Pernicious anemia and widespread absence of gastrointestinal endocrine cells in a patient with autoimmune polyglandular syndrome type I and malabsorption.

CONTEXT: Autoimmune polyglandular syndrome type I (APS I) is characterized by multiple endocrine gland failures, with other manifestations such as gastrointestinal (GI) symptoms. OBJECTIVE: The objective of the study was to study the histopathological and immunological findings in the GI mucosa of a patient with typical features of APS I, malabsorption, and pernicious anemia. DESIGN AND PATIENT: Biopsies from the GI tract of a patient with APS I were immunostained with chromogranin for GI endocrine cells (GIECs). Blinded slides were graded for numbers of endocrine cells. Normal gastric mucosa was exposed to the patient's serum to test for circulating anti-GIEC and antiparietal cell antibodies using indirect immunofluorescence. SETTING: The study was conducted at the Departments of Pediatrics and Medical Gastroenterology in an academic medical center. RESULTS: The patient's GI mucosa demonstrated absence of GIECs throughout, including gastric gastrin-secreting cells, and her laboratory tests for serum gastrin levels were low normal. Both GIECs and parietal cells were absent in her gastric corpus. The patient's serum contained anti-GIEC antibody but no antiparietal cell antibody. CONCLUSIONS: These observations suggest that GIECs in APS I are subject to an autoimmune destruction that can cause widespread GIEC loss. This could explain the GI dysfunctions that are often noted in the syndrome including malabsorption and atrophic gastric changes with pernicious anemia. We also hypothesize that absence of gastric parietal cells may result mainly from hypogastrinemia that is mainly the loss of gastrin-secreting cells rather than from immune-mediated destruction of parietal cells like that seen in the atrophic gastritis associated with adult-onset pernicious anemia.

Cerebral ocular Whipple's disease: a 62-year odyssey from death to diagnosis.

A 47-year-old white man with dementia, supranuclear ophthalmoplegia, and myoclonic ocular and facial jerks died in 1931. The case report in 1936 by Ford and Walsh diagnosed encephalitis. In 1993, we made a clinical diagnosis of Whipple's disease on the basis of the 1936 publication. We restudied the pathologic material and found, in addition to extensive encephalitis, PAS-positive material in only the eye, brain, spinal cord, and pituitary. Electron microscopy demonstrated free and intracytoplasmic microorganisms in the eye and brain. We review the history of cerebral ocular Whipple's disease and the implications from this case, which occurred before the development of antibiotics.

Campylobacter pylori: a newly recognized infectious agent in the gastrointestinal tract.

Recent experience with the gastritis-associated organism Campylobacter pylori is reviewed, placing special emphasis on pathologic aspects. C. pylori is a spiral, gram-negative, urease-producing bacillus that has been found to infect the stomach in many people. C. pylori organisms are readily seen overlying the gastric epithelium, often in large numbers. Demonstration in gastric biopsies with silver stains is most vivid, but other faster, simpler stains such as Giemsa, acridine orange, and, at times, hematoxylin-eosin are satisfactory for routine purposes. The frequent occurrence of C. pylori in persons with chronic active gastritis has been confirmed in medical centers around the world. In addition, epidemiological, serological, pathological, and clinical observations suggest that C. pylori infection occurs in stomachs of duodenal ulcer patients with a frequency approaching 100%, and the infection may be relevant to pathogenesis or therapeutic response in duodenal ulcer disease. C. pylori probably also causes an acute infectious gastritis associated with hypochlorhydria. C. pylori still requires extensive investigation to establish its pathogenic role in upper gastrointestinal disorders, but evidence continues to accumulate that such a role exists and that it may be important.

Classification and grading of gastritis. The updated Sydney System. International Workshop on the Histopathology of Gastritis, Houston 1994.

The Sydney System for the classification of gastritis emphasized the importance of combining topographical, morphological, and etiological information into a schema that would help to generate reproducible and clinically useful diagnoses. To reappraise the Sydney System 4 years after its introduction, a group of gastrointestinal pathologists from various parts of the world met in Houston, Texas, in September 1994. The aims of the workshop were (a) to establish an agreed terminology of gastritis; (b) to identify, define, and attempt to resolve some of the problems associated with the Sydney System. This article introduces the Sydney System as it was revised at the Houston Gastritis Workshop and represents the consensus of the participants. Overall, the principles and grading of the Sydney System were only slightly modified, the grading being aided by the provision of a visual analogue scale. The terminology of the final classification has been improved to emphasize the distinction between the atrophic and nonatrophic stomach; the names used for each entity were selected because they are generally acceptable to both pathologists and gastroenterologists. In addition to the main categories and atrophic and nonatrophic gastritis, the special or distinctive forms are described and their respective diagnostic criteria are provided. The article includes practical guidelines for optimal biopsy sampling of the stomach, for the use of the visual analogue scales for grading the histopathologic features, and for the formulation of a comprehensive standardized diagnosis. A glossary of gastritis-related terms as used in this article is provided.

Erosive injury to the upper gastrointestinal tract in patients receiving iron medication: an underrecognized entity.

Severe gastrointestinal necrosis and strictures after an iron overdose are well described. However, mucosal injury in patients receiving therapeutic iron has received only scant recognition despite its wide use. We studied the clinical and histologic features of 36 upper gastrointestinal tract biopsies from 33 patients (24 gastric, 9 esophageal, 1 gastroesophageal junction, and 2 duodenal) containing characteristic brown crystalline iron material, and evaluated the amount and tissue distribution of the iron. In addition, we investigated the prevalence of iron-associated mucosal injury in upper gastrointestinal endoscopic examinations. The majority of the biopsies (32 of 36, 89%) contained luminal crystalline iron adjacent to the surface epithelium or admixed with luminal fibrinoinflammatory exudate. Thirty biopsies (83%) showed crystalline iron deposition in the lamina propria, either covered by an intact epithelium, subjacent to small superficial erosions, or admixed with granulation tissue. Three biopsies (8%) demonstrated iron-containing thrombi in mucosal blood vessels. Erosive or ulcerative mucosal injury was present in 30 of 36 biopsies (83%). The amount of iron accumulation in cases with mucosal injury was greater than in cases without mucosal injury (mean grades, 2.4+ vs. 1.3+ on a 1+ to 3+ scale; p = 0.002). Iron medication was confirmed in 25 of 33 patients (76%) 22 patients were receiving ferrous sulfate. Approximately half of the patients (17 of 33, 51%) also had underlying infectious, mechanical, toxic, or systemic medical conditions that could have initiated or exacerbated tissue injury. Crystalline iron deposition was found in 0.9% of upper gastrointestinal endoscopic examinations (12 of 1,300), and iron medication-associated erosive mucosal injury was present in 0.7% (9 of 1,300). These results indicate that crystalline iron deposition in the upper gastrointestinal tract is not uncommon. It can induce or exacerbate a distinctive histologic pattern of erosive mucosal injury, especially in patients with associated upper gastrointestinal disorders. Recognition of this pattern by pathologists and its communication to clinicians may aid in optimizing therapy.

Hyperplastic polyps of the esophagus and esophagogastric junction: histologic and clinicopathologic findings.

Hyperplastic polyps of the esophagus and esophagogastric junction region (EGJ) are uncommon lesions characterized by hyperplastic epithelium (foveolar-type, squamous, or both) with variable amounts of inflamed stroma. They have been reported almost exclusively in the radiologic and clinical literature as occurring predominantly in association with gastroesophageal reflux disease (GERD). Comprehensive histologic and clinicopathologic evaluation of these polyps, their association with background mucosal pathology, and their association with Barrett's esophagus has not been previously performed. We studied 30 hyperplastic polyps from 27 patients and characterized the histologic, endoscopic, and clinical features of both the polyps and the background esophagus. Hyperplastic polyps were most common in the region of the EGJ (67%), followed by the distal esophagus (30%) and mid-esophagus (3%). Most (80%) were composed of predominantly cardiac-type mucosa, predominantly squamous mucosa (17%), or an admixture (3%). Intestinal metaplasia of the polyp was present in only 7% and low-grade dysplasia in only 3%. In the majority of cases (67%) hyperplastic polyps were associated with concurrent or recent ulcers or erosive esophagitis. In most cases (48%) esophageal injury was associated with GERD, but other potential etiologies included medications, infection, anastomotic or polypectomy sites, vomiting, and photodynamic therapy. Four patients (15%) had Barrett's esophagus, three of whom had or developed dysplastic Barrett's mucosa. These results underscore the pathogenesis of esophageal/EGJ region hyperplastic polyps as a mucosal regenerative response to surrounding mucosal injury. Careful clinical history and biopsy of the nonpolypoid mucosa are essential for determining the clinicopathologic context in which the polyps have developed.

Hyperplastic polyps of the stomach: associations with histologic patterns of gastritis and gastric atrophy.

Hyperplastic polyps are common gastric lesions characterized by hyperplastic foveolae with variable amounts of inflamed stroma. Their pathogenesis is unknown, but they have been reported to occur in association with various forms of chronic gastritis, particularly autoimmune gastritis and Helicobacter pylori gastritis. Comprehensive histologic evaluation of the background mucosal pathology in patients with hyperplastic polyps has not been previously performed. We studied 160 patients with gastric hyperplastic polyps and characterized endoscopic and histologic features of the polyps (i.e., location, multiplicity, and presence of dysplasia and adenocarcinoma) and the background gastric mucosa (i.e., intestinal metaplasia, dysplasia, carcinoma, and presence and classification of gastritis). Hyperplastic polyps were most common in the antrum (60%) and were multiple in 20% of patients. Focal intestinal metaplasia of the polyp was present in 16% and dysplasia in 4% of patients. Only one patient (0.6%) had adenocarcinoma within the polyp. Evaluation of the surrounding gastric mucosa showed at least focal intestinal metaplasia in 37% of patients, adenoma or low-grade flat epithelial dysplasia in 2%, and synchronous or metachronous adenocarcinoma in 6%. Eighty-five percent of patients had inflammatory mucosal pathology, most commonly active chronic H. pylori gastritis (25%), reactive or chemical gastropathy (21%), and metaplastic atrophic gastritis of the autoimmune (12%) or environmental (8%) type. These results indicate a strong association between various forms of gastritis and the development of hyperplastic polyps and further emphasize the importance of biopsy of the nonpolypoid gastric mucosa during endoscopic examination.

Dysplasia and dysregulation of proliferation in foveolar and surface epithelia of fundic gland polyps from patients with familial adenomatous polyposis.

Fundic gland polyps (FGPs) of the stomach are regarded as hamartomatous or hyperplastic/functional polyps that occur sporadically but at increased frequency in patients with familial adenomatous polyposis syndrome (FAP). There is controversy about the histopathology of FGPs, including occurrence of dysplasia. We, therefore, studied dysplasia in 270 sporadic FGPs from 216 patients and 49 FGPs from 24 patients with FAP. We evaluated dysregulation of epithelial proliferation manifested by loss of the normal inverse topographic distribution of Ki-67 proliferation marker and the cyclin-dependent kinase inhibitor p21(WAF1/CIP1) using immunohistochemistry in 27 sporadic FGPs and in 22 FGPs from patients with FAP. Dysplasia in foveolar and surface epithelia occurred in 12 of 49 (25%) FGPs in patients with FAP but in only 3 of 270 (1%) of sporadic FGPs (p < 0.000001). Fourteen of 49 (29%) of FGPs from patients with FAP were indefinite for dysplasia, as contrasted with 8 of 270 (3%) sporadic FGPs (p < 0.00001). The normal inverse topographic distribution of Ki-67 and p21(WAF1/CIP1) was maintained in 20 of 22 (91%) of FGPs negative for dysplasia but was lost in all (8 of 8) FGPs with dysplasia and in 11 of 19 (58%) FGPs that were indefinite for dysplasia (p = 0.00001). The results indicate that dysplasia can occur in foveolar and surface epithelia of FGPs, especially in patients with FAP, and often is preceded by dysregulation of epithelial proliferation when the morphologic abnormalities are indefinite for dysplasia.

Colchicine toxicity: distinct morphologic findings in gastrointestinal biopsies.

Colchicine is an alkaloid with antimitotic ability used to treat a variety of medical conditions. Colchicine toxicity can result in multiorgan failure and death. The histopathologic features of colchicine toxicity in gastrointestinal biopsies have not been reported. Twenty-one gastrointestinal mucosal biopsies obtained from nine patients receiving oral colchicine therapy were studied. Immunohistochemical staining for Ki67 proliferation antigen was performed, and medical records of each patient were reviewed. All patients had a history of gout. Four patients with chronic renal failure also had clinical evidence of colchicine toxicity, and the other five patients did not. Distinct morphologic changes, seen as metaphase mitoses, epithelial pseudostratification, and loss of polarity, were seen in biopsy material from 4 of 4 (100%) patients with clinical colchicine toxicity. Three of these four cases (75%) also contained abundant crypt apoptotic bodies. These morphologic features were best seen in the biopsies from duodenum and gastric antrum, with relative sparing of the gastric body in the upper gastrointestinal tract. Ki67 staining demonstrated an expansion of the proliferating region in three available cases with clinical colchicine toxicity. These distinctive morphologic features were not seen in the five patients without clinical colchicine toxicity. These results indicate that colchicine toxicity can produce diagnostic morphologic features in gastrointestinal mucosal biopsies. Recognition of these features is important because colchicine toxicity can be fatal if undiagnosed clinically.

Esophageal lichen planus: case report and review of the literature.

Involvement of the esophagus by lichen planus is a rarely reported condition. The histologic features of esophageal lichen planus, which may differ from those of cutaneous disease, have only rarely been illustrated. We describe a 58-year-old woman with skin and oral lichen planus who presented with dysphagia and an esophageal stricture that were ultimately diagnosed as esophageal lichen planus. Multiple esophageal biopsies demonstrated a lichenoid, T cell-rich lymphocytic infiltrate, along with degeneration of the basal epithelium and Civatte bodies. Correct diagnosis of esophageal lichen planus is critical because of its prognostic and therapeutic distinction from other more common causes of esophagitis and stricture formation.

Colorectal cancer in ulcerative colitis: survival in patients with and without colorectal cancer symptoms.

: Patients with ulcerative colitis are at increased risk for colorectal adenocarcinoma compared with the general population. Although surveillance for colorectal malignancy and dysplasia (a premalignant lesion) has been recommended, a benefit in reducing mortality from colorectal cancer via surveillance or prophylactic colectomy is still being debated. We reviewed the outcome of 40 consecutive patients with ulcerative colitis with colorectal adenocarcinoma diagnosed between 1956 and 1991 at The Johns Hopkins Hospital. The diagnosis of ulcerative colitis and the tumor, node, metastasis (TNM) stage of colorectal cancer were obtained from clinicopathologic records. Follow-up information was complete for all patients. Patients were divided into two groups: 18 asymptomatic patients who had colorectal cancer detected by colonoscopy, biopsies for dysplasia, or barium enema, or had undergone "prophylactic" colectomy as part of a colorectal cancer-prevention strategy (asymptomatic group), whereas 22 patients did not undergo cancer-prevention testing or prophylactic surgery and had symptoms of colorectal cancer (symptomatic group). Colorectal cancer was diagnosed at a statistically significantly earlier cancer stage in the asymptomatic group [12 (67%) of 18 at stage I or II] compared with those in the symptomatic group [two (9%) of 22 at stage I or II] (Wilcoxon test, p < 0.01). Colorectal cancer 5-year survival in the asymptomatic group was 89% [confidence limit (CL), 6197%] and in the symptomatic group, 19% (CL, 6-39%). Patients with ulcerative colitis and asymptomatic colorectal cancer detected as part of a prevention strategy had malignancies that were less invasive and showed greatly increased survival compared with patients with symptomatic colorectal cancer.

Hepatoblastoma, pigmented ocular fundus lesions and jaw lesions in Gardner syndrome.

Hepatoblastoma is a rare neoplasm of infants and children only recently documented in association with hereditary adenomatous polyposis of the colon [Kingston et al., 1983]. We report four children with hepatoblastoma from four unrelated families with Gardner syndrome (GS). One child, now 19 years old, survived after a resection of a hepatoblastoma in infancy and recently was found to have GS. He has an associated odontoma and pigmented ocular fundus lesions, both of which have been shown to be clinical markers of GS. Many individuals in these four GS families, both affected and at risk, have osteomatous jaw lesions and pigmented ocular fundus lesions. A search for colonic polyps should be made in families of infants and children with hepatoblastoma. If the child survives, he or she should be monitored for the later appearance of colonic polyps. The finding of jaw lesions and/or pigmented ocular fundus lesions in relatives at risk are indications of the possible presence of the GS gene.

Immunoperoxidase stains of ganglion cells and abnormal mucosal nerve proliferations in Hirschsprung's disease.

Hirschsprung's disease is congenital aganglionosis of the distal colon. The affected bowel shows an abnormal proliferation of mucosal nerve fibers by acetylcholinesterase stains. We retrospectively reviewed biopsy specimens from patients with suspected and proven Hirschsprung's disease, performed immunoperoxidase stains for S-100 protein and neuron-specific enolase (NSE), and compared these results to routine histologic findings and acetylcholinesterase stains. Ganglion cells were demonstrated by immunoperoxidase in 63 of 69 specimens containing ganglion cells and in 1 specimen interpreted as aganglionic by hematoxylin-eosin staining. Increased numbers of nerve fibers in the muscularis mucosae and deep lamina propria by S-100 staining were detected in 8 of 8 specimens diagnostic for Hirschsprung's disease by hematoxylin-eosin and acetylcholinesterase stains and in 1 specimen diagnostic for colonic neuronal dysplasia (a disorder related to Hirschsprung's disease). Whereas 45 of 67 specimens from unaffected bowel showed a normal number and distribution of nerve fibers by S-100 staining, in 22 the pattern resembled that of Hirschsprung's disease. Specimens from affected colon also showed hypertrophied submucosal nerve trunks by S-100 stain (average nerve trunk thickness, 29.8 micron in affected bowel, 16.1 micron in unaffected segments--p less than 0.03). We conclude that NSE and S-100 stains are of value in demonstrating ganglion cells in suspected cases of Hirschsprung's disease and colonic neuronal dysplasia. The acetylcholinesterase stain is preferred over S-100 stain for detecting mucosal nerve proliferations in affected bowel. Submucosal nerve trunk thickness, although significantly different in affected and unaffected colon, is not of diagnostic value because of the wide variation in the measurements in the two groups.

Pitfalls in the diagnosis of collagenous colitis: experience with 75 cases from a registry of collagenous colitis at the Johns Hopkins Hospital.

Collagenous colitis is a relatively rare disorder presenting mainly in middle-aged women as watery diarrhea. Endoscopic and radiographic studies of the colon are usually normal, and diagnosis must be made by biopsy. The characteristic biopsy findings are a combination of increased mucosal inflammation (collagenous colitis) as well as subepithelial collagenous thickening. The mucosal inflammatory changes include increased lamina propria plasma cells, prominent intraepithelial lymphocytes, and in some cases, numerous eosinophils. The collagenous thickening has qualitative as well as quantitative differences from normal, and may be highlighted by Masson trichrome stains. Simply quantitating the thickness of a subepithelial collagen layer is neither adequate nor necessary for the diagnosis of collagenous colitis. Major problems in diagnosing collagenous colitis arise from focusing solely on the subepithelial region without attention to inflammatory changes. For example, tangential sectioning of normal colon results in an artifactually thickened basement membrane, and such cases have been wrongly interpreted as collagenous colitis. If biopsies lack the characteristic inflammatory pattern, a tangentially cut thick basement membrane should be ignored. The key to correct diagnosis of collagenous colitis is analyzing the summation of various inflammatory changes plus subepithelial collagenization, rather than focusing on any single feature in isolation.

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.

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.

Prominent mononuclear cell infiltrate is characteristic of herpes esophagitis.

Diagnosis of herpes esophagitis is often difficult since the characteristic nuclear inclusions and/or multinucleate giant cells of herpes virus infection may be absent in endoscopic biopsy specimens. We have noted aggregates of large mononuclear cells with convoluted nuclei adjacent to infected epithelium in the exudates of herpetic esophagitis, and postulate that this is a characteristic inflammatory response to the virus. To test this hypothesis, we reviewed biopsies from 22 cases of ulcerative herpetic esophagitis and from 44 control cases of nonherpetic esophageal ulcers (including nine cases of candidal and five cases of bacterial esophagitis) that contained a quantifiable amount of exudate. The estimated percentage of mononuclear cells present in the specimens was ranked independently by two reviewers using coded photomicrographs of exudate. Wilcoxon's rank sum analysis demonstrated significant correlation between presence of herpes and increased mononuclear cells (P less than .0001). Only one of the 22 herpes cases did not show a prominent mononuclear cell infiltrate. Immunoperoxidase studies performed on Hollande-Bouin's-fixed paraffin-embedded material from 11 herpes cases showed strong staining of the mononuclear cells for KP-1 (CD68), indicating that the majority of these cells are macrophages. These findings suggest strongly that aggregates of macrophages are characteristic of the inflammatory response in ulcerative herpetic esophagitis. The presence of these mononuclear cells in a biopsy specimen that initially does not show herpetic inclusions warrants additional studies to rule out herpes virus infection.

Cryptosporidiosis in an immunosuppressed renal-transplant recipient with IgA deficiency.

Cryptosporidia are sporozoan parasites that infect epithelial cells of the gastrointestinal tract. Infection with cryptosporidia has been found most commonly in a variety of animal species and only rarely in man. The authors report a case of an immunosuppressed renal-transplant recipient with IgA deficiency who experienced diarrhea and fever and was found to have cryptosporidia in a jejunal biopsy specimen and in air-dried smears of the specimen. By electron microscopy, trophozoite, schizont, and macrogamete forms were identified, and these forms ahd morphologic features similar to those of cryptosporidia previously found in guinea pigs. Treatment of the cryptosporidial infection in this case was with trisulfapyrimidines. The efficacy of this treatment could not be evaluated because of complications.

Pseudosarcomatous changes in inflammatory pseudopolyps of the colon.

The occurrence of pseudomalignant changes in biopsy specimens from two patients with ulcerative colitis and pseudopolyposis is described. One lesion was characterized by the proliferation of large ganglion cell-like cells, similar to those observed in proliferative fasciitis. Ultrastructural and immunohistochemical findings supported a fibroblastic origin. Biopsy specimens of an inflammatory pseudopolyp from the second patient showed proliferation of oval to spindle cells that were initially interpreted as a possible neoplasm. The site of origin and reactive nature of this lesion became apparent on a subsequent polypectomy specimen. Attention is called to the occurrence of pseudosarcomatous changes in inflammatory pseudopolyps of the gastrointestinal tract that may lead to an erroneous diagnosis of malignancy.