Follicular dendritic cell tumor of the mesentery

Follicular dendritic cell (FDC) tumor is an exceedingly rare malignant neoplasm and occurs mainly in the cervical lymph nodes. We report a mesenteric FDC tumor occurring in a 66-year-old female, that manifested with intraabdominal multifocal recurrence 7 years after resection of the primary tumor. Histologically, both primary and recurrent tumors were composed of oval to spindle cells with paley eosinophilic cytoplasms, indistinct cell borders, round to elongated nuclei with clear or finely dispersed chromatin, and medium to large nucleoli. Characteristically, the tumor cells were growing in sheets, fascicles, and sometimes in whorls and a storiform pattern. In addition, focal necrosis, nuclear pleomorphism and abnormal mitoses were also observed. The neoplastic cells were intimately admixed with small lymphocytes. The diagnosis was confirmed by positive immunoreactivity with CD21 and CD35 antibodies and by ultrastructural demonstration of convoluted interdigitating cell processes connected by scattered desmosome-like junctions. Although our case showed a low proliferative activity evaluated by MIB-1, multifocal recurrence has occurred. The clinicopathologic features and differential diagnosis of FDC tumors are discussed with the review of the literature.     

Cytological distinction between clear cell carcinoma and yolk sac tumor of the ovary

Cytological characteristics of clear cell carcinoma (CCC) and yolk sac tumor (YST) of the ovary were examined and compared. Indices for differential diagnosis of these two histologically similar but biologically different tumors were analyzed based on cytological features of the tumor cells. The main results obtained were from three cases of CCC and one case of YST who underwent imprint smear or similar examinations. Seventeen cases of CCC and two of YST with positive cytology results, mainly obtained from ascites samples, were also examined. Cytological characteristics of CCC compared to those of YST were: more marked cohesiveness of tumor cells with less-marked pleomorphism, well-preserved cell borders, fine vesicular cytoplasm, evenly thickened nuclear membrane, and fewer nucleoli and multinucleated giant cells in number. Cells with large cytoplasmic vacuolation were infrequent, and hobnail-shaped tumor cells were rather few in number in CCC cases examined. On the other hand, in the case of YST, cells were more dyscohesive, with marked cellular pleomorphism, usually faint cell borders, no thickening of nuclear membrane and occasional presence of nuclear grooves. The "naked" cells were commonly observed. Further, nucleoli were frequently numerous in number, and multinucleated giant cells were frequently found which showed marked cellular and nuclear atypism. These characteristics found mainly in imprint smears were also relatively well preserved in specimens obtained from ascites or other metastatic sites. These findings indicate that detailed cytological examination can provide a means for differential diagnosis of CCC and YST, supplementing other clinical information.     

Use of post-column fluorescence derivatization to develop a liquid chromatographic assay for ranitidine and its metabolites in biological fluids

OBJECTIVE: To describe the cytologic features of solid and cystic tumor of the pancreas. STUDY DESIGN: Cytologic features of four cases of solid and cystic tumor of the pancreas (SCT) were reported and compared with those of three cases of islet cell tumor of the pancreas. RESULTS: Aspiration and imprint cytology of the tumor cells obtained from three cases of SCT showed papillary structures or rosette formations in part and demonstrated uniformly round to oval nuclei that contained finely granular chromatin, a fairly distinct nucleolus and a scant to moderate amount of granular or vesicular cytoplasm. Another case of SCT consisted of multinucleated giant cells with coherent chromatin as well as mononuclear cells with nuclear grooves. Islet cell tumor consisted mainly of clustered or isolated uniform mononuclear cells with rosette formations but without a papillary structure and occasional multinucleated giant cells in all cases. The nuclei of islet cell tumors had peculiar, fine chromatin aggregates with a "salt-and-pepper" appearance and slightly enlarged nucleoli. CONCLUSION: SCT is cytologically distinguishable from islet cell tumor in spite of having many cytologic features in common with it.     

Giant cell tumor of bone: frequent actin immunoreactivity in stromal tumor cells

Although giant cell tumor (GCT) of bone is a well-recognized neoplasm with distinctive clinical and histopathological features, the origin of tumor cells, particularly of mononuclear cells, has not yet been established. An immunohistochemical study was carried out on 11 cases of GCT of bone to examine the cellular natures of stromal mononuclear cells. In all cases, stromal cells were positive for muscle actin (HHF35) or alpha-smooth muscle actin, and in eight of 11 cases, positivity was intense and extensive. The cell margin of osteoclast-like giant cells (OGC) was stained positively by muscle actin, in addition to intense and diffuse positive staining of the cytoplasm for KP1 (CD68), whereas alpha-smooth muscle actin exhibited a negative reaction on the OGC. In conclusion, the tumor cells with muscle actin and alpha-smooth muscle actin positivities are not rare but frequently numerous in the GCT of bone; whereas further observation is necessary to elucidate whether the stromal cells exhibit myofibroblastic cell differentiation exactly.     

Eutocic delivery

BACKGROUND AND METHODS: Because the use of immunohistochemistry in the diagnosis of granulosa cell tumor (GCT) has not been fully explored, routinely processed (formalin-fixed, paraffin-embedded) tissue from 11 GCT, adult type, was investigated immunohistochemically (ABC method) with a broad spectrum of antibodies against various markers, including p53 and Ki-67. All of the tumors exhibited typical morphology, were limited to the ovary (stage I), and 7 cases followed a benign clinical course. RESULTS: All the tumors exhibited strong expression of vimentin, but most other antigens (including smooth muscle actin) were expressed infrequently by a minority of tumor cells or not at all. Tumor cells in 9 GCT expressed inhibin A. All the tumors exhibited very low proliferative activity, fewer than 10% of the tumor cell nuclei being stained by the antibody MIB-1 (Ki-67 antigen). The antibody D07 revealed marked overexpression of p53 protein in only one tumor. Clinical outcome was not found to be related to immunophenotypic differences. CONCLUSIONS: The diagnosis of GCT should be based primarily on the typical morphology revealed by conventional stains, but additional immunohistochemical staining with a small panel of selected antibodies (for example, against keratin, vimentin, and inhibin A) may be helpful in a few cases. The very low proliferative activity and the lack of overexpression of p53 protein are consistent with the benign clinical behavior of the majority of GCT.     

Adrenal pheochromocytoma mimicking small cell carcinoma on fine needle aspiration biopsy. A case report

BACKGROUND: Fine needle aspiration biopsy (FNAB) is a sensitive and specific technique in the diagnosis of adrenal tumors. However, in rare cases the cytomorphologic features may mimic small cell neoplasms. CASE: A 54-year-old male presented with a history of hypertension and left flank pain of recent onset. Abdominal computed tomography (CT) showed a 4-cm mass involving the left adrenal gland. Fine needle aspiration biopsy (FNAB) showed groups of small round cells with hyperchromatic nuclei. The findings were highly suspicious for metastatic small cell carcinoma. Subsequently it was learned that the mass had been noted three years earlier on CT studies but had grown from 2.5 to 4 cm. A chest radiograph was unremarkable. The clinical findings were more in keeping with a primary adrenal tumor. Immunohistochemical staining done retrospectively on the cell block showed positive reactivity for chromogranin and neuron-specific enolase. These findings, correlated with the clinical features, were in keeping with a diagnosis of pheochromocytoma. Left adrenalectomy revealed a pheochromocytoma. CONCLUSION: Adrenal pheochromocytoma should be included in the differential diagnosis of small round cell neoplasms seen on FNAB of the adrenal gland. Immunohistochemistry and clinical findings are helpful in reaching the correct diagnosis.     

Fine-needle aspiration biopsy of synovial sarcoma. A cytomorphologic analysis of primary, recurrent, and metastatic tumors

Thirteen fine-needle aspiration specimens from 10 patients with histologically proven synovial sarcoma are described. The aspiration biopsy specimens were obtained from the primary tumor in five cases, locally recurrent tumors in four cases, pulmonary metastases in three cases, and mediastinal metastasis in one case. Patient's ages ranged from 22 years to 65 years; there were four women and six men. All cases had a confirmation biopsy and/or resection specimen that were reviewed. Histologic subtypes included monophasic fibrous (5 cases), monophasic epithelial (1 case), biphasic (3 cases), and poorly differentiated (1 case). The majority of the aspiration biopsy specimens were similar with moderate to marked smear cellularity dominated by cohesive clusters of spindle-shaped cells with ovoid, hyperchromatic nuclei and scanty tapering cytoplasm. Nucleoli were not prominent. Epithelial tumor cells with ovoid to round, mostly regular, centrally to eccentrically located nuclei, surrounded by scant to abundant cytoplasm predominated in one case (monophasic epithelial) and were admixed with spindle cells in a second (classical biphasic). Multi-nucleated tumor giant cells were not observed in any of the tumors. In biphasic synovial sarcoma, the neoplastic spindle cells are generally more numerous and frequent than the epithelial cells, making distinction from monophasic synovial sarcoma or other spindle cell soft tissue tumors difficult. Although synovial sarcoma may be diagnosed by fine-needle aspiration cytology, clinical correlation, especially in monophasic types, is necessary to minimize errors in sarcoma classification.     

ALK expression defines a distinct group of T/null lymphomas ("ALK lymphomas") with a wide morphological spectrum

The t(2;5)(p23;q35) translocation associated with CD30-positive anaplastic large cell lymphoma results in the production of a NPM-ALK chimeric protein, consisting of the N-terminal portion of the NPM protein joined to the entire cytoplasmic domain of the neural receptor tyrosine kinase ALK. The ALK gene products were identified in paraffm sections by using a new anti-ALK (cytoplasmic portion) monoclonal antibody (ALKc) that tends to react more strongly than a previously described ALK1 antibody with the nuclei of ALK-expressing tumor cells after microwave heating in 1 mmol/L ethylenediaminetetraacetic acid buffer, pH 8.0. The ALKc monoclonal antibody reacted selectively with 60% of anaplastic large cell lymphoma cases (60 of 100), which occurred mainly in the first three decades of life and consistently displayed a T/null phenotype. This group of ALK-positive tumors showed a wide morphological spectrum including cases with features of anaplastic large cell lymphoma "common" type (75%), "lymphohistiocytic" (10%), "small cell" (8.3%), "giant cell" (3.3%), and "Hodgkin's like" (3.3%). CD30-positive large anaplastic cells expressing the ALK protein both in the cytoplasm and nucleus represented the dominant tumor population in the common, Hodgkin's-like and giant cell types, but they were present at a smaller percentage (often with a perivascular distribution) also in cases with lymphohistiocytic and small cell features. In this study, the ALKc antibody also allowed us to identify small neoplastic cells (usually CD30 negative) with nucleus-restricted ALK positivity that were, by definition, more evident in the small cell variant but were also found in cases with lymphohistiocytic, common, and "Hodgkin's-like" features. These findings, which have not been previously emphasized, strongly suggest that the neoplastic lesion (the NPM-ALK gene) must be present both in the large anaplastic and small tumor cells, and that ALK-positive lymphomas lie on a spectrum, their position being defined by the ratio of small to large neoplastic cells. Notably, about 15% of all ALK-positive lymphomas (usually of the common or giant cell variant) showed a cytoplasm-restricted ALK positivity, which suggests that the ALK gene may have fused with a partner(s) other than NPM. From a diagnostic point of view, detection of the ALK protein was useful in distinguishing anaplastic large cell lymphoma cases of lymphohistiocytic and small cell variants from reactive conditions and other peripheral T-cell lymphoma subtypes, as well as for detecting a small number of tumor cells in lymphohemopoietic tissues. In conclusion, ALK positivity appears to define a clinicopathological entity with a T/null phenotype ("ALK lymphomas"), but one that shows a wider spectrum of morphological patterns than has been appreciated in the past.     

Soft tissue small round cell tumors: morphological parameters

Soft tissue small round cell tumors (SRCTs) comprise a heterogeneous group of neoplasms that predominate in childhood and adolescence and share similar morphological features, consisting of dense cellular proliferation of small round cells with a primitive appearance. Rhabdomyosarcomas, peripheral neuroepitheliomas, Ewing's sarcomas, and lymphomas/leukemias are the prototypic SRCT; other recently described tumors that should be added to the list are the desmoplastic SRCT and the rhabdoid tumor of soft tissues. In addition, several other primary soft tissue neoplasms and metastatic tumors have occasionally been considered in the differential diagnosis of SRCT. The precise identification of a given SRCT is important because of its clinical relevance. However, it may be difficult because the diagnostic criteria are sometimes subtle and several histologic and immunohistochemical features are not specific and/or may be simulated by different tumor types. We discuss the morphological clues that in our opinion are most useful for their diagnosis, the criteria for distinguishing between peripheral neuroepithelioma and Ewing's sarcoma, and the main diagnostic pitfalls.     

Children with anogenital symptoms and signs referred for sexual abuse evaluations

Germ cell tumors (GCTs) are the most frequent cancer in men aged 15 to 34 years. These tumors are highly responsive to therapy with platinum-containing regimens, and 80% of cases so treated can be considered cured. Cytogenetically, 80% of GCTs have an i(12p) regardless of tumor site or histopathology, and those that are i(12p) negative have other manifestations of 12p amplification. GCTs occasionally arise extragonadally, and such cases can be especially difficult to distinguish from poorly differentiated somatic carcinomas, a situation that poses a diagnostic and treatment dilemma We developed a technique for two-color fluorescence in situ hybridization chromosome painting on nuclei released from paraffin-embedded sections. In four tumors for which GCT was a differential diagnosis, we examined the 12p and 12q chromosome arm distributions by this technique. By use of 12p and 12q painting probes developed by microdissection, 12p and 12q were distinguished and their relative distributions evaluated. In each of the four cases, 12p regions seemed to be rearranged and over-represented relative to 12q regions. In three of the cases, an apparent i(12p) could be identified. These results support a diagnosis of GCT or GCT origin in these four cases. In tumors for which specific cytogenetic abnormalities are known, chromosome painting by fluorescence in situ hybridization using paraffin-embedded tissue is a useful technique to aid in the diagnosis of tumors that are difficult to differentiate. The patients can then be placed on treatment regimens appropriate for their specific tumor type.     

Fine needle aspiration diagnosis of aggressive giant cell tumor of bone. A case report

Giant cell tumors of bone are neoplasms with potential local and systemic aggressiveness. A case of giant cell tumor with radiologic and histologic features suggestive of locally aggressive behavior is reported. Cytologic material was obtained by fine needle aspiration from an intraosseous tumor that destroyed the cortex and from the invaded, adjacent soft tissues. The smears from the osseous aspirate showed the typical cytologic features of giant cell tumor, whereas the invaded tissues had a prominent loss of cohesiveness between mononucleate and giant cells. In addition, mitotic figures in the mononucleate component were noticeable. The differential diagnosis based on clinical and cytologic findings is discussed.     

Perineurial abnormalities in the spontaneously diabetic dog

OBJECTIVE: The authors describe the salient clinical, radiologic, and histopathologic features of an orbital primitive neuroectodermal tumor in a 28-year-old man. This is an extremely rare tumor of the orbit, previously reported exclusively in children. DESIGN: Case report. INTERVENTION: Excisional biopsy of the tumor en bloc was performed. MAIN OUTCOME MEASURES: Histopathologic examination was performed by standard techniques and immunohistochemical stains on formaldehyde-fixed, paraffin-embedded tumor tissues. RESULTS: Histologic examination of the sections of the tumor showed small, blue, round cells with occasional Homer-Wright rosette formations. The tumor cells stained positively with neuron-specific enolase and vimentin. CONCLUSIONS: This newly recognized, highly unusual peripheral primitive neuroectodermal tumor should be considered in the differential diagnosis of hypercellular, small, round cell tumor of the orbit in adults.     

Malignant granular cell tumor: report of a case and review of the literature

The histological, immunohistochemical and electron microscopic features of a rare malignant granular cell tumor (GCT) arising in the left radial nerve of a 54-year-old man are reported. Despite a lack of local recurrence following extirpation, the tumor metastasized to the skull five years later. Light-microscopically, both primary and metastatic tumors consisted of markedly atypical or pleomorphic neoplastic cells with abundant cytoplasm containing diastase-resistant periodic acid Schiff reaction-positive granules. These tumor cells were arranged in a sheet-like pattern with mitotic figures including atypical ones, and were frequently immunopositive for proliferating cell nuclear antigen and c-MET, the c-met proto-oncogene product. These findings reflect high-grade malignancy of the present tumor. In addition, the tumor cells were positive for S-100 protein and neuron-specific enolase. Ultrastructurally, a large number of intracytoplasmic granules featuring secondary lysosomes as well as long interdigitating cytoplasmic processes, intercellular intermediate junctions, discontinuous basal lamina-like structures, and stromal long-spacing collagen were observed. These findings indicated schwannian differentiation of the present tumor. In addition, based on a review of previously reported cases, the overall clinicopathological characteristics of malignant GCT were summarized.     

Rhabdomyoma of the tunica vaginalis of the testis: a histologic, immunohistochemical, and ultrastructural study

A case of an unusual tumor of skeletal muscle origin is described. The tumor was located in the tunica vaginalis of the testis in a 19-year-old man. Histologic examination showed a proliferation of elongated or round cells, with clearly discernible cross striations, surrounded by abundant mature connective tissue, consistent with genital rhabdomyoma. Immunohistochemical and electron microscopic features supported this diagnosis. Rhabdomyoma must be considered in the differential diagnosis of paratesticular tumors.     

Identification of alternative splicing form of Stat2

Three cases of pulmonary leiomyosarcoma were presented. The characteristic clinical features were described with review of literature. In comparison with bronchogenic carcinoma, the leiomyosarcoma has some characteristics: 1) On chest X-ray, it usually appears as a sharply demarcated, even density round mass, growing rapidly within the lung, it rarely accompanies with hilar or mediastinal lymph node metastasis. 2) The preoperative cytological or pathological diagnosis is difficult either by sputum smear or by bronchoscopic biopsy or by fine needle percutaneous aspiration biopsy. 3) Pathological differential diagnosis of leiomyosarcoma of lung from anaplastic lung cancer is difficult. In conclusion, the primary pulmonary leiomyosarcoma is a rare malignant tumor, detecting the present illness seriously, paying attention to the chest X-ray films characterize, early surgical resection is the only way to get diagnosis and effective treatment method.     

Tenosynovial giant cell tumors: evidence for a desmin-positive dendritic cell subpopulation

Diffuse tenosynovial giant cell tumor (DGCT) could present as a large intra-articular mass (pigmented villonodular synovitis, or PVNS) or as an extraarticular mass, which might be confused with a sarcoma, particularly when growth is destructive and giant cells are few. Prompted by a DGCT in which a subpopulation of cells was desmin positive and in which an erroneous diagnosis of myosarcoma was made, we analyzed the frequency of desmin, myogenin, MyoD1, and muscle-specific actin immunoreactivity in 45 well-characterized GCTs. We also analyzed a subset of these cases with antibodies to smooth muscle actin, as well as macrophage, follicular dendritic cell, extrafollicular dendritic cell, and dermal dendrocyte-associated antigens. Sections from 45 cases of formalin-fixed GCTs (22 DGCTs, 13 cases of PVNS, and 10 localized GCTs) were immunostained for desmin, myogenin, MyoD1, and muscle-specific actin. The eight cases that showed the largest number of desmin-positive cells were immunostained for smooth muscle actin, CD45, CD68, CD21, CD35, cytokeratin 8, and Factor XIIIa. Desmin-positive cells were seen in 20 (43%) of 45 cases: 10 (43%) of 22 DGCTs, 5 (38%) of 13 cases of PVNS, and 5 (50%) of 10 localized GCTs. In contrast, none were positive for any of the other muscle-associated proteins. In almost all of the cases, the desmin-positive cells were large and dendriform, with long processes that interdigitated between adjacent round cells. Desmin immunoreactivity was found in almost 50% of all GCTs, in the absence of positivity for other muscle markers. Desmin immunoreactivity in GCT seemed to be confined to a variably sized subpopulation of large dendritic cells whose exact identity remains uncertain.     

Immunohistochemical expression of p53, MDM2, Ki-67 and PCNA in central giant cell granuloma and giant cell tumor

Central giant cell granuloma (CGCG) is a reactive bone lesion that occurs mainly in the jaws. The giant cell tumour (GCT) is a benign locally aggressive neoplasm located near the articular end of tubular bones. Both lesions are characterised histologically by multinucleated giant cells in a background of ovoid to spindle-shaped mesenchymal cells. There is a basic question whether both lesions are separate entities or variants of the same disease. The study of cell cycle-associated proteins may give insights into clarifying such question. The expression of these proteins is also important to determine the cell cycle regulation in both tumours. The purpose of this study was to evaluate the immunohistochemical expression of p53, MDM2, Ki-67 and PCNA in CGCG and GCT. The results demonstrated that, despite the lack of p53 immunoreactivity, all the samples showed wide expression of MDM2. The percentage of Ki-67- and PCNA-positive cells in CGCG was statistically higher than that of GCT Our findings show that CGCG has a higher proliferative activity compared with that of the GCT. Our results also suggest that p53 inactivation by MDM2 expression may be involved in the pathogenesis of giant cell lesions of the jaws and long bones.     

Anaplastic variant of spermatocytic seminoma

Four examples of spermatocytic seminoma with a predominant anaplastic component occurred in men 33 to 43 years of age, without histories of cyptorchidism. The seminomas presented with painless testicular masses recognized 3 to 18 months before orchiectomy. Preoperative serum measurements of human chorionic gonadotropin and alpha-fetoprotein were negative. All tumors contained areas (10% to 30% of the tumor) in which the three cell types characteristic of conventional spermatocytic seminoma could be identified under light microscopy. The predominant anaplastic component also contained the three cell types, but the nuclei had prominent nucleoli with granular and filamentous chromatin. In addition, sheets of cells with vesicular nuclei and prominent nucleoli superficially resembling embryonal carcinoma were found. There were numerous large mononuclear and multinucleated giant cells with bizarre nuclei and prominent nucleoli, but no sarcomatous elements. Many normal and abnormal mitotic figures were present. Tunical and vascular invasion and extensive necrosis were constant features. Immunohistochemistry documented p53 protein overexpression in two tumors, but neoplastic cells were negative with immunostains for placenta-like alkaline phosphatase, leukocyte common antigen, neuron-specific enolase, alpha-fetoprotein, human chorionic gonadotropin, vimentin, and cytokeratins. Ultrastructural examination of the anaplastic component showed large rope-like nucleoli, but the cytoplasmic features were similar to those of conventional spermatocytic seminoma. Despite the presence of a major anaplastic component, no patient has developed metastasis. Larger series and longer follow-up are needed to understand the natural history of these neoplasms.     

Histology, immunohistochemistry, and electron microscopy of small round cell tumors of bone

Small round cell tumors (SRCTs) of the bone make up a family of primary bone sarcomas with morphologically, biologically, and clinically specific features. Among them, Ewing's sarcoma (ES) is the most common entity, but several varieties such as atypical ES, large cell ES, and ES with neuroectodermal differentiation (peripheral primitive neuroectodermal tumor of the bone or neuroepithelioma of the bone) have been identified recently. Histology and electron microscopy together with the variable expression of several epitopes (as shown by immunohistochemistry, mainly HBA/71 [Mic2 antigen]) provide the basis for characterizing the group within the context of neuroectodermal-derived neoplasms. A number of other ES-like tumors with small round cells, mimicking those previously described, have been characterized; Askin's tumor of the thoracopulmonary region will be considered as an ES similar to those already described, but within a particularly anatomic location. On the other hand, the presence of an endothelial appearance within a poorly differentiated neoplasm may be present in some ES-like SRCTs (atypical ES with endothelial features). The differential diagnosis with other sarcomas defined by small round to spindle cell contours might prove difficult. Particular attention must be paid to small cell osteosarcoma and mesenchymal chondrosarcoma. Likewise, "primitive sarcoma of bone" is considered in this study because it is a very rare neoplasm differing from the formerly discussed types; its pluripotentiality provides this tumor a blastemic character and a multiphenotypic expression. Malignant non-Hodgkin's lymphoma is an unusual presentation when primary to the bone, previous to any other anatomic location. Several subtypes have been considered within a histology that encompasses that seen in lymph nodes.