Crohn's-like clinical and pathological manifestations of giant inflammatory polyposis in IBD: a potential diagnostic pitfall.

BACKGROUND & AIMS: Giant inflammatory polyposis (GIP), characterized by mass-like agglomerations of inflammatory polyps, is a rare complication of inflammatory bowel disease (IBD). We reviewed a series of cases of GIP to determine its diagnostic impact on the clinical and pathologic distinction between ulcerative colitis (UC) and colonic Crohn's disease (CD). METHODS: All colons with GIP resected over a 13-year period were identified prospectively and the corresponding clinical and pathologic records were reviewed. RESULTS: Twelve cases of GIP were identified, accounting for 0.8% of colectomies for IBD during the same time interval. Preoperatively, 6 (50%) patients were diagnosed with UC, 2 (17%) with CD and 4 (33%) with indeterminate colitis (IC). Postoperatively, 6 of the diagnoses (50%) were revised based on strict histopathologic criteria: all 4 diagnoses of IC to UC, one diagnosis of CD to UC, and one diagnosis of UC to CD, for a total of 10 diagnoses of UC (83%) and two of CD (17%). Significantly, 7 of 10 cases with postoperative diagnoses of UC (70%) had Crohn's-like transmural inflammation exclusively within the polyposis segments attributed to fecal entrapment and stasis and accounting for the Crohn's-like clinical complications in these cases. CONCLUSIONS: This case series of GIP, the largest reported from a single center, highlights the high rate of Crohn's-like clinical and pathological manifestations of GIP and their potential to confound the accurate classification of patients with IBD. A diagnosis of UC should not be amended to CD based on the findings of the polyposis segment alone.

'Mohs surgery of the prostate': the utility of in situ frozen section analysis during robotic prostatectomy.

OBJECTIVE • To evaluate a novel technique to lower positive surgical margin rates while preserving as much of the neurovascular bundles as possible during nerve-sparing robotic prostatectomy. MATERIALS AND METHODS • In situ intraoperative frozen section (IFS) was performed during robotic-assisted laparoscopic prostatectomy (RALP) when there was macroscopic concern for a positive margin or residual prostate tissue. • When IFS was positive, additional sections were taken from the same area until the IFS was negative, similar to the procedure of Mohs micrographic surgery. • Positive surgical margin and biochemical recurrence rates were compared between the patients who underwent IFS and those who did not. RESULTS • Of 970 patients consecutively undergoing RALP at a single institution, IFS was performed on 177 (18%). • Eleven patients (6%) had IFS positive for carcinoma, whereas another 25 (14%) had benign prostatic tissue in the IFS specimen. • IFS and non-IFS patients had similar pathological and nerve-sparing characteristics. • The IFS group had significantly lower rates of positive surgical margins, 7% vs 18% (P = 0.001) but similar rates of biochemical recurrence (5%) at a median follow-up of 11 months. CONCLUSIONS • In situ IFS is an effective way of reducing positive margins during RALP. • Twenty percent of patients who underwent IFS, representing 4% of the overall RALP population, had either malignant or benign prostate tissue removed from their prostatic fossa. • Although a reduction of biochemical recurrence was not demonstrated, the follow-up is short and a difference may become apparent as the data mature.

Duplication and triplication of der(21)t(8;21)(q22;q22) in acute myeloid leukemia.

We report on two patients with complicons resulting in duplication der(21)t(8;21)(q22;q22), triplication in the form of isochromosome of der(21)t(8;21), and four copies of ETO-AML1 fusion. Duplication of der(21) was present at diagnosis as a minor cell population in one patient, while the presence of isoderivative (21)t(8;21) characterized the relapse cells of the second patient. Due to the rarity of these cases, literature search of other reported cases of complicons may be taken as evidence that duplication and triplication of ETO-AML1 may be a poor prognostic indicator, regardless of whether it is present at diagnosis or relapse.