Precolectomy Therapy Does Not Alter Histologic Findings Distribution in Resected Colon in Pediatric Ulcerative Colitis.

OBJECTIVES: Medically intractable pediatric ulcerative colitis can lead to colectomy after which patients commonly receive an ileoanal pouch. Postoperative complications are more common in patients with Crohn disease, a diagnosis that may be rendered after the colectomy specimen is examined. Because most children are likely to be exposed to medications before colectomy, we sought to examine whether such exposure influences the distribution of the inflammation within the resected colon and therefore potentially raise questions about the diagnosis accuracy. METHODS: We conducted a retrospective cohort study of 32 pediatric ulcerative colitis cases undergoing colectomy from 2007 to 2014 for clinical data and precolectomy treatment history. The resected colon histology was reviewed independently by 2 blinded pathologists. The acute/active inflammation was scored using the modified Riley score for 3 colonic segments (proximal, transverse, and distal colon) for each patient. Linear mixed-effects models were used to evaluate possible association between acute/active inflammation scores at various sites and medication use. RESULTS: Twelve cases (38%) showed decreasing acute inflammation score distally to proximally, 8 (25%) had increasing scores, and 12 cases showed no change. Patients were most commonly exposed to corticosteroids, followed by anti-tumor necrosis factor antibodies. There was no statistically or clinically significant change in the histologic scores across the colonic segments of the resected colon in association with exposure to any specific medication or combination of medications, sex, age at diagnosis and surgery, or duration of disease. CONCLUSIONS: Precolectomy therapy does not seem to influence the distribution of inflammation within the resected colon.

Flat Urothelial Lesions With Atypia: Interobserver Concordance and Added Value of Immunohistochemical Profiling.

BACKGROUND: Distinguishing urothelial carcinoma in situ (CIS) from other flat lesions of the urinary bladder with cytologic atypia is critically important for the management of patients with bladder neoplasia. However, there is high interpathologist variability in making these distinctions. OBJECTIVE: The aim of this study is to assess interobserver agreement between general and specialized genitourinary pathologists, and to compare these diagnoses with those rendered after an immunohistochemical panel is performed. We hypothesized that addition of a set of immunohistochemical stains would reduce the number of cases classified within intermediate categories of atypia of uncertain significance and low-grade dysplasia. DESIGN: Two genitourinary pathologists independently assessed haematoxylin and eosin (H&E)-stained sections of 127 bladder biopsies from each of the 4 International Society of Urological Pathology/World Health Organization categories of flat lesions diagnosed by general pathologists. A subset of biopsies from 49 patients was reassessed after staining with a 3-antibody panel (CD44, CK20, and p53) and the results were correlated with patient follow-up. RESULTS: Based on these immunohistochemistry (IHC) stains, 26 cases (53.1%) were recategorized. Of most clinical importance, 5 of 27 cases (18.5%) originally diagnosed as either atypia of uncertain significance or low-grade dysplasia were recategorized as CIS, and recurrent disease was identified on subsequent biopsies. None of the 10 cases diagnosed as CIS based on H&E stains were recategorized. CONCLUSIONS: This triad of IHC stains can improve the precision of pathologic diagnosis of histologically atypical urothelial lesions of flat bladder mucosa. We recommend that pathologists apply this set of IHC stains to such lesions they find problematic based on H&E stains.

Massive Gastric Juvenile Polyposis: A Clinicopathologic Study Using SMAD4 Immunohistochemistry.

OBJECTIVES: Juvenile polyps involving the stomach are uncommon. Massive gastric juvenile polyposis is even rarer. METHODS: We describe the clinicopathologic features of nine cases of massive gastric juvenile polyposis. RESULTS: All patients had anemia; four had hypoalbuminemia. The polyps were composed predominantly of dilated crypts lined by columnar epithelium and abundant edematous stroma with mixed inflammatory infiltrates. One patient had a poorly differentiated adenocarcinoma, arising in juvenile polyp-associated intraepithelial neoplasia. A second patient had a well-differentiated intramucosal adenocarcinoma arising in a juvenile polyp with high-grade dysplasia. Three of our cases had polyposis restricted to the stomach. Six (66.6%) had loss of SMAD4 immunoreactivity, making them subject to severe bleeding and hypoproteinemia, as well as developing severe dysplasia or adenocarcinoma. CONCLUSIONS: SMAD4 immunohistochemstry is a helpful ancillary diagnostic test in cases of suspected juvenile polyposis syndrome involving the stomach.

Lymphangiomatous Lesions of the Gastrointestinal Tract: A Clinicopathologic Study and Comparison Between Adults and Children.

OBJECTIVES: Lymphangiomatous lesions involving the gastrointestinal (GI) tract remain incompletely characterized, and their clinical and histopathologic features have not been systematically evaluated. The distinction between a primary lymphatic malformation (lymphangioma) and a dilation of existing lymphatics (lymphangiectasia) is of clinical significance, since lymphangiectasia may occur in the setting of lymphatic obstruction due to an unsampled malignancy. We describe clinical and morphologic features of lymphangiomas of the GI tract in adult and pediatric populations and contrast them with lymphangiectasia. METHODS: We performed a retrospective review of adult and pediatric lymphangiomas and lymphangiectasia involving the GI tract. RESULTS: Thirty-six cases of lymphangioma and lymphangiectasia were retrieved, and clinical presentation and histologic features were compared. Lymphangiomas had distinct clinical presentations in adults and children, with adult lesions being more frequently asymptomatic and more frequently involving the superficial mucosal layers of the GI tract. Microscopically, lymphangiomas mostly consisted of confluent dilated spaces with a smooth muscle component. This appearance differed from lymphangiectasia, which lacked a complete distinct endothelial or smooth muscle lining and diffusely involved the mucosa and submucosa. CONCLUSIONS: Morphologic features of GI tract lymphangiomas can be reliably distinguished from lymphangiectasia by clinical and pathologic characteristics.

Beta-human chorionic gonadotropin expression in recurrent and metastatic giant cell tumors of bone: a potential mimicker of germ cell tumor.

Giant cell tumors of bone (GCTs) are generally benign, locally aggressive neoplasms that rarely metastasize. The beta subunit of human chorionic gonadotropin (beta-hCG) is expressed in syncytiotrophoblasts and several nongynecologic neoplasms but has not been described in GCT. At our institution, we observed cases of elevated beta-hCG in patients with GCT leading to diagnostic difficulty and in one case, concern for metastatic choriocarcinoma. This study aims to determine the frequency of beta-hCG expression in GCT and any relationship to clinical aggressiveness. We evaluated tissue expression of beta-hCG by immunohistochemistry with 58% of cases staining for beta-hCG. Additionally, 2 of 11 patients with available serum and/or urine beta-hCG measurements demonstrated elevated beta-hCG due to tumor. It is important to be aware of beta-hCG expression by GCT and the potential for elevated urine and serum beta-hCG levels in patients with GCT so as to avoid misdiagnosis of pregnancy or gestational trophoblastic disease.