Primary Histiocytic Sarcoma Presenting as a Breast Mass: A Case Report / 한국유방암학회지

Histiocytic sarcoma is a rare hematologic malignancy, with very few cases of primary histiocytic sarcoma of the breast described in English scientific literature. Herein, we describe a case of primary histiocytic sarcoma of the breast in a 75-year-old woman, with no clinical history of malignant tumors, who presented with a palpable solitary breast mass. Microscopically, the resected breast mass showed large pleomorphic cells, some multinucleated giant cells, and admixed inflammatory components. The pleomorphic tumor cells further showed a diffuse, noncohesive growth pattern, an abundant eosinophilic cytoplasm, and strong and diffuse immunoreactivity for cluster of differentiation (CD) 68 and CD163. Furthermore, a whole-body positron-emission tomography/computed tomography using deoxy-2-[¹⁸F]fluoro-D-glucose performed after surgery showed no other masses or lesions. After surgical excision, the patient was followed up, and no evidence of tumor recurrence or metastasis was noted.

Histiocytic Sarcoma of the Cervical Spinal Cord with Secondary Involvement of the Skin / 대한피부과학회지

Histiocytic sarcoma is a rare, lymphohematopoietic malignant tumor comprised of tumor cells with the morphological and immunophenotypic features of mature histiocytes. A 35-year-old man presented with a disseminated histiocytic sarcoma that first occurred in the spinal cord and metastasized to the skin and lymph nodes. The tumor cells of the primary histiocytic sarcoma of the spinal cord were very large epithelioid cells with abundant eosinophilic cytoplasms and large, round-to-oval nuclei. In contrast, the metastatic histiocytic sarcoma of the skin was composed of relatively small polygonal cells with well-defined cell borders and high N/C (nucleus/cytoplasm) ratios. Immunohistochemically, both tumors were diffusely positive for histiocyte-associated antigens; but negative for epithelial, melanocyte, lymphoid, and dendritic cell antigens. It is important to recognize the morphological features and immunohistochemical characteristics of metastatic cells in order to ensure accurate diagnoses.