Unusual presentations of otherwise common hematopoietic neoplasms are a well-recognized diagnostic challenge. Herein, we present a case study of a previously healthy 64 year old woman with myeloid sarcoma whose diagnosis was delayed by an unusual immunohistochemical staining pattern, including cytokeratin expression, by the neoplastic cells and by possible anchoring bias introduced by radiographic and flow cytometric immunophenotyping reports. This case study emphasizes the need to integrate clinical, radiographic, histologic, and immunophenotyping data for rapid and accurate tissue diagnoses while being wary of the lack of specificity for many common immunophenotypic markers.
Keywords: AE1/AE3; CD33; anchoring bias; flow Cytometry; histiocytic sarcoma; immunohistochemistry; melanoma; myeloid sarcoma; poorly differentiated carcinoma.
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