Acquired Hemophilia A (AHA) is a very rare autoimmune condition involving immune-mediated depletion of Factor VIII, resulting in spontaneous hemorrhage. Failure to recognize AHA as a possible etiology of hemorrhage can result in delayed diagnosis and treatment. The COVID-19 pandemic has given rise to several hematologic conditions and complications, with a rare manifestation being Acquired Hemophilia A (AHA). An interesting case of AHA following SARS-CoV-2 infection is described, along with the treatment approach and a brief review of several cases describing AHA in association with COVID-19.

502 Background: Right-sided colon cancers (RCC) are defined up to the splenic flexure where as left-sided colon cancers (LCC) involve the descending, sigmoid, and rectosigmoid regions. The landmark CALGB/SWOG 80405 study concluded that sidedness was an independent prognostic factor for survival in stage IV adenocarcinoma of the colon or rectum, with a poorer prognosis in RCC. This raises the question as to whether or not stage of malignancy plays a role. We performed a retrospective analysis on survival for stage I to IV colon cancer treated at our institution in order to assess if tumor location is an independent prognostic factor as described in previous studies. Methods: Primary site of cancer, sex, age at diagnosis, vital status, and year of diagnosis for stage I, II, III, and IV colon cancer was collected from our institution’s tumor registry from 2007 to 2017. The inclusion criteria included those diagnosed with stage I to IV colon cancer at 18 years of age and above. Exclusion criteria included a diagnosis of both RCC and LCC and patients under age 18. The median of overall survival and time to recurrence between LCC and RCC were compared using Wilcoxon Rank Sum Test with two-sided significance level at 0.05. Results: Time to overall survival and time to recurrence was shown to have no significant difference between RCC and LCC (p = 0.3398 and 0.9467, respectively). Cox proportional hazards model adjusted for age and sex also support the claim (p = 0.1725 and 0.0633). There was a statistically significant difference in age between the two groups with the older mean age seen in RCC (68 versus 62). The distribution of recurrence was statistically significant with a higher recurrence in RCC (p = 0.0105). Conclusions: Unlike CALGB/SWOG 80405, our analysis included the transverse colon as part of RCC and examined stage I to IV colon cancer to ultimately conclude that there was no significant difference in overall survival or time to recurrence. Our study suggests that tumor location is not an independent prognostic factor on survival for all stages of colon cancer. However, a higher suspicion for recurrence may be needed for those diagnosed with RCC. Future investigations involving molecular subtypes and mutations are needed to further clarify prognosis and tumor sidedness.

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of widespread inflammation due to massive amounts of cytokines released from activated macrophages. The most common trigger for HLH is infection from a virus, most commonly Epstein-Barr virus. Here we report an adult case of this rare and life-threatening syndrome.

A promising drug, palbociclib, received accelerated approval as a first line treatment when used with the aromatase inhibitor, letrozole, for postmenopausal women with hormone receptor positive advanced or metastatic breast cancer. We report a case of a patient who presented with febrile neutropenia, grade 3 stomatitis with lip swelling, periorbital edema, and transaminitis while on palbociclib and verapamil. Labs normalized upon discontinuation of verapamil and our patient was able to continue treatment with palbociclib and letrozole. Verapamil's inhibition of both permeability-glycoprotein (P-gp) and CYP3A4 is suspected to have led to the adverse side effects seen in our patient.

Methotrexate is a widely used chemotherapy agent with a propensity for drug interactions placing the patient at risk for toxicities. There are several modes for altering methotrexate clearance including concomitant drugs leading to toxic effects on the kidneys, medications producing an acidic urine pH, and agents interfering with methotrexate transporters including the organic anion transporter and breast cancer resistance protein efflux pump. We report a case of a patient with central nervous system non-Hodgkin's lymphoma receiving high-dose methotrexate and being concomitantly treated for a urinary tract infection with nitrofurantoin. Subsequently, her initial methotrexate clearance was altered by the introduction of nitrofurantoin and returned to baseline when her nitrofurantoin was discontinued. This is the first case report describing the altered methotrexate clearance from concurrent administration of methotrexate and nitrofurantoin.