases were diagnosed in resected segments of bowel and 3 in biopsies. Pneumatosis was seen in the right side of the colon (9 cases), transverse colon (1 case), sigmoid colon (1 case), and small bowel (2 cases). In addition, immunostaining for CD31, calretinin, WT1, CD68, smooth muscle actin, desmin, vimentin, and cytokeratins was also performed for comparison and correlation.Results.-A strong immunopositivity of podoplanin was seen in a condensed linear structure in the pericystic interstitium in 100% of the cases, but was not seen in the overlying giant and flat cells that were all CD68-positive histiocytes. Meanwhile, the podoplanin-expressing structure was negative for calretinin and WT1, which ruled out the possible mesothelial origin. There were coexistent variable immunopositivity of smooth muscle actin, which suggests an admixture of myofibroblasts. These findings indicated that the PCI cases were gas-distended lymphatics with the lymphatic epithelium ruptured and embedded in the reactive histiocytes and giant cells.Conclusion.-Our findings support the lymphatic theory about the pathogenesis of PCI.

The Eyes Do Not See What the Mind Does Not Know: An Underreported Feature in Mature Cystic Teratoma of the Ovary

“…Pneumatosis cystoides intestinalis (PCI) was first coined by Mayer in 1825 describing a rare phenomenon with unknown aetiology occurring in the intestine. It is characterised by the presence of multiple gas-filled cysts containing hydrogen, nitrogen and carbon dioxide within the submucosal and subserosal region of the intestine (Gui et al 2014). These optically "empty" cysts are typically lined by variable amount of foreign body type multinucleated giant cells, epithelioid macrophages and/or flattened cells of histiocytic in origin (Gui et al 2014).…”

“…While PCI is notorious to cause complications related to the ruptured of its gaseous content including pneumoperitoneum, tension pneumoperitoneum and intussusception (Gui et al 2014), little is known about the prognostic implication of these pneumatosis cystoides-like spaces within the tumour since it is an infrequently reported phenomenon. Whether it denotes a mere incidental histological finding with no prognostic value awaits further study.…”

Acute pneumatosis cystoides intestinalis with atrophic desmosis of the colon in a child

“…PCI has been described as occurring 2–3 months after allogeneic stem cell transplantation in patients requiring chronic steroid treatment for GvHD 1 2. Passage of intraluminal gas into the submucosa requires a damaged muscularis mucosae, which may occur during the course of an inflammatory process or in conjunction with an anatomical defect such as alteration of lymphoid follicles by steroid-induced lymphocyte depletion 6. The right colon, which is known to be more susceptible to ischaemia than other segments of the colon, is more frequently affected in PCI in immunosuppressed patients.…”

The appearance of free-air in the abdomen with related pneumatosis cystoides intestinalis: Three case reports and review of the literature

“…Treatment of PSI depends on the underlying cause, so that include elemental diet, antibiotics, steroids, hyperbaric oxygen therapy and surgery. 3,7,8,11,12,15–17 In asymptomatic patients with free-air at X-ray and abdominal CT reporting gastrointestinal perforation direction, is a great handicap for the surgeon. So we should be careful in the diagnosis of disease.…”