Search

1p36 deletion syndrome is the most common terminal deletion syndrome, manifesting clinically as abnormal facies and developmental delay with frequent cardiac, skeletal, urogenital, and renal abnormalities. Limited autopsy case reports describe the neuropathology of 1p36 deletion syndrome. The most extensive single case report described a spectrum of abnormalities, mostly related to abnormal neuronal migration. We report the largest published series of 1p36 autopsy cases, with an emphasis on neuropathologic findings. Our series consists of 3 patients: 2 infants (5-hours old and 23-days old) and 1 older child (11 years). Our patients showed abnormal cortical gyration together with a spectrum of neuronal migration abnormalities, including heterotopias and hippocampal abnormalities, as well as cerebellar hypoplasia. Our findings thus support the role of neuronal migration defects in the pathogenesis of cognitive defects in 1p36 deletion syndrome and broaden the reported neuropathologic spectrum of this common syndrome.

Objectives While flow cytometry is routinely used in the diagnostic work-up of hematolymphoid malignancies, its role in identifying non-hematolymphoid neoplasms is controversial. While a diagnosis of “non-hematolymphoid process” may be suggested by flow cytometry, typically, CD45-negative entities are not further characterized by their immunophenotypic profile. Some markers, such as CD56, have been well documented in non-hematolymphoid malignancies, such as high-grade neuroendocrine carcinomas (Stacchini, et al, 2018; Bryson et al, 2002). Other cell surface markers that are routinely studied with flow cytometry panels, such as CD200, are less well-described in the literature with regards to their presence/absence in non-hematolymphoid processes. We examined all flow cytometry cases from our institution over a 5-year period to identify trends in the immunophenotypes of non-hematolymphoid malignancies that were known to be CD45-negative and CD56-positive by flow cytometry. Methods We examined 3634 flow cytometry cases (2015-2020) and identified non-hematolymphoid cases based upon lack of CD45 expression. After excluding multiple myeloma cases from the CD45-negative entities, we were left with 19 CD45-negative cases. Chart review of these cases confirmed them as non-hematolymphoid by concurrent surgical pathology/cytopathology studies. Of these 19 cases, 2 were excluded because CD56 was not evaluated. Results Of the 17 CD45-negative/CD56-positive cases, 16 showed CD200 positivity (94%). Of these CD200-positive cases, 10 were ultimately diagnosed as small cell carcinoma (59%), 1 was diagnosed as Merkel cell carcinoma (6%), 1 was diagnosed as melanoma (6%), 1 was diagnosed as poorly-differentiated carcinoma (6%), 1 was diagnosed as Ewing-like sarcoma (6%), and 2 were unclassified further (12%). The single CD200-negative case was diagnosed as poorly-differentiated acinar cell carcinoma (6%). All cases of small cell carcinoma that were evaluated by flow cytometry showed expression of CD200 and CD56. Conclusions Our findings suggest that in CD45-negative/CD56-positive non-hematolymphoid malignancies, particularly small cell carcinoma, CD200 is frequently positive. CD200 was also found to be positive in rare cases of other non-hematolymphoid malignancies within the differential diagnosis of small round blue cell tumors. These findings indicate that CD200 may be a useful marker in suggesting the possibility of small cell carcinoma in non-hematolymphoid specimens that are evaluated by flow cytometry.

Anion gap is a value calculated by determining the difference between major plasma cations (sodium, sometimes additionally potassium) and anions (namely bicarbonate and chloride), with “normal” levels falling somewhere between 8 and 16 mEq/L. Elevations in anion gap are classically described in a variety of different clinical disease states, including but not limited to uremia, ketoacidoses, lactic acidosis, and a number of drug toxicities. Comparatively little is understood about the etiology of low and negative (

Objectives Composite frozen section turnaround time has limited value, precluding assessment of certain processes: slide preparation (technical) and diagnosis (interpretation). We examined whether measuring these elements could identify delays, hypothesizing that longer times were related to (1) inefficient technical processes and (2) case-specific diagnostic challenges. Methods Technical and interpretive times were determined for 1,992 specimens submitted for frozen section in 2017; the data were sorted by surgical specialty. Mean and quartile times were determined for each category with all specimens assessed equally, including those with multiple frozen section blocks. Results Technical times were significantly longer than interpretive times. Specialty grouping facilitated trend identification and enabled assessment of technical and interpretation challenges. We identified technical issues with certain gross specimens involving overdissection and interpretation delays for specific neoplasms and margins. Conclusions Measuring technical and interpretative times and subcategorizing by specialty has aided the assessment of frozen section processing in our laboratory, enabling case isolation for process improvement.