Immune checkpoint inhibitor-associated myocarditis : Case reports and a review of the literature

Immune checkpoint inhibitors (ICIs) are increasingly recognised to effectuate long-lasting therapeutic responses in solid tumours. However, ICI therapy can also result in various immune-related adverse events, such as ICI-associated myocarditis, a rare but serious complication. The clinical spectrum is wide and includes asymptomatic patients and patients with fulminant heart failure, making it challenging to diagnose this condition. Furthermore, the optimal diagnostic algorithm and treatment of ICI-associated myocarditis is unknown. In this review, we describe two cases on both ends of the spectrum and discuss the challenges in recognising, diagnosing and treating ICI-associated myocarditis.

SDH Subunit Mutation Status in Saliva: Genetic Testing in Patients with Pheochromocytoma

Germline mutations occur in up to 30-40% of pheochromocytoma/paraganglioma, with mutations in the succinate dehydrogenase (SDH) subunits B (SDHB) and D (SDHD) being the most common. Blood samples are favored for obtaining high quality DNA, however, leukocytes can also be obtained by collecting saliva. The aim of this study was to determine whether SDHB and SDHD gene mutations in patients with pheochromocytoma/paraganglioma could be determined using a salivary sample. Paired blood and salivary samples were collected from 30 patients: 9 SDHB mutation positive, 13 with a SDHD mutation, and 8 without any SDHx mutations. The Oragene DISCOVER kit was used to collect and extract DNA from saliva. Blood DNA was extracted from EDTA blood samples. The DNA purification and concentration were measured by spectrophotometry. The 8 exons of SDHB and the 4 exons of SDHD were amplified and sequenced by PCR-based bidirectional Sanger sequencing. Total DNA yields from blood DNA were similar to those obtained from saliva DNA [mean (±SD) saliva vs. blood DNA concentration 514.6 (±580.8) ng/µl vs. 360.9 (±262.7) ng/µl; p=0.2)]. The purity of the saliva DNA samples was lower than that of blood [mean OD260/OD280 ratio 1.78 (±0.13) vs. 1.87 (±0.04); p=0.001, respectively], indicating more protein contamination in the saliva-extracted DNA. This study shows that salivary DNA collected from patients with pheochromocytoma/paraganglioma is a good alternative for extraction of genomic DNA for its high DNA concentration and acceptable purity and can be used as an alternative to blood derived DNA in screening for SDHB and SDHD mutations.

Intestinal pseudo-obstruction as a complication of paragangliomas: case report and literature review

Intestinal pseudo-obstruction is a rare and relatively unknown complication of phaeochromocytoma÷ paraganglioma (PCC÷PGL). Its pathophysiology can be explained by the hypersecretion of catecholamines, which may reduce the peristaltic activity of the gastrointestinal tract. Clinically, this can result in chronic constipation, intestinal pseudo-obstruction or even intestinal perforation. We conducted a comprehensive literature search and retrieved 34 cases of pseudo-obstruction caused by either benign or malignant PCC÷PGL. We also included a case from our centre that has not been described earlier. We conclude that intestinal pseudo-obstruction is a rare but potentially life-threatening complication of PCC÷PGL. Intravenous administration of phentolamine is the most frequently described treatment when surgical resection of the PCC÷PGL is not feasible.