Lymphocytic ("microscopic") colitis: a comparative histopathologic study with particular reference to collagenous colitis

Lymphocytic colitis, previously termed "microscopic colitis", is a clinicopathologic syndrome of watery diarrhea, grossly normal colonoscopy, and mucosal inflammatory changes. Since lymphocytic colitis is a new, incompletely characterized entity, a histopathologic study was performed to compare lymphocytic colitis (n = 16), collagenous colitis (n = 17), idiopathic inflammatory bowel disease (n = 16), acute colitis (n = 16), and histologically normal colon (n = 12). The study was a blinded semiquantitative analysis of histologic features in the surface epithelium, lamina propria, and crypts. The most distinctive feature of lymphocytic colitis was increased intraepithelial lymphocytes, particularly in the surface epithelium (P = .0001 v idiopathic inflammatory bowel disease, acute colitis, and normal colon). Other prominent features of lymphocytic colitis included surface epithelial damage (P less than .005 v idiopathic inflammatory bowel disease and normal colon), increased lamina propria chronic inflammation (P less than .01 v normal), and minimal crypt distortion or active cryptitis. There were striking similarities between lymphocytic colitis and collagenous colitis, but subepithelial collagen thickening was seen only in collagenous colitis. Idiopathic inflammatory bowel disease showed prominent crypt distortion and greater active inflammation, in addition to minimal intraepithelial lymphocytes. Acute colitis occasionally demonstrated prominent surface epithelial damage, but was otherwise dissimilar from lymphocytic colitis. We reached the following conclusions: (1) the entity "microscopic colitis" shows characteristic histopathology including prominent lymphocytic infiltration of epithelium, and thus, a more appropriate designation is lymphocytic colitis; (2) although lymphocytic colitis closely resembles collagenous colitis, each entity is distinct on biopsy; and (3) lymphocytic colitis is readily distinguishable from idiopathic inflammatory bowel disease, acute forms of colitis, and normal colorectum.

Bladder involvement in Crohn disease: role of CT in detection and evaluation

A retrospective review of 275 consecutive patients with symptomatic Crohn disease to determine the frequency and type of bladder involvement yielded 14 cases. All 14 patients had a long standing history of Crohn disease with other positive radiologic features at the time of detection of bladder involvement. Patients were categorized into two groups based on the CT findings: Group I (n = 4) had focal bladder wall thickening adjacent to an extravesical soft tissue mass and/or focal bowel wall thickening; Group II (n = 10) had fistula formation with intravesical air with associated focal bowel wall thickening and/or extravesical soft tissue mass. Bladder involvement in Crohn disease is a progressive pathological process that can result in formation of an enterovesical fistula. The patient may come to radiologic attention at any stage in the course of the disease. Computed tomography is a sensitive and noninvasive method of evaluating the bladder and can be used to identify patients in the prodromal stage who are at risk of developing enterovesical fistulae. Timely intervention may prevent frank perforation into the lumen of the bladder by an inflammatory mass.

Decreased height velocity in children and adolescents before the diagnosis of Crohn's disease

Severe linear growth retardation occurs in 20%-30% of children with Crohn's disease, yet, it is unknown how often decreased height velocity precedes the diagnosis. The height velocities of 50 children and prepubescent adolescents with Crohn's disease were reviewed. Decreased height velocity antedated the diagnosis in 44 patients. Twenty-one patients had a reduction in height velocity before intestinal symptoms were noted. Additionally, 17 of 32 patients with attenuated linear growth had a reduction in height velocity before any weight loss. Linear growth impairment in Crohn's disease, more common than previously recognized, may precede weight loss and can be the earliest indicator of disease.

Granular small bowel mucosa: a reflection of villous abnormality

Diffuse mucosal granularity was reported recently in small bowel Crohn's disease. The radiographic appearance corresponded on histopathologic examination to villous hypertrophy, fusion, or epithelial bridge formation. We have observed similar granularity in Crohn's disease but also in several other conditions, including radiation enteritis, pancreatic glucagonoma, protein-losing enteropathy, and small bowel ischemia. Histopathologic examination demonstrated various alterations in villous morphology, such as edema, hyperplasia, clubbing, or fusion. In Crohn's disease, this appearance was sometimes an indication of early inflammatory disease but was also seen following extensive small bowel resection, possibly due to villous enlargement resulting from intestinal adaptation. These findings suggest that granular mucosa in the small bowel is a nonspecific finding reflecting an alteration in villous structure.

Computed tomography vs barium studies in the acutely symptomatic patient with Crohn disease

Gastrointestinal contrast studies and CT performed on 43 patients with known Crohn disease with acute symptoms were retrospectively reviewed to assess the ability of each study to define the location and extent of disease. In 39 of 43 (91%) patients the contrast studies and CT agreed on the location of active disease. However, in 15 of 43 (35%) patients, contrast studies demonstrated additional areas of mucosal disease remote from the major area of activity that were not suggested by CT. In addition to demonstrating more extensive mucosal disease, contrast studies proved superior in demonstrating enteroenteric fistulae, sinus tracts, strictures, postsurgical anatomy, and relation of recurrence to anastomosis. Computed tomography proved superior in demonstrating mesenteric inflammation, abscesses, enterovesical and enterocutaneous fistulae, fistula to iliopsoas muscle and to sacrum. We conclude that in the patient with suspected abscess, enterovesical or enterocutaneous fistula, CT is the study of choice. In other clinical circumstances both CT and contrast studies should be performed since they are complementary.

Chronic colitis with thickening of the subepithelial collagen layer (collagenous colitis): histopathologic findings in 15 patients

The histopathologic features of collagenous colitis were studied in 14 women and one man. All but one patient presented with chronic watery diarrhea: 10 had a history of thyroid disease or unspecified arthritis. All 15 patients showed characteristic thickening of the subepithelial collagen layer (SCL) in colorectal biopsy specimens, but in the distal colorectum the thickening was sometimes absent or borderline. Patchy or diffuse injury to the surface epithelium was seen in all cases and was independent of SCL thickening. The injured surface epithelium was infiltrated by lymphocytes and variably by eosinophils and neutrophils, causing it to resemble the surface epithelial injury seen in the small intestine in celiac disease. Crypts were commonly infiltrated by lymphocytes but without associated epithelial injury. The lamina propria in all patients was expanded by lymphocytes, plasma cells, and eosinophils. Neutrophilic cryptitis was seen in seven patients but was usually sparse. Watery diarrhea abated in eight patients treated with corticosteroids or sulfasalazine and was often paralleled by restoration of surface epithelium, reduction in surface epithelial lymphocytes, diminished SCL thickening, and reduced lamina propria eosinophils. Therapy did not consistently alter other inflammatory changes. The possible role of autoimmunity in collagenous colitis should be investigated because of the following circumstantial evidence: the overwhelming female predominance; the frequent presence of possible immunologically mediated disorders such as thyroid and joint disease; the resemblance of surface epithelial changes to those in celiac disease; and the response to corticosteroids.

CT evaluation of Crohn's disease: effect on patient management

CT scans from 80 consecutive patients with clinically symptomatic Crohn's disease were reviewed retrospectively to determine the effect of CT diagnosis on patient management. The initial clinical impression and any subsequent change in patient management because of the CT findings were noted. In 22 (28%) of the 80 patients, significant previously unsuspected findings led to a change in medical or surgical management. These included 12 patients with fistulae, four with abscess, two with avascular necrosis of the femoral head, two with sacral osteomyelitis, and single cases of pelvic inflammatory disease and femoral vein thrombosis.

Collagenous colitis: physiologic and histopathologic studies in seven patients

Collagenous colitis is a clinicopathologic syndrome with chronic watery diarrhea, diffuse colitis with surface epithelial injury, and a distinctive collagen band beneath the surface epithelium especially in the proximal colon. The cases of seven patients (including six middle-aged women) with chronic, watery, noninfectious diarrhea were studied. Roentgenographic and endoscopic findings were not diagnostic. Two patients had rectal mucosal inflammation but sparing of the distal colon from subepithelial collagen. Other findings included thyroid disease (four patients), urethral fibrosis (three), elevated erythrocyte sedimentation rate (six), and eosinophilia (three). The colon was thought to be the main source of diarrheal fluid, but bile salt malabsorption, steatorrhea, and net small-bowel secretion were additive factors in some patients. With antiinflammatory treatment the diarrhea abated, the surface epithelial injury decreased, and the subepithelial collagen resolved (two patients), but lamina propria inflammation persisted. Collagenous colitis seems to be a chronic systemic, and perhaps autoimmune, disorder.

Submucosal accumulation of fat in inflammatory bowel disease: CT/pathologic correlation

A prominent submucosal layer of decreased attenuation was demonstrated on CT in three patients with inflammatory bowel disease. On pathologic examination this zone proved to be due to extensive submucosal fat accumulation and not active inflammation. The potential significance of this finding is discussed.

The role of resection margin frozen section in the surgical management of Crohn's disease

The use of frozen section examination of resection margins in selecting the site for an ileocolonic anastomosis was evaluated in patients with Crohn's disease. Seventy-nine patients with ileitis or ileocolitis who underwent first resection with removal of all apparent disease and primary ileocolonic anastomosis were studied. The patients with a resection margin examined by frozen section (FS group, n = 38) and those with margins chosen on the basis of visual inspection alone (NO-FS group, n = 41) were compared. Frozen section examination was found to be poor at detecting margin involvement: although 60 of 61 margins examined by frozen section were reported as negative at the time of operation, 20 of 61 were actually involved by Crohn's disease. Furthermore, despite the use of frozen section examination, the prevalence and severity of margin involvement in the FS and NO-FS groups were not statistically significantly different. Short term and long term clinical outcome were also not statistically different; the incidence of postoperative anastomotic leakage and obstruction was 13 per cent in the FS group and 5 per cent in the NO-FS groups (p NS). Clinical recrudescence rates by life table analysis in the FS and NO-FS groups were 37 +/- 9 per cent and 50 +/- 8 per cent, respectively, at five years, and 60 +/- 12 per cent and 66 +/- 9 per cent at ten years (p NS). Reoperation rates were 18 +/- 8 per cent at five years in both groups and 36 +/- 13 per cent in the FS group and 32 +/- 12 per cent in the NO-FS group at ten years. The findings support conservative resection to achieve grossly uninvolved margins rather than sacrifice of functional intestine in an attempt to achieve histopathologically uninvolved margins on frozen section.

Lymphadenopathy in celiac disease: computed tomographic observations

Lymphadenopathy in patients with celiac disease is generally viewed with alarm due to the association between celiac disease and intestinal lymphoma. Four patients with celiac disease are described in whom significant mesenteric and paraaortic adenopathy was demonstrated by computed tomography (CT). The subsequent clinical course of these patients revealed no evidence of lymphoma. In two patients with longstanding celiac disease and recent relapse, exploratory laparotomy revealed reactive hyperplasia in the enlarged glands; in one patient this was associated with intestinal ulceration, and in the other no underlying pathology was found. Follow-up CT scans in both these patients demonstrated regression of the findings with clinical improvement. In the other two patients, CT was performed as part of the initial evaluation. Follow-up CT in one of these patients revealed almost complete regression of the adenopathy after institution of a gluten-free diet. The other, with a 2 year duration of CT-documented abdominal adenopathy prior to diagnosis, became asymptomatic with weight gain for over 1 year after institution of a gluten-free diet.

"Bubbly" duodenal bulb in celiac disease: radiologic-pathologic correlation

Small (1-4 mm) hexagonal filling defects were found on air-contrast studies of the duodenal bulb in three patients with unresponsive (atypical) celiac disease. Multiple biopsies confirmed both celiac disease and peptic duodenitis. Stimulated acid outputs determined in two patients were in the peptic ulcer range. Cimetidine therapy led to improved absorption in all three patients. Repeat upper gastrointestinal series and endoscopy in one patient showed no evidence of nodularity or peptic duodenitis, indicating that these changes may be reversible. Peptic disease may contribute to nodularity in the duodenal bulb and relative lack of response to a gluten-free diet of some patients with celiac disease. The finding of tiny nodules in the duodenal bulb in a patient with malabsorption should lead to consideration of celiac disease as a primary diagnosis with peptic duodenitis as an aggravating factor.

Crohn's disease of the colon. Is there a role for limited resection?

Forty-one patients underwent resection for Crohn's disease of the large bowel. Twelve patients had a total proctocolectomy for diffuse disease of the colon and rectum, and 29 patients with segmental disease of the large bowel underwent limited resection. Thirteen of the 29 patients had a subtotal colectomy, with 7 patients undergoing immediate ileoproctostomy and 6 having an ileostomy. Further surgery was required in 9 f the 13 patients, and long-term enteric continuity was maintained in only 3 patients. Sixteen patients with more localized Crohn's disease of the colon underwent segmental resection. Seven patients required additional surgery, and enteric continuity was restored in 12 of the 16 patients. There was no mortality among these 29 patients. This study suggests that Crohn's disease of the colon may be successfully treated by limited resection when involvement is segmental. In the patient with more extensive disease of the colon with only rectal sparing, morbidity is high and the probability of maintaining enteric continuity is low. Therefore, in these patients total proctocolectomy should be considered.

Plasma postheparin diamine oxidase. Sensitive provocative test for quantitating length of acute intestinal mucosal injury in the rat

Diamine oxidase (DAO; EC 1.4.3.6) is an enzyme found in high activity in the mature cells of the upper villus of rat small intestinal mucosa and in very much lower activity in all other tissues in the nonpregnant rat. This study was designed to determine whether a provocative test for increasing the level of plasma DAO activity by heparin administration could be used to monitor the extent and severity of acute, severe, small intestinal mucosal injury. In adult rats, small intestinal loops of varying lengths were perfused with 2,100 mosM sodium sulfate solution for 60 min to produce selective damage to villus epithelium. Plasma postheparin DAO (PHD) activity (180 min after 400 U/kg i.p. heparin) was measured 7 h after initiation of perfusion. With increasing length of intestinal mucosal injury, there was a progressive decrease in both basal and plasma PHD activity. The decrease in plasma PHD activity closely reflected the length of intestinal mucosa injured (n = 128, r = 0.86, P less than 0.001), and it was much more sensitive (threshold limit of detection = 13% of total length, range = 67 U/ml for 100% length of injury) than unstimulated basal levels of plasma DAO (threshold = 40%, range = 2.1 U/ml). Our previous data have suggested that DAO is unique among intestinal mucosal enzymes in that circulating levels can serve as a marker of mucosal injury; this study illustrates that the addition of a low-dose heparin administration enhances the use of DAO even further as a sensitive, quantitative, circulating marker for monitoring the extent of small intestinal mucosal injury in the rat.

Villous hypertrophy of the small bowel in a patient with glucagonoma

Mucosal thickening in the small bowel was seen on computed tomography (CT) in a patient with a pancreatic glucagonoma. A small bowel series demonstrated multiple fine filling defects throughout both jejunum and ileum associated with moderate fold thickening and prolonged transit time. Villous hypertrophy was indeed identified in a resected segment of jejunum. Elevated blood levels of enteroglucagon have previously been associated with small intestinal villous hypertrophy. Careful scrutiny of the bowel pattern on CT scans may suggest abnormalities which may then be confirmed by conventional barium studies. Such observations may change the evaluation of a clinical problem.

Fructose: incomplete intestinal absorption in humans

Fructose is an increasingly important commercial sweetener. However, some patients report abdominal symptoms after ingesting fructose-containing foods. The completeness of fructose absorption by the small intestine was assessed by breath hydrogen analysis in 16 healthy volunteers and incomplete absorption was defined as a peak rise in breath hydrogen of greater than 20 parts per million. Fructose, 50 g as a 10% solution, was incompletely absorbed in 6 of 16 subjects (37.5%). Incomplete absorption was associated with symptoms of cramps or diarrhea, or both in 5 of these 6 individuals. Incomplete absorption was both concentration- and dose-related. Three subjects incompletely absorbed 37.5 g of fructose. In comparison, all 15 subjects who were studied after ingestion of sucrose, 50 g and a 10% solution, completely absorbed this sugar load. Incomplete absorption of fructose should be considered as a possible case of gastrointestinal symptoms.

Fructose: incomplete intestinal absorption in humans

Fructose is an increasingly important commercial sweetener. However, some patients report abdominal symptoms after ingesting fructose-containing foods. The completeness of fructose absorption by the small intestine was assessed by breath hydrogen analysis in 16 healthy volunteers and incomplete absorption was defined as a peak rise in breath hydrogen of greater than 20 parts per million. Fructose, 50 g as a 10% solution, was incompletely absorbed in 6 of 16 subjects (37.5%). Incomplete absorption was associated with symptoms of cramps or diarrhea, or both in 5 of these 6 individuals. Incomplete absorption was both concentration- and dose-related. Three subjects incompletely absorbed 37.5 g of fructose. In comparison, all 15 subjects who were studied after ingestion of sucrose, 50 g and a 10% solution, completely absorbed this sugar load. Incomplete absorption of fructose should be considered as a possible case of gastrointestinal symptoms.

Crohn's disease: are enteroenteral fistulas an indication for surgery?

Currently many physicians consider enteroenteral fistulas an indication for surgery in Crohn's disease. In an attempt to document the natural history of these fistulas, the courses of 64 patients with Crohn's disease complicated by enteroenteral fistulas were reviewed. The fistulas were diagnosed radiologically in 48 patients (75%) and at operation or by examination of the resected specimen in 16 (25%). Twenty-four of the 48 patients whose fistulas were diagnosed radiologically underwent early operation. The remaining 24 initially had nonoperative management and thus provided information about the natural history of enteroenteral fistulas. Ten of these 24 patients had nonoperative treatment for less than 1 year. All required surgery because of intestinal obstruction, enterovesical fistula, or failed response to medical therapy. Fourteen patients were managed nonoperatively for a mean period of 3.5 years (range 1 to 9 years). Eight of these patients eventually required operation, but the remaining six have to date not needed surgery. In two of these patients the fistulas can no longer be demonstrated radiographically. Patients who initially received nonoperative therapy and later required operation did not have any increased mortality or morbidity as compared with those treated with early surgery. Enteroenteral fistulas are frequently associated with and are the result of active inflammatory disease. The fistulas are usually asymptomatic and are by themselves not considered an indication for operation.

Surgical management of Crohn's disease. Influence of disease at margin of resection

To determine the influence of microscopic disease at an anastomosis following intestinal resection for Crohn's disease, 97 patients undergoing 103 resections were reviewed. Most resections (85/103) involved both small and large bowel and were followed by an ileocolic anastomosis. All resection margins were available and were reviewed. In 52 instances there was no evidence of Crohn's disease at the margins. In 51 instances histologic evidence of Crohn's disease varying from chronic inflammation to tissue destruction was present in one or both margins. The incidence of immediate postoperative anastomotic complications (leak with fistula or abscess, or obstruction) was identical in patients with microscopically normal margins (3/52; 6%) and in patients with microscopic Crohn's disease at the margins (3/51; 6%). The patients were followed for a mean of 5.4 +/- 4.2 years. A clinical recurrence developed during the follow-up period in 50% (26/52) of those patients with normal margins, and in 61% (31/51) of those patients with involved margins. A suture line recurrence developed in 35% (18/52) and required reoperation in 17% (9/52) of those patients with microscopically normal margins. A suture line recurrence developed in 41% of the patients (21/51) and required reoperation in 24% (12/51) of those with microscopically involved margins. None of these differences are statistically significant. The presence or absence of microscopic disease at the anastomosis did not appear to influence immediate anastomotic wound healing or long-term recurrence rates. We therefore recommend conservative resections for Crohn's disease to achieve grossly uninvolved margins rather than the sacrifice of normal bowel to achieve histologically normal margins.