Fig. 1 Left buttock lesion. Sections reveal infiltration of the subcutaneous adipose and collagen by sheets of large monomorphic cells.Fig. 1 Left buttock lesion. Sections reveal infiltration of the subcutaneous adipose and collagen by sheets of large monomorphic cells.
Fig. 2 Left buttock lesion. At high power the cells demonstrate moderate amounts of cytoplasm, irregular or indented nuclear contours, and prominent nucleoli. Frequent mitotic figures and apoptotic cells are seen. Fig. 2 Left buttock lesion. At high power the cells demonstrate moderate amounts of cytoplasm, irregular or indented nuclear contours, and prominent nucleoli. Frequent mitotic figures and apoptotic cells are seen.
Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative. Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative.
Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative. Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative.
Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative. Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative.
Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative. Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative.
Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative. Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative.
Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative. Fig. 3 Left buttock lesion. Immunohistochemistry for CD45, CD33 (Fig. 3a), lysozyme (Fig. 3b), and CD68 (Fig. 3c) were diffusely and strongly positive. CD34 (Fig. 3d), CD117 (Fig. 3e), and myeloperoxidase (Fig. 3f) were not expressed. Additionally, CD56, cytokeratin AE1/AE3, cytokeratin 17, cytokeratin 20, Melan-A, PSA, S-100, CD1a, CD3, CD20, CD21, CD35, CD56, CD123, CD138, CD163, and PAX-5 were negative.
Fig. 4 Bone marrow aspirate. The aspirate demonstrates numerous (59% of nucleated cells) large blasts/blast equivalents. Small mature appearing lymphocytes with clumped chromatin are seen in the background. Fig. 4 Bone marrow aspirate. The aspirate demonstrates numerous (59% of nucleated cells) large blasts/blast equivalents. Small mature appearing lymphocytes with clumped chromatin are seen in the background.
Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).
Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).
Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).
Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).
Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).
Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).Fig. 5 Bone marrow aspirate. Blasts with delicate chromatin and prominent nucleoli (Fig. 5a). Many of the blasts/blast equivalents exhibited large folded or bizarre nuclei (Fig. 5b). There is abundant basophilic cytoplasm with cytoplasmic blebbing and extensive vacuolization (Fig. 5c). Prominent eosinophilic peri-nuclear hofs are present, which range in appearance from collections of eosinophilic granules (Fig. 5d) to collections of small vacuoles (Fig. 5e). Hemophagocytosis is also seen (Fig. 5f).
Fig. 6 Bone marrow core biopsy. Examination revealed a variably hypercellular marrow for age (60%) with effacement of the marrow spaces by sheets of large mononuclear cells. Fig. 6 Bone marrow core biopsy. Examination revealed a variably hypercellular marrow for age (60%) with effacement of the marrow spaces by sheets of large mononuclear cells.
Fig. 7 Bone marrow core biopsy. At higher power these cells exhibited a similar morphologic appearance to that of the cells in the left buttock lesion biopsy with abundant eosinophilic cytoplasm and large irregular nuclei. Many of the nuclei were cleaved or indented and appeared to be pushed to the periphery by brightly eosinophilic cytoplasm.Fig. 7 Bone marrow core biopsy. At higher power these cells exhibited a similar morphologic appearance to that of the cells in the left buttock lesion biopsy with abundant eosinophilic cytoplasm and large irregular nuclei. Many of the nuclei were cleaved or indented and appeared to be pushed to the periphery by brightly eosinophilic cytoplasm.
Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative. Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative.
Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative. Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative.
Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative. Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative.
Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative. Fig. 8 Bone marrow core biopsy. By immunohistochemistry the cells expressed CD45, CD33 (Fig. 8a), muramidase (Fig. 8b), CD99 (Fig. 8c), and focal weak CD68 (Fig. 8d). CD34, CD117 and myeloperoxidase were negative.
Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.
Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.
Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.
Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.Fig. 9 Bone marrow core biopsy. Ill-defined interstitial lymphoid aggregates composed of small mature appearing lymphocytes are noted in addition to the blasts (Fig. 9a). The lymphocytes are positive for CD20 (Fig. 9b) and CD5 (Fig. 9c) by immunohistochemistry. CD3 (Fig. 9d) highlights scattered T-cells.
Fig. 10 Peripheral blood. Numerous mature appearing lymphocytes with coarsely clumped chromatin and smudge cells are present (Fig 10a). Occasional atypical immature mononuclear cells with similar morphologic features to those in the bone marrow are also identified (Fig. 10b). Fig. 10 Peripheral blood. Numerous mature appearing lymphocytes with coarsely clumped chromatin and smudge cells are present (Fig 10a). Occasional atypical immature mononuclear cells with similar morphologic features to those in the bone marrow are also identified (Fig. 10b).
Fig. 10 Peripheral blood. Numerous mature appearing lymphocytes with coarsely clumped chromatin and smudge cells are present (Fig 10a). Occasional atypical immature mononuclear cells with similar morphologic features to those in the bone marrow are also identified (Fig. 10b). Fig. 10 Peripheral blood. Numerous mature appearing lymphocytes with coarsely clumped chromatin and smudge cells are present (Fig 10a). Occasional atypical immature mononuclear cells with similar morphologic features to those in the bone marrow are also identified (Fig. 10b).