Abdominopelvic CT in COVID-19 patients with abdominal complaints including both waves and controls: reader agreement and overcalls after consensus review.

BACKGROUND: Since many COVID-19 publications lack consensus reviews or controls, interpretive accuracy is unclear; abdominal processes unique or infrequent during the pandemic remain unknown. The incidence and nature of CT findings accounting for abdominal complaints in COVID patients, reader agreement and overcalling will be determined. METHODS: A retrospective study was performed on COVID patients with abdominal complaints from 3/15/2020-5/31/2020 and 11/1/2020-4/15/2021 including matched controls. Reviewers blinded to initial reads interpreted abdominopelvic CT exams, with discordant cases resolved in consensus. Reader agreement was measured by Cohen's Kappa, differences between cohorts by permutation tests and factors affecting false positive/negative rates by Fisher's Exact Test and logistic regression. RESULTS: 116 first wave (average age 65 years [±15.3], 63 [54%] women) and 194 second wave COVID cases (average age 64 years [±16.3], 103 [53%] women) including 116 wave 1 and 194 wave 2 prepandemic controls were included. Concordance was lower among COVID cases than controls (Cohen's Kappa of 0.58 vs. 0.82 [p ≤ 0.001]) and among wave 1 than wave 2 cases (Cohen's Kappa of 0.45 vs. 0.66 [p = 0.052]). With true positives defined as consensus between the initial reader and study reader, false positive rates were higher among COVID cases than controls (OR = 0.42, p = 0.003) and for initial than study reader (OR = 0.36, p ≤ 0.001), but lower in wave 2 than 1 (OR = 0.5, p = 0.028). CONCLUSION: Greater reader disagreement occurred during COVID than prepandemic with no reader bias as both initial and study readers called more false positives among COVID cases than controls. More overcalling occurred during COVID with colitis and cystitis most common.

Cardiovascular Involvement of a CD138-Negative Anaplastic Myeloma: A Diagnostic Dilemma.

Anaplastic myeloma (AM) is an extremely rare and aggressive histological variant of myeloma. It is characterized by extramedullary presentation in the young and has a poor prognosis. It can be a diagnostic challenge when myeloma is not suspected and even more when the immunophenotype is unexpected. We present a rare presentation of anaplastic myeloma with cardiovascular involvement. Though the patient did not have the typical clinical features of myeloma, except lytic lesion in the femur, the cardiac biopsy showed sheets of anaplastic cells, and some with multinucleation. There were also some areas with a more plasmacytoid appearance. The initial immunohistochemical panel was negative for CD3, CD20, CD138, AE1/3, and kappa. It was positive for lambda. This led to an extended panel which showed positivity for CD79a and MUM1 and negative for LMP-1, HHV-8, CD43, CD117, CD56, and CD30. Even the flow cytometry on the bone marrow showed a small population of atypical cells positive for CD38 and negative for CD138 with lambda restriction. This is an unusual case of anaplastic myeloma with cardiovascular involvement and CD138 negativity. This case highlights the need to add a panel of plasma cell markers when myeloma is suspected, and it is pertinent to read flow cytometry with caution to avoid missing atypical plasma cells which maybe CD38+/CD138-.

Re-Identification Risk in HIPAA De-Identified Datasets: The MVA Attack.

We present a re-identification attack that uses indirect (non-HIPAA) identifiers to target a vulnerable subset of records de-identified to the HIPAA Safe Harbor standard, those involving motor vehicle accidents (MVAs). Documentation of an MVA in a patient note creates a significant risk to patient privacy through the MVA re-identification attack, with a relative risk of 537 compared to the general population. Patients in a significant MVA resulting in either permanent injury, hospitalization or death (for any victim) should have the accident location information omitted due to the significant risk of re-identification of HIPAA de-identified data. Clinicians should also consider omitting location information for any MVA, as it significantly increases the risk of re-identification.