Plasma Cell Leukemia with Successful Upfront Venetoclax in Combination with Allogeneic Transplantation.

BACKGROUND Plasma cell leukemia (PCL) is an aggressive form of plasma cell neoplasm. We report the first case of primary PCL successfully treated with upfront novel agents consisting of Venetoclax and daratumumab in combination with intensive chemotherapy and allogeneic transplantation. CASE REPORT A 59-year-old woman presented with epistaxis, gum bleeding, and blurred vision. On examination, she appeared pale, with multiple petechiae and hepatomegaly. Fundoscopy revealed retinal hemorrhages. Laboratory investigations revealed bicytopenia and leukocytosis, with mild coagulopathy and hypofibrinogenemia. Elevated globulin and calcium levels were also observed. Serum protein electrophoresis demonstrated IgG lambda paraproteinemia, with a serum-free light chain kappa-to-lambda ratio of 0.074. A skeletal survey revealed the presence of lytic lesions. Bone marrow investigations confirmed the presence of lambda-light-chain-restricted clonal plasma cells. FISH detected t(11;14) and 17p13.1 deletion. Therefore, a final diagnosis of primary PCL was made. The patient received 1 cycle of bortezomib, cyclophosphamide, and dexamethasone (VCD) and 5 cycles of Venetoclax-VCD, followed by an unsuccessful stem cell mobilization. One cycle of daratumumab in combination with bortezomib, lenalidomide, and dexamethasone (VRD) was then given. The patient achieved complete remission. She underwent allogeneic stem cell transplantation of an HLA-matched sibling donor. Post-transplant marrow assessment showed disease remission and absence of t(11;14) and 17p deletions. She was administered pamidronate and lenalidomide maintenance. She remained clinically well with a good performance status and no active graft-versus-host disease 18 months after transplant. CONCLUSIONS The success of our patient in achieving complete remission has highlighted the efficacy and safety of this novel therapy in the front-line management of PCL.

Trichobezoar masquerading as massive splenomegaly: Rapunzel's syndrome revisited.

Trichobezoars are usually formed due to ingestion of hair or hair-like fibres and present with a wide spectrum of clinical manifestations. We report a case of Rapunzel's syndrome associated with trichotillomania in a 16-year-old girl who presented to our Haematology unit with complaints of fatigue, abdominal distention, and early satiety. Initial evaluation demonstrated anaemia, thrombocytosis, and a left hypochondrial mass suggestive of splenomegaly. However, ultrasound of the abdomen showed no hepatosplenomegaly and blood investigations were not suggestive of haematological malignancy. Not long after, the patient presented to the emergency department with suspected acute abdomen. Computed tomography of the abdomen revealed intraluminal gastric and jejunal masses causing small bowel obstruction. Emergency laparotomy confirmed gastric and jejunal trichobezoars, and subsequent psychiatric evaluation confirmed trichotillomania. Clinicians should consider trichobezoar in the differential diagnosis of abdominal pain and a non-tender 'spleen-like' abdominal mass.

Improved CRISPR/Cas9 knock-in efficiency via the self-excising cassette (SEC) selection method in C. elegans.

Streamlined, selection-based CRISPR knock-in protocols for C. elegans were first introduced six years ago (Dickinson et al. 2015; Schwartz and Jorgensen 2016). Though these selection-based approaches are powerful, one drawback has been the requirement to inject large numbers of P0 worms (~30-60 per gene target). We have found that a combination of high-purity DNA and a lower concentration of Cas9/sgRNA plasmid dramatically improves efficiency, often resulting in multiple independent CRISPR knock-ins via as few as 10 injected worms, comparable to the efficiency of melted dsDNA templates and purified Cas9 protein (Dokshin et al. 2018; Ghanta and Mello 2020).