Pneumonitis associated with bortezomib in a patient with multiple myeloma.

INTRODUCTION: Bortezomib, which is widely used in the treatment of multiple myeloma (MM), is a proteasome inhibitor and acts by inducing apoptosis. Bortezomib has many side effects, mainly hematological, neurological, and gastrointestinal. A few cases of bortezomib-induced pneumonitis (BIP) have been reported in the literature. CASE REPORT: A 51-year-old male patient who was newly diagnosed with MM received bortezomib, cyclophosphamide, and dexamethasone as first-line therapy. In the first cycle, the patient developed dyspnea, tachypnea, and hypoxia after the fourth day of administration of bortezomib monotherapy according to the treatment protocol. MANAGEMENT AND OUTCOME: Infection and pulmonary involvement of MM were excluded after radiological evaluations, and a diagnosis of BIP was made. Clinical control was achieved quickly with steroid therapy and oxygen support, and radiological findings improved with treatment. Due to this rare side effect of bortezomib, the treatment regimen containing bortezomib was changed. The patient is still receiving treatment that does not contain bortezomib and does not have any pulmonary problems. DISCUSSION: In cancer patients receiving treatment, infection and metastasis should be quickly ruled out when pulmonary problems occur, and drug-induced pneumonitis should be considered. This diagnosis, which often responds dramatically to steroids, has the potential to have serious consequences when not considered. In this case, we present bortezomib-associated pneumonitis, a rare side effect of bortezomib. The most important feature of this case is the development of this side effect at the beginning of the treatment, unlike other cases reported in the literature.

Rituximab-induced severe acute thrombocytopenia in a patient with splenic marginal zone lymphoma.

INTRODUCTION: Rituximab, which is widely used in the treatment of B-cell lymphoma, is a chimeric monoclonal antibody directed against the CD20 antigen. Rituximab has many side effects, mainly allergic and neurological. Rituximab may cause thrombocytopenia in the long term after administration. Rare cases of rituximab-induced acute thrombocytopenia have been reported in the literature. CASE REPORT: A 51-year-old female patient who was newly diagnosed with splenic marginal zone lymphoma received rituximab as first-line therapy. Petechiae occurred in the lower extremities on the day following rituximab administration. The blood test showed a severe drop in the platelet count from 112,000/µL to 5000/µL. Blood peripheral smear evaluation confirmed severe thrombocytopenia. MANAGEMENT AND OUTCOME: There was no change in hemoglobin or white blood cell levels. After the diagnosis of rituximab-induced acute thrombocytopenia, thrombocyte suspension was administered due to the risk of bleeding. Close clinical and laboratory observations were made. The platelet count began to rise gradually in the following period. Before the second week of rituximab administration, the platelet count was 122,000/µL. No complications developed after premedication and slow rituximab administration, and subsequent treatments were continued in the same way. DISCUSSION: Rituximab has widespread use, especially in malignancies and autoimmune diseases. Like many monoclonal antibodies, rituximab has several side effects. Thrombocytopenia is a long-term side effect associated with rituximab, and rituximab-induced severe acute thrombocytopenia has been rarely reported. Therefore, it should be kept in mind that severe acute thrombocytopenia may develop after rituximab administration.