Fibrotic Lung Toxicity Induced by Hydroxycarbamide.

A patient treated for 4 months with hydroxycarbamide (hydroxyurea) for chronic myelomonocytic leukemia was admitted to hospital for recently developed severe dyspnea and acute respiratory failure. The computed tomographic scan of the chest showed diffuse ground glass opacities, some centrilobular low-density nodules (resembling hypersensitivity pneumonitis-like pattern), and minimal interstitial reticulation of the subpleural region. The analysis of bronchoalveolar lavage fluid excluded infection, as did serological examinations. The patient was started on oxygen therapy and with relief of thrombocytopenia and suspected hemolytic anemia, hydroxyurea treatment was discontinued. The patient underwent steroid therapy, with a rapid progressive improvement of clinical and radiological features. As hydroxyurea is increasingly used for a number of systemic disorders, physicians must be aware of its potential lung toxicity, requiring immediate cessation of the treatment and empiric corticosteroid therapy.

Chronic myelomonocytic leukemia masquerading as cutaneous indeterminate dendritic cell tumor: Expanding the spectrum of skin lesions in chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a hematopoietic stem cell neoplasm exhibiting both myelodysplastic and myeloproliferative features. Cutaneous involvement by CMML is critical to recognize as it typically is a harbinger of disease progression and an increased incidence of transformation to acute myeloid leukemia. Cutaneous lesions of CMML exhibit heterogeneous histopathologic features that can be challenging to recognize as CMML. We describe a 67-year-old man with a 3-year history of CMML who had been managed on single-agent azacitidine with stable disease before developing splenomegaly and acute onset skin lesions. Examination of these skin lesions revealed a dense infiltrate of histiocytic cells morphologically resembling Langerhans type cells (lacking frank histopathologic atypia), and with the immunophenotype of an indeterminate cell histiocytosis (S100+ CD1a+ and langerin-). Given the history of CMML, next-generation sequencing studies were performed on the skin biopsy. These revealed a KRAS (p.G12R) mutation identical to that seen in the CMML 3 years prior, establishing a clonal relationship between the 2 processes. This case expands the spectrum for and underscores the protean nature of cutaneous involvement by CMML and underscores the importance of heightened vigilance when evaluating skin lesions of CMML patients.

18F-FDG PET/CT for staging and detection of extramedullary organ involvement in chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a rare hematologic malignancy characterized by the accumulation of monocytes in the blood and bone marrow, dysplastic hematopoiesis, and potential leukemic involvement of organs. We report a case of leukemic involvement of cervical lymph nodes detected by 18F-FDG PET/CT. A 53-year-old woman with CMML and newly diagnosed cervical lymphadenopathy underwent whole-body PET/CT for evaluation of extramedullary disease. PET demonstrated marked tracer uptake in cervical lymph nodes. Histopathological evaluation revealed leukemic involvement. 18F-FDG PET/CT is a valuable tool enabling sensitive staging of CMML, particularly in case of extramedullary organ involvement.