Inaccurate and incomplete diagnoses of malignant polyps as a cause of pathologic tumor stage T0 colectomy.

The purpose of this study was to retrospectively review cases of pathologic tumor stage T0 (pT0) colectomy for colon cancer to determine whether any cases could be attributed to inaccurate (false-positive) or incomplete biopsy diagnoses. We conducted a search of our laboratory archives for all biopsy diagnoses of invasive colonic adenocarcinoma over a period of 11 years. Rectal carcinomas and those treated neoadjuvantly were excluded. The subset of interest consisted of those biopsies that were followed up by a colectomy specimen with no invasive malignancy. There were 762 biopsy diagnoses of invasive colon cancer, of which 564 (74.0%) had subsequent colectomy. Thirty-two resection cases (5.7%) were classified as pT0 on resection. After review, 2 gastrointestinal pathologists determined that 4 (0.7%) of the original biopsies represented false-positive diagnoses of invasive malignancy. They agreed that 24 cases represented malignant polyps containing invasive adenocarcinoma and disagreed on the presence of invasion in 4 cases. Less than half (15/32, 46.9%) of reviewed cases had included all parameters required, when diagnosing early colon cancer in a polypectomy. We are not aware of any other published quality assurance studies looking specifically at false diagnosis of invasion as a cause of pT0 colon cancer resections. In this retrospective review, most biopsy diagnoses were accurate. However, false-positive biopsy diagnoses of colon cancer do occur and may lead to pT0 colectomy.

Dysplasia Epiphysealis Hemimelica/Trevor Disease: Report of a Lesion Solely Involving the Lunate Bone: A Case Report.

CASE: We describe the case of a dysplasia epiphysealis hemimelica (DEH) lesion affecting uniquely the lunate bone in a 16-year-old boy causing pain, stiffness, and decreased range of motion. Surgical excision was performed, leading to resolution of primary symptoms with residual limitations in terminal wrist extension. CONCLUSIONS: From our review of the literature, we believe this case to be the first report of a DEH lesion affecting solely the lunate bone. Although conservative and surgical management have both been described with DEH cases, we report a positive outcome following the excision of a symptomatic lesion.

A case of clear cell meningioma with tyrosine-rich crystals.

We present a case of clear cell meningioma with unusual clinical and pathologic features. The patient was a 54-year-old man who underwent laminectomy and durotomy for an intradural tumor in the lumbar spinal canal. Sections showed a predominance of dense collagenous tissue with irregularly shaped and irregularly sized magenta-colored extracellular deposits. On electron microscopy, these deposits were osmiophilic and "petaloid." The final diagnosis of clear cell meningioma rested on relatively inconspicuous intervening nests of glycogen-containing clear cells that were positive for epithelial membrane antigen. The unusual extracellular deposits seen in this case have previously been characterized as tyrosine-rich crystals of the type most commonly seen in salivary gland tumors. Recognition of this tumor as a clear cell meningioma, despite misleading clinical features and initially challenging histologic findings, is not only a matter of diagnostic accuracy but also imparts important prognostic information.