Atypical teratoid/rhabdoid tumor of the central nervous system in an 18-year-old patient.

OBJECTIVE: Atypical teratoid/rhabdoid tumors are aggressive neoplasms of the central nervous system occurring mainly in the early childhood and rarely in adults. We described a case of this tumor in an 18-year-old male patient without previous medical history. MATERIAL AND METHODS: The neoplasm was localized in the right frontotemporal area of the brain and was totally excised. The specimen was fixed in formalin and embedded in paraffin. The histological and immunohistochemical features of the neoplasm were assessed, while sequencing analysis as well as interphase fluorescence in situ hybridization (FISH) were performed. RESULTS: Histological and immunohistochemical analysis demonstrated atypical rhabdoid cells strongly and diffusely positive for EMA and Vimentin as well as focally immunoreactive for SMA and GFAP. Additionally, though no abnormalities detected in the coding sequence of the INI1 gene, interphase FISH studies were consistent with a homozygous deletion of the INI1 gene in the majority of examined nuclei. INI1 immunostaining demonstrated diffuse loss of nuclear INI1 expression in tumor cells. Taken together, the results were consistent with a diagnosis of atypical teratoid/rhabdoid tumor (ATRT). CONCLUSIONS: 26 previous cases of ATRT have been reported in adults, thus far. To our knowledge, this is the eighth case of an ATRT reported in an adult patient having genetic confirmation and the first one in which the tumor is, partly, localized in the right temporal area of the brain. This unusual presentation underlines the necessity of considering this devastating neoplasm in the differential diagnosis of malignant brain tumors of young adults.

Dystrophic neuritic processes in epileptic cortex.

Cortical dysplasia is a frequent finding in cortical resections from children with refractory epilepsy. Diagnostic criteria and a classification scheme for cortical dysplasia has been proposed, though the relationship between specific cortical dysplasia features and their causal relationship with epilepsy is poorly understood. We reviewed 28 surgical resections from children and identified a common and easily recognized feature of cortical dysplasia: maloriented, misshapen and occasionally coarse neurofilament stained process forming a dystrophic neuritic background. The dystrophic neuritic background was associated with other features of cortical dysplasia in all 28 patients with cortical dysplasia, 26 with refractory epilepsy and 2 patients with other neurologic diagnoses. In seven children with refractory epilepsy due to other pathologic diagnosis such as vascular or glial lesions, the dystrophic neuritic background was only found in one patient with a ganglioglioma and other features suggestive of an associated cortical dysplasia. Our data indicate that a dystrophic neuritic background is a common and relatively specific neuropathologic finding in cortical dysplasia.

Dysplasia: a common finding in intractable pediatric temporal lobe epilepsy.

BACKGROUND: Risk factors for temporal lobe epilepsy (TLE) include history of CNS infection, family history of epilepsy, and history of febrile convulsions (FC). Pre-existing cortical dysplasia (CD) may also predispose to refractory TLE, independent of other risk factors for epilepsy. METHODS: The authors reviewed the neuropathologic features of surgical tissue from temporal lobectomies of 33 pediatric patients with refractory TLE, with and without a history of epilepsy risk factors. RESULTS: CD was found in 64% (21/33) of all patients with refractory TLE, including 73% (11/15) patients with a history of FC, 66% (2/3) patients with CNS infections, and 83% (5/6) patients with a family history of epilepsy. Disrupted cortical lamination, dystrophic and maloriented neurons, and balloon cells characterized the CD found in the temporal neocortex. CONCLUSION: CD was seen in 21 of 33 surgical specimens from children with refractory TLE, including those with and without other epilepsy risk factors.

Utility of immunohistochemistry in the evaluation of necrotic thyroid tumors.

We have previously shown that necrotic tumors retain their immunoreactivity for a range of cytokeratin antibodies. Some thyroid tumors undergo extensive necrosis after fine-needle aspiration (FNA) procedures. We evaluated the sensitivity of antibodies on necrotic thyroid tumors by examining a series of thyroid tumors consisting of 10 Hurthle cell neoplasms, 8 carcinomas, and 2 follicular adenomas (12 with post-FNA necrosis). These were stained with antibodies to AE1/3, PANCK, thyroglobulin and S100. Four of the cases of papillary carcinoma were also stained with antibodies to CK19. As a control for the specificity of thyroglobulin immunoreactivity in necrotic tissue, we also stained 11 nonthyroid tumors with extensive necrosis (7 carcinomas, 1 lymphoma, 2 melanomas, 1 sarcoma) for thyroglobulin. Six of 8 thyroid carcinomas were positive for AE1/3 and PANCK; AE1/3 reactivity was retained in necrotic areas of 4 of 6. AE 1/3 was positive in necrotic portions of 5 of 10 Hurthle cell lesions, whereas PANCKwas negative in all but 1. Thyroglobulin reactivity was present in 18 of 20 cases, and was preserved in necrotic portions of 5 of 6 carcinomas, as well as 8 of 10 Hurthle cell neoplasms. S100 cytoplasmic reactivity was present in 4 Hurthle cell neoplasms and 1 papillary carcinoma; this staining was lost in necrotic areas. No staining by thyroglobulin was observed in the viable or necrotic areas of nonthyroid neoplasms. The preservation of cytokeratin reactivity, measured by AE1/3, in thyroid neoplasms is a diagnostically useful feature in spontaneous and post-FNA infarction. PANCK is not a well-preserved marker in necrotic thyroid tissue. This difference may be due to detection of keratin 19 by AE1/3. Thyroglobulin is preserved in some necrotic thyroid carcinomas and in Hurthle cell lesions. Preservation of thyroglobulin reactivity in necrotic tissue is specific in that no staining was observed in nonthyroid neoplasms. These results suggest that thyroglobulin is useful in demonstrating thyroid lineage of both primary and metastatic necrotic tumor masses.

Neurosarcoidosis presenting in the pituitary gland with normal endocrine studies.

Two cases of neurosarcoidosis in the pituitary gland are presented with a review of past cases from the literature. Previous reported cases have always shown changes on the ondocrine exis clinically. These two cases, however, were endocrinologically normal prior to surgery. The evaluation of neurosarcoid in the pituitary, clinically and radiographically, is discussed.

Sensitivity and specificity of antibodies on necrotic tumor tissue.

Immunohistochemistry occasionally is used to determine the lineage of entirely necrotic tumors. However, the sensitivity and specificity of antibodies on necrotic tissue are unknown. To determine the usefulness of immunohistochemistry with necrotic lesions, a series of 24 known tumors consisting of 14 carcinomas, 2 lymphomas, 2 melanomas, and 6 sarcomas (all with extensive necrosis) was examined for reactivity with 6 cytokeratin antibodies, S100, and LCA. Carcinomas stained positively with at least 1 cytokeratin antibody in 78% of the cases. The cytokeratin antibodies with the highest sensitivity were AE1, AE1/3, S903, and PANCK. These antibodies also retained specificity for epithelial differentiation; no reactivity was observed in the 10 necrotic nonepithelial tumors. LCA retained its reactivity with necrotic lymphoma, but S100 reacted with only one third of the necrotic lesions. Unexpectedly, reactivity for LCA and S100 occurred in some necrotic carcinomas. Keratin markers can be used on necrotic tissue to determine epithelial differentiation, but the results obtained with S100 and LCA on necrotic tissue should be interpreted with caution.

Granular histiocytosis of pelvic lymph nodes following total hip arthroplasty. The presence of wear debris, cytokine production, and immunologically activated macrophages.

UNLABELLED: Infiltration of regional lymph nodes by macrophages has been demonstrated after total joint arthroplasty. Although lymph nodes regulate the immune response, neither cytokine production nor the degree of immunological activation of cells within these nodes after total joint arthroplasty has been investigated. Pelvic lymph nodes were obtained from five patients who had had a total of eleven arthroplasties in seven hips three to twenty years before a pelvic staging procedure for adenocarcinoma (of the prostate in four patients and of the endometrium in one). All lymph nodes had polyethylene or metal debris as well as effacement of the normal nodal architecture by a histiocytic infiltrate. These changes were bilateral in the patients who had had an arthroplasty of one hip. Analysis of specimens from pelvic lymph nodes on the side of the involved hip demonstrated intense immunohistochemical staining of histiocytes for the major histocompatibility complex class-II antigen HLA-DR, a marker of histiocyte immune activation. In contrast, staining was absent in specimens from the contralateral lymph nodes as well as in those from seven patients who had had a prostatectomy but not a hip arthroplasty. Immunohistochemical staining for interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6 demonstrated a much greater expression of these cytokines in the involved lymph nodes. CLINICAL RELEVANCE: Additions improvements in total joint replacement will be facilitated by a more thorough understanding of the biological response to the components and materials of implants. While local biological factors leading to failure of prostheses are currently under intense investigation, the mechanisms and importance of regional and systemic immune responses to wear debris require further study.

Primary lymphoma of bone. Correlation of magnetic resonance imaging features with cytokine production by tumor cells.

BACKGROUND: Primary lymphoma of bone is a rare, aggressive neoplasm that can present with a large, soft-tissue mass despite minimal evidence of cortical destruction on plain radiographs. METHODS: High resolution magnetic resonance imaging (MRI) examinations of four patients with primary lymphoma of bone were reviewed retrospectively, and in each case intramedullary tumors demonstrated "penetrating channels" extending through the cortex. The MRI studies were correlated with the histopathologic assessment of the tumor for each patient. Immunohistochemistry was performed for immunophenotyping and for cytokine expression by tumor cells. The cytokines that were investigated were interleukin-1, interleukin-6, and tumor necrosis factor-alpha, molecules known to regulate osteoclastic activity. RESULTS: The linear cortical foci noted on MRI correlated with the histopathologic findings of tumor-associated cutting cones, in proximity to osteoclastic bone resorption. Immunohistochemical stains showed a B-cell phenotype for each tumor and positive immunoreactivity in tumor cells for cytokine mediators that stimulate osteoclastic activation. CONCLUSIONS: These findings indicate that the tumor cells in these cases produce soluble cytokine mediators that may regulate extensive osteoclastic activity. In primary lymphoma of bone, tumor activation of osteoclastic resorption, with production of tumor tunnels through the cortex, may represent one of the mechanisms by which lymphoma escapes the intramedullary space and forms large, soft-tissue masses without extensive cortical destruction.