Mundell, William

Abstract Background Thyroid function testing is a common laboratory service that can be optimized by implementing evidence-based algorithms. The thyroid function cascade testing approach at Mayo Clinic Labs is utilized to effectively evaluate and monitor functional thyroid status. The cascade begins with thyroid-stimulating hormone (TSH) as a screening marker. When TSH levels are normal, no additional testing is necessary. When the TSH result is abnormal, appropriate follow-up free T4, total T3, and/or TPO testing will automatically be performed. Providers at our institution can order thyroid function testing with this cascade testing approach or as standalone individual orderable tests. Initial data analysis showed patterns of TSH ordered concurrently with free T4, total T3, and/or anti-TPO. Further analysis revealed that a high number of concurrently ordered tests would not have been necessary had the algorithmic approach been followed. This opportunity for improvement led to the thyroid function testing initiative to direct providers to order the cascade test rather than individual thyroid tests, thereby reducing concurrent and unnecessary testing to improve patient care. Methods The initiative involved creating a new Epic order panel directing providers to order the cascade rather than the individual orderable tests. This intervention is a soft stop that allows providers to proceed by ordering individual tests if desired. We evaluated the impact of the initiative on test utilization, cost savings, and quality indicators using pre- and post-intervention data from all Mayo Clinic sites over a 9-month period. We compared the monthly volumes of concurrent and unnecessary orders of Free T4, Total T3, and TPO before and after the intervention. Concurrent orders were defined as tests collected from the same patient on the same date and time as TSH tests. Unnecessary orders were defined as tests that were outside the reflex range according to the thyroid function ordering algorithm. Cost savings were calculated based on the 2024 CMS reimbursement rates for the associated test CPT® codes. We also monitored and addressed feedback and requests from providers and laboratory staff throughout the initiative. Results The intervention resulted in a 20% average monthly reduction in concurrent orders and an 18% average monthly reduction in unnecessary orders of free T4, total T3, and anti-TPO tests. Estimated savings based on 2024 CMS reimbursement rates are $5,000 monthly and nearly $60,000 annually. Thyroid testing quality was also improved by aligning with clinical guidelines, reducing over-testing, and minimizing the risk of misdiagnosis. Conclusion The thyroid function testing initiative was a successful laboratory stewardship project that reduced redundant testing, improved patient care, and reduced costs. The initiative demonstrated the feasibility and effectiveness of using evidence-based reflex algorithms to optimize laboratory testing. The lessons learned include assessing all tests related to the disease condition to mitigate potential unintended increases in test usage and accounting for patient groups that are not covered by the intended algorithm*s target population. Future directions include expanding the cascade approach to other areas of laboratory medicine, evaluating the long-term outcomes of the initiative, and engaging with providers to ensure the adoption of the initiative.

Diffuse large B-cell lymphoma (DLBCL) is the most prevalent and aggressive subtype of non-Hodgkin lymphoma comprising 30% to 40% of cases. While DLBCL frequently arises in the lymph nodes, up to 40% of cases originate in extranodal tissues. Primary splenic DLBCL is extremely rare comprising only ~1% of DLBCL cases and can be complicated by rare entities including gastrosplenic fistula (GSF). In contrast to DLBCL, polycythemia vera (PV) is a myeloproliferative malignancy. Polycythemia vera can transform into other hematologic malignancies including post-polycythemia myelofibrosis, but associations with DLBCL are uncommon. We present the first case of PV with concomitant primary splenic DLBCL complicated by GSF. While the majority of splenic lesions are benign, they have a broad differential diagnosis including malignant etiologies. Cystic or solid morphology, the number of lesions, and vascularity on imaging heavily guide further management. Due to concern for imminent massive upper gastrointestinal bleeding in the setting of GSF, our patient was diagnosed and managed with prompt splenectomy and gastrectomy. Percutaneous splenic biopsy is also a safe and effective diagnostic modality, but was deferred in our case given increased bleeding risk with PV. In conclusion, primary splenic lymphoma should be in the differential for a splenic mass regardless of whether the patient has a prior hematologic malignancy, and management should be prompt especially if complicated by a GSF.

Diverticular disease is a major cause of hospitalizations, especially in the elderly. Although diverticulosis and its complications predominately affect the colon, the formation of diverticula in the small intestine, most commonly in the duodenum, is well characterized in the literature. Although small bowel diverticula are typically asymptomatic, and diagnosed incidentally, a complication of periampullary duodenal diverticulum is Lemmel syndrome. Lemmel syndrome is an extremely rare condition whereby periampullary duodenal diverticula, most commonly without diverticulitis, leads to obstruction of the common bile duct due to mass effect and associated complications including acute cholangitis and pancreatitis. Here, we present the first case, to our knowledge, of periampullary duodenal diverticulitis complicated by Lemmel syndrome with concomitant colonic diverticulitis with colovesical fistula. Our case and literature review emphasizes that Lemmel syndrome can present with or without suggestions of obstructive jaundice and can most often be managed conservatively if caught early, except in the setting of emergent complications.