dacrocytosis

Dacrocytosis refers to the presence of dacryocytes, teardrop-shaped red blood cells, on a peripheral blood smear. These abnormally shaped cells result from distortion of developing erythrocytes as they pass through a bone marrow environment that is fibrotic, infiltrated, or otherwise rigid, and they are often part of a leukoerythroblastic blood picture.

Dacrocytosis is most strongly associated with disorders that cause bone marrow fibrosis or infiltration, particularly primary myelofibrosis. It can also be seen in secondary myelofibrosis due to metastatic cancer or other marrow-infiltrative or granulomatous diseases. The finding is not pathognomonic and may occur in various other conditions that disrupt erythropoiesis or marrow architecture; thus it should prompt further diagnostic evaluation rather than serve as a standalone diagnosis.

Evaluation generally includes a complete blood count to assess anemia and cytopenias, examination of a peripheral smear, and escalation to bone marrow examination to assess fibrosis and cellularity. Molecular testing for myeloproliferative neoplasms, including JAK2, CALR, and MPL mutations, is often performed when myelofibrosis is suspected, as these mutations can influence prognosis and treatment.

Management focuses on treating the underlying cause. In primary myelofibrosis or other fibrotic/infiltrative marrow disorders, treatment may include disease-modifying therapies (for example, JAK inhibitors such as ruxolitinib), cytoreductive approaches when indicated, and supportive care such as transfusions and management of splenomegaly. Prognosis varies with the underlying condition and overall clinical context.