A case report of mesenteric heterotopic ossification: Histopathologic and genetic findings.

Mesenteric heterotopic ossification (MHO) is very rare and occurs in mid- to late-adulthood, usually in the context of prior abdominal surgery. The mechanisms of MHO are unknown. Here we describe the case of a 72-year-old man with MHO. Standard histological staining revealed that MHO occurred through an endochondral process. By comparison to known mutations in genetic conditions of HO such as fibrodysplasia ossificans progressiva (FOP) and progressive osseous heteroplasia (POH), DNA sequencing analysis demonstrated the presence of a commonly occurring heterozygous synonymous polymorphism (c.690G>A; E230E) in the causative gene for FOP (ACVR1/ALK2). However, no frameshift, missense, or nonsense mutations in ACVR1, or in the causative gene for POH (GNAS), were found. Although genetic predisposition may play a role in MHO, our data suggest that mutations which occur in known hereditary conditions of HO are not the primary cause.

Imprint cytopathology of core needle biopsies: a "first responder" role for cytotechnologists.

INTRODUCTION: Imprint cytopathology (IC) of image-guided core needle biopsies (CNBs) is used to ensure adequate sampling. In our institution, cytotechnologists (CyTs) are the "first responders" for on-site adequacy assessment (OSAA) of image-guided CNBs. We report our experience with this expanded and relatively unexplored role for CyT. MATERIALS AND METHODS: We reviewed all image-guided CNBs performed over a 12-month period that required OSAA. OSAA was provided primarily by CyT. Interpretation between all IC specimens and tissue diagnoses (concordance) and between adequate IC specimens and tissue diagnoses (accuracy) were analyzed. Performance was compared using the Fisher exact test. We retrospectively reviewed discrepant cases to deduce the reasons for discordance. RESULTS: We evaluated 255 CNBs: 179 computed tomography-guided, 74 ultrasonography-guided, 2 endoscopy-guided. Lung (39%) followed by liver (16%) and lymph node (11%) were the most frequent sites of OSAA IC. Overall adequacy and accuracy rates were 80.8% and 87.9%, respectively, with a concordance rate of 81.2%. The performance for CyT alone, CyT/cytopathology fellow, and CyT/cytopathologist were comparable (P > 0.05). Review of discordant cases showed agreement with 91% of OSAA IC cases originally interpreted as inadequate, but with only 19% interpreted as adequate. CONCLUSIONS: OSAA IC of CNBs expands the CyT's role in an effort to ensure adequate sampling. CyT performance was high in recognition of adequate versus inadequate IC slides when compared with the tissue. Reasons for discrepancy included sampling error and overinterpretation of atypia as being sufficient evidence of adequacy. Organ-specific cytologic criteria to assess adequacy are required to reduce interpretation error.