Acute myelomonocytic leukemia with histologic features resembling sarcomatoid carcinoma in bone marrow

We report a case of primary acute myelomonocytic leukemia involving the bone marrow that resembled sarcomatoid carcinoma. The neoplastic cells in bone marrow biopsy specimens formed cohesive-appearing clusters and cords separated by an immature fibroblastic proliferation and myxoid stroma. Blasts in the bone marrow aspirate smears formed clusters and sheets, and a subset of blasts exhibited erythrophagocytosis. Dysgranulopoiesis was also present. Lineage was confirmed by immunohistochemical analysis of formalin-fixed, paraffin-embedded tissue. The tumor cells showed strong reactivity for lysozyme, myeloperoxidase, CD45, and CD68 and were negative for keratin, S100, CD20, and CD3. The serum lysozyme concentration (110 microgram/mL) was 13 times greater than the normal value (8 microgram/mL). Cytogenetic studies performed on bone marrow aspirate material revealed a complex karyotype, including trisomy 8 and abnormalities of chromosome 11q. We report this case of acute myelomonocytic leukemia because the neoplastic cells appeared cohesive and spindled, resembling sarcomatoid carcinoma, and therefore caused diagnostic difficulty. Other monocytic neoplasms with similar resemblance to carcinoma or sarcoma have been reported in the literature, suggesting that the tendency to appear cohesive may be an inherent characteristic of neoplastic cells with monocytic differentiation.     

Interdigitating dendritic reticulum cell sarcoma: cytologic, histologic and immunocytochemical features

Tumors of dendritic reticulum cells are rare neoplasms that exhibit significant morphologic overlap with other malignancies. Fine-needle aspiration cytologic appearances of this neoplasm are not well understood. A 33-yr-old woman presented with a rapidly growing nodular mass in the right upper cervical region and right-sided ptosis. Fine-needle aspiration cytology of the mass showed dissociated as well as clustered, large, polygonal cells that showed high nuclear-cytoplasmic ratio. Nuclei were round, oval, or irregular in shape. Large and small blastoid forms with prominent nucleoli and chromatin clumping as well as binucleated cells and cells with lobulated nuclei were seen. Numerous mitoses were observed. The tumor cells expressed focal immunocytochemical reactivity to CD45 and CD68, but were negative for CD2, CD3, CD4, CD8, CD20, CD30, CD45RO, epithelial membrane antigen (EMA), cytokeratin, and HMB45. Histologic sections of the biopsy from the growth showed nodal tissue effaced by a tumor composed of large, pleomorphic neoplastic cells with some binucleate and multinucleate forms resembling Reed-Sternberg cells. The intervening stroma contained numerous small lymphocytes. Tumor cells expressed vimentin, S-100 protein, CD68, and MAC387, but were negative for LCA, CD1a, CD3, CD15, CD20, CD21, CD23, CD30, CD35, carcino-embryonic antigen, HMB45, cytokeratin AE1/3, EMA, myeloperoxidase, lysozyme, smooth-muscle actin, and desmin. The combined histologic and immunohistologic features suggested a histiocytic/dendritic reticulum cell neoplasm and a diagnosis of interdigitating dendritic reticulum cell sarcoma was made.     

Plasma cell myeloma with cleaved, multilobated, and monocytoid nuclei

The neoplastic cells in most cases of multiple myeloma closely resemble normal plasma cells. The authors report six cases of myeloma in which most of the neoplastic cells had cleaved, multilobated, or monocytoid nuclei and presented some diagnostic difficulty. All cases were clinically aggressive (five patients with stage III disease and one patient with stage II disease). Three patients died during their initial hospitalization, and three patients are alive with progressive disease from 5 to 14 months after combination chemotherapy. Immunohistochemical studies on paraffin-embedded tissue demonstrated monotypic immunoglobulin in each case (three lambda and three kappa). Recognition of these morphologic variants of neoplastic plasma cells is important to the pathologist to avoid erroneous diagnoses and to alert the clinician to an aggressive form of myeloma associated with a poor prognosis. Immunohistochemical studies on paraffin-embedded tissue sections are useful in the diagnosis of this tumor.     

A case of aggressive multiple myeloma with cleaved, multilobated, and monocytoid nuclei, and no serum monoclonal gammopathy

Multiple myeloma is a B-cell malignancy characterized by proliferation of neoplastic plasma cells. A few cases have been reported identifying variant forms of neoplastic plasma cells with atypical nuclei that secrete myeloma protein. We report a highly unusual case of plasma cell myeloma that presented with cleaved, multilobated, and monocytoid nuclei, without detectable myeloma protein in the serum or urine. The bone marrow contained sheets of plasma cells exhibiting pleomorphic nuclei with cleaved, multilobated, and monocytoid features that were negative for myeloperoxidase and dual esterase. Flow cytometric analysis revealed CD38high/CD45low cells expressing cytoplasmic kappa light chain, without evidence of myeloid or lymphoid differentiation. Following chemotherapy, the patient developed secondary plasma cell leukemia. A high plasma cell labeling index was obtained from bone marrow and peripheral blood, indicating a poor prognosis. In addition to quantitative immunoglobulins, serum protein electrophoresis, and immunofixation electrophoresis of serum and urine, we recommend cytochemical and flow cytometric studies for evaluation of suspected plasma cell myeloma with atypical cellular features.     

Plasma cell granuloma of the thyroid

Plasma cell infiltrates in the thyroid are rare. They may represent several processes, such as localized plasmacytoma, multiple myeloma, or plasma cell granuloma (PCG). It may be difficult to distinguish these disorders on the basis of morphologic features in sections stained with hematoxylin-eosin. All may be composed of mature plasma cells, without admixed macrophages or lymphocytes, that infiltrate the thyroid and adjacent connective tissue. The identification of the uncommon, but benign, PCG is facilitated by immunohistochemical staining to demonstrate an admixture of plasma cells with cytoplasmic kappa and lambda light chains. The polyclonal nature of the plasma cell infiltrate distinguishes PCG from neoplastic plasma cell proliferation.     

Malignant granular cell tumor of soft tissues: a study of two new cases

We describe 2 cases of malignant granular cell tumor. A marked discrepancy exists concerning the criteria of malignancy of this rare entity, which was diagnosed in male patients aged 41 and 52 years, respectively. They presented with tumors measuring more then 3.5 cm; one arose in the dermis and subcutaneous tissue in the region of the scapula, whereas the other was situated in deeper soft tissue in the pelvis. One case, with previous diagnosis of benign granular cell tumor, presented local recurrence 2 years after the initial diagnosis. The other case presented a fascicular pattern of growth invading adjacent muscular tissue. Both neoplasms were composed of polygonal and spindle cells, showing abundant cytoplasm, vesicular nuclei with large nucleoli, high nuclear-to-cytoplasmic ratio, and pleomorphism. Immunohistochemically, the neoplastic cells of both cases were positive for vimentin, S100 protein, neuron-specific enolase (NSE), and CD68. In addition, high expression of p53 and MiB1 (Ki67) was detected. Herein, we discuss the morphologic and immunohistochemical criteria of malignancy of granular cell tumors. Int J Surg Pathol 9(3):255-259, 2001     

Histiocytic sarcoma associated with idiopathic myelofibrosis

We describe the case of a 39-year-old man with idiopathic myelofibrosis, who developed histiocytic sarcoma (true histiocytic lymphoma) 6 months after diagnosis. The patient developed generalized lymphadenopathy. A lymph node biopsy showed pronounced distension of the sinuses in the medulla and periphery, caused by the accumulation of large tumor cells. The tumor cells had abundant clear or eosinophilic cytoplasm. The nuclei were of various sizes and shapes, with condensed chromatin and prominent nucleoli. Some tumor cells displayed erythrophagocytosis. Immunohistochemically, the tumor cells were positive for CD68, alpha(1)-antitrypsin, CD45, CD45RO, and S100 protein, and were negative for B- and T-cell markers, CD30, CD1a, lysozyme, myeloperoxidase, factor VIII-related antigen, CAM 5.2, and HMB-45. Despite multiagent chemotherapy, the patient died of disease 25 months after diagnosis. Although histiocytic sarcomas are very rare, their recognition may be important for clinical and prognostic reasons.     

浆细胞肿瘤病理形态的多样性

目的 观察浆细胞肿瘤的病理形态学特点,探讨其组织结构和细胞形态的类型及其鉴别诊断.方法应用HE、免疫组织化学(EliVision法),对46例浆细胞肿瘤的组织形态学及免疫表型进行研究.结果 46例浆细胞肿瘤中,有40例组织结构以弥漫分布为主,3例呈巢状结构而似神经内分泌肿瘤,3例出现硬化的纤维性背景.淀粉样物质沉积、钙化骨化及"血湖"样结构在部分病例中有可能会非常突出而掩盖了肿瘤性浆细胞的特点.细胞形态上,30例由较成熟和欠成熟的浆样细胞组成而较易辨认.6例由类似免疫母细胞的浆母细胞组成.4例肿瘤细胞较小,似小淋巴细胞.2例瘤细胞胞质透亮似透明细胞或印戒细胞.另各有1例分别由异型性明显的间变型细胞、组织细胞样细胞及梭形细胞构成.最后1例细胞形态多样,可出现分叶核、单核及多核型细胞.免疫表型上93.1%(27/29)的病例表达CD79a而仅有5.1%(2/39)的病例表达CD20,87.1%(27/31)的病例表达CD38和83.3%(25/30)表达CD138,96.8%(30/31)的病例表达MUM-1.38例呈免疫球蛋白轻链限制性表达,其中表达λ链27例,表达κ链11例.结论浆细胞肿瘤除了常见的组织形态外,还可出现不典型或少见的组织结构和细胞形态,诊断时应注意与其他类型淋巴瘤如小淋巴细胞淋巴瘤及间变性大细胞淋巴瘤、低分化癌、透明细胞或印戒细胞癌、间叶性肉瘤等进行鉴别,免疫组织化学是必不可少的.     

Intra-abdominal follicular dendritic cell sarcoma with marked pleomorphic features and aberrant expression of neuroendocrine markers: report of a case with immunohistochemical analysis.

Follicular dendritic cell sarcoma (FDCS) is a very rare malignant tumor arising most frequently in lymph nodes with only few reports of extranodal locations. We report the case of a 35-year-old man with a large retroperitoneal mass. Histologically the tumor was composed of highly pleomorphic cells exhibiting some uncommon features such as an epithelioid appearance, cystic spaces, and multinucleated cells with morphologic features of emperipolesis. Immunohistochemically the neoplastic cells were immunoreactive for CD21, CD23 and CD35. A previously unreported expression of neuroendocrine markers (Synaptophisyn and Neuron-Specific-Enolase) was present. Ultrastructurally no neuroendocrine secretory granules were detected. FDCS can mimic a wide variety of other malignant tumors, and a correct diagnosis requires exclusion of other neoplasms and immunohistochemical confirmation.     

CD30(Ki-1) antigen expression in a subset of gastric mucosal plasma cells and in a primary gastric plasmacytoma

With the use of frozen sections, 24 different monoclonal antibodies (MoAbs), and an indirect peroxidase technique, the antigenic profile of a well-differentiated primary gastric plasmacytoma was obtained. Corresponding to the normal plasma cell, tumor cells were devoid of HLA-D products and B-cell-restricted differentiation antigens CD19, CD20, CD21, CD22, and CD23 while expressing plasma cell-associated CD24 and CD38 molecules and IgA/lambda. The plasmacytoma furthermore reacted with CD30(Ki-1), a reactivity that for this tumor type has not been reported before. Subsequently, normal gastric mucosae affected by all degrees of chronic gastritis were examined. On the basis of serial sections, 5-15% of CD38(OKT10) reactive mucosal plasma cells were observed to also react with CD30(Ki-1). The authors conclude that the CD30 antigen is not only an activation antigen but is also expressed on a subset of terminally differentiated plasma cells.     

Malignant melanoma with a rhabdoid phenotype: histologic, immunohistochemical, and ultrastructural study of a case and review of the literature

Malignant melanoma is known to display tremendous histologic diversity. One rare variant is the rhabdoid phenotype, so called because of the appearance of cells resembling rhabdomyoblasts seen in malignant rhabdoid tumors of the kidney. We present the histologic, immunohistochemical, and ultrastructural features of a malignant melanoma composed entirely of rhabdoid cells. A 62-year-old man presented with a 6.5-cm lung mass. Although presumed to be a metastatic lesion, extensive workup failed to reveal a primary tumor site. Histologic sections showed a mass composed entirely of polygonal neoplastic cells with prominent nucleoli and large hyaline cytoplasmic inclusions. The tumor cells were strongly immunoreactive with S100 protein, vimentin, and CD56, and were focally reactive with Mart-1. Tumor cells were negative for Melan-A, tyrosinase, HMB-45, AE1/AE3, cytokeratin (CK) 7, CK8/ 18, CK20, CK903, CAM 5.2, epithelial membrane antigen, smooth muscle actin, desmin, leukocyte common antigen, Bcl-2, CD3, CD20, CD30, CD138, kappa and lambda light chains, CD68, CD34, factor VIII, synaptophysin, and glial fibrillary acidic protein. Electron microscopy showed cytoplasmic whorls of intermediate filaments containing entrapped rough endoplasmic reticulum, mitochondria, and lipid. Recognition of this rare variant of malignant melanoma is important in the evaluation of tumors with rhabdoid morphology.     

Plasmablastic lymphoma of the cecum: Report of a case with cytologic findings

Plasmablastic lymphoma (PBL) is a rare lymphoma that is characterized by a diffuse proliferation of large neoplastic cells resembling B immunoblasts, but shows the immunophenotype of plasma cells. PBL is most commonly seen in the oral cavity of human immunodeficiency virus (HIV)‐positive patients. Epstein‐Barr virus (EBV) may be closely related the pathogenesis of PBL. We report a case of HIV‐negative PBL in a 75‐year‐old man without EBV infection. Histologic examination of the cecal tumor following right hemicolectomy and cytologic examination of ascitic fluid were performed. Cytologic specimens were hypercellular and composed of single cells and loosely formed clusters. Large tumor cells showed plasmacytoid features with basophilic cytoplasm, large nuclei, prominent nucleoli, and focal perinuclear halos. Abnormal mitotic figures were easily identified. On immnohistologic study, the tumor cells were positive for CD138 (plasma cell marker) and kappa, but negative for CD45, CD3, CD20, CD79a, CD56, and cyclin D1. The proliferation index (Ki‐67) was high. This is a very rare case of PBL without HIV and EBV infection, involving the cecum. Diagn. Cytopathol. 2011;39:297–300. © 2010 Wiley‐Liss, Inc.     

Askin tumor with metastasis to the scalp: a histochemical, immunohistochemical and ultrastructural study

A 29-year-old woman presented with facial edema, and imaging disclosed a tumor extending from the anterior chest wall to the anterosuperior aspect of the mediastinum. Transbronchial cytology of the primary tumor and biopsy of the metastatic scalp lesion were performed. Histologically, the tumor consisted of closely packed small round cells. The neoplastic cells generally had round nuclei, finely dispersed chromatin, and small to prominent nucleoli. Histochemically, the cytoplasm of the neoplastic cells contained abundant glycogen and stained with Grimelius silver. Immunohistochemically, the neoplastic cell membranes reacted with CD99 (MIC2) and the neoplastic nuclei reacted with Fli-1, but various other markers, including lymphocyte and skeletal muscle markers, were not detected. No neoplastic cells were also reactive for chromogranin A, synaptophysin, and neurofilament. Ultrastructurally, some neoplastic cells had delicate cytoplasmic processes and contained membrane-bound dense core granules in the cytoplasm. Even if results are immunohistochemically negative for neuroendocrine markers, the combination of immunohistochemistry of CD99 (MIC2) and Fil-1 may be useful in diagnosing Askin tumor or its metastatic lesion.     

IgG4 Overexpression Is Rare in Meningiomas with a Prominent Inflammatory Component: A Review of 16 Cases

Meningiomas with prominent inflammation are traditionally classified as “lymphoplasmacyte‐rich meningioma” (LPM). Both inflammatory and neoplastic meningeal proliferations have recently been linked to IgG4 disease, although a potential association with LPM has not been previously explored. Sixteen meningiomas with inflammatory cells outnumbering tumor cells were further characterized by CD3, CD20, CD68 and/or CD163, CD138, kappa, lambda, IgG and IgG4 immunostains. There were 11 female and 4 male patients, ranging from 22 to 78 (median 59) years of age. Tumors consisted of 10 World Health Organization (WHO) grade I, 5 grade II and 1 grade III LPMs. Immunohistochemically, the most numerous cell type was the macrophage in all cases followed by CD3‐positive T cells and fewer CD20‐positive B cells. Plasma cells ranged from moderate‐marked (N = 5) to rare (N = 7), or absent (N = 4). Maximal numbers of IgG4 plasma cells per high power field (HPF) ranged from 0 to 32, with only two cases having counts exceeding 10/HPF. The IgG4/IgG ratio was increased focally in only two cases (30% and 31%). Additionally, plasma cells represented only a minor component in most examples, whereas macrophages predominated, suggesting that “inflammation‐rich meningioma” may be a more accurate term. The inflammatory stimulus for most cases remains to be elucidated.     

Interleukin-2 receptor antigen, leukocyte common antigen, and Ki-1 antigen-expressing gastric plasmacytoma. A case report with an immunohistochemical study.

A case of primary gastric plasmacytoma expressing various surface and cytoplasmic antigens is reported. With the use of formalin-fixed and deparaffinized sections, 13 different antibodies were applied. Neoplastic plasma cells revealed monoclonal IgG and kappa light chain in the cytoplasm, and expressed epithelial membrane antigen, Ki 67 antigen, cytokeratin, CD 22 antigen, interleukin-2 receptor antigen, leukocyte common antigen and Ki-1 (CD 30) antigen. However, tumor cells were devoid of HLA-DR antigen. These data suggest that the neoplastic plasma cells are at the plasmoblastic stage of maturation and express various surface and cytoplasmic phenotypes.     

CK阳性T细胞淋巴瘤1例报道并文献复习

目的 研究CK呈阳性表达的非霍奇金小T细胞性淋巴瘤的病理学特征及鉴别诊断。方法 运用光镜、电镜及免疫组化技术，观察1例CK呈阳性表达非霍奇金小T细胞性淋巴瘤的组织学、超微结构形态及免疫组化特征并复习相关文献。结果 肿瘤组织主由弥漫分布的小圆形细胞构成。核仁不明显。CD45、CD45RO、和CK(广谱、低分子量、高分子量和19、)均为( )。CD20和CD79均为(-)。电镜观察瘤细胞胞核圆形，居中。胞质少．可见线粒体．未见上皮细胞分化特征、神经内分泌颗粒。结论 非霍奇金小T细胞性淋巴瘤偶可呈CK阳性表达，在应用免疫组化技术对低分化肿瘤进行鉴别诊断时应注意肿瘤组织的异常表达。     

Ultrastructural localization of the CD68 macrophage-associated antigen in human blood neutrophils and monocytes.

The ultrastructural localization of the CD68 antigen, a 110-kd intracellular glycoprotein associated with myeloid cells and with monocytes/macrophages, was investigated in human neutrophil granulocytes by postembedding immunogold staining, using monoclonal antibody KP1. The antigen was found in the primary granules of neutrophils, although not all primary granules were labeled. It was absent from the plasma membrane. In monocytes, it was also detected within cytoplasmic granules, colocalized with lysozyme and myeloperoxidase. This observation confirms and completes results obtained by immunofluorescence and other light-microscopic methods. Moreover this study shows that the CD68 epitope recognized by antibody KP1 is able to resist fixation and embedment and therefore emphasizes the value of using KP1 as a marker for this macrophage-associated molecule.     

Nodal marginal zone B-cell lymphoma resembling plasmacytoma arising from a plasma cell variant of localized Castleman's disease: a case report

Nodal marginal zone B-cell lymphoma (NMZBL) occasionally represents prominent plasma cell differentiation. Recently, primary lymph node plasmacytoma has been suggested to represent an extremely plasmacytic differentiation of NMZBL. We here report a case of NMZBL showing histological features resembling plasmacytoma arising from a plasma cell variant of localized Castleman's disease (PCLCD). The patient was a 69-year-old Japanese female with a 20-year history of a right inguinal mass. Histologically, a prominent proliferation of plasma cells occupied the interfollicular area of the central portion of the lymph node, whereas centrocyte-like (CCL) cells were the main cellular component in the peripheral portion of the lymph node. Although most of the plasma cells were mature 'Marshalko-type', occasional atypical forms with enlarged nuclei were also present. The majority of the lymphoid follicles had atrophic or regressive germinal centers. A few lymphoid follicles were colonized by CCL cells. Immunohistochemistry study revealed that both plasma cells and some CCL cells had a monotypic intracytoplasmic lambda light chain. When monoclonal plasma cell infiltration is observed in PCLCD, the light chains are mostly restricted to the lambda chain. This case suggests that some plasma cell-containing tumors arising from PCLCD may represent a variant of NMZBL.     

Follicular dendritic cell tumor with histiocytic characteristics and fibroblastic antigen

A report is presented of a follicular dendritlc cell (FDC) tumor arising In the lymph nodes and Inguen of a 55-year-old Japanese female, who had suffered from schizophrenla for 25 years. The left submandibular lymph nodes had completely lost their normal architecture, except for the capsule, due to tumor cell infiltration. Occaslonal nodular structures resembling epltheliold granulomas, attributable, at least In part, to follicular Involvement of tumor cells, were observed. These nodules were composed of epithellold- or fibroblast-like tumor cells forming interwoven fascicles, to which small lymphocytes were attached. Tumor cells were also scattered in the internodular areas. For more atyplcal tumor cells, arranged in a sheet-like structure, were present In the inguinal specimen, the tumor cells of which expressed Ki-M4p, CD21, CD35 and other antigens known to be expressed on FDC. Furthermore, they also expressed the monocytdmacrophage antlgens, α1-antltrypsin, α-antlchymotrypsin, lysozyme, CD14, CD33, CD68 and Mac387 and fibroblastic antigen. Ultrastructural studies demonstrated lysosomal granules as well as a few desmosomes, Indicating the tumor cells possessed fibrohistiocytic and FDC characteristics.     

Interdigitating dendritic cell tumor with breast and cervical lymph-node involvement: a case report and review of the literature

Interdigitating dendritic cell tumor (IDCT) is an extremely rare malignancy. It occurs primarily in lymph nodes, but extranodal involvement has also been reported. A 38-year-old woman with IDCT with breast and cervical lymph-node involvement is reported in this paper. To our knowledge, this is the first case of IDCT originating from the breast. In the breast and lymph node, the tumor displayed diffuse sheets, fascicles and storiform growth pattern. It was composed of oval to spindle cells with pale to eosinophilic cytoplasm, ill-defined cell outlines, oval nuclei with vesicular chromatin and prominent eosinophilic nucleoli. Mitotic activity was three per ten high-power fields. The neoplastic cells were intermingled with small mature lymphocytes and plasma cells. Immunohistochemical studies showed that the tumor cells were strongly and diffusely positive for vimentin, CD68, S-100 protein, CD45/leukocyte common antigen and fascin and focally positive for lysozyme, alpha-1 antitrypsin and CD4. Ki-67 labeling index was 10%. The patient was treated with combined therapeutic approaches, including surgery, radiotherapy and chemotherapy. IDCT has the potential for an aggressive clinical course. However, 32 months after the initial diagnosis, the patient is still alive and being followed with a stable tumor burden.