Petroclival intravascular papillary endothelial hyperplasia with psammoma body-like structures.

Masson's tumor or intravascular papillary endothelial hyperplasia (IPEH) is considered a non-neoplastic lesion. It is probably an unusual exaggerated reorganization of a thrombus. IPEH may be present as a secondary lesion in hemangiomas. Symptomatic osseous hemangiomas are rare tumors. Few cases of clival and petrous bone hemangiomas have been described. None of them shows secondary IPEH. So far, there are only four reported cases of cranial bone IPEHs in the literature, two in the skull, one in the clivus and one in the petrous apex. The aim of this study is to report an additional case of osseous hemangioma with secondary IPEH of the petroclival region. We review the literature and describe the main clinical features of IPEHs and hemangiomas of the clivus and the petrous bone. Additionally, we report an unusual histological feature observed in our case of IPEH, the presence of psammoma body-like structures. This feature has been rarely mentioned previously in IPEH. We consider that IPEH should be included in the lesions that may present psammoma bodies to avoid misdiagnosing it as a tumor that commonly shows psammoma bodies, such as intraosseous meningioma or, less frequently, metastasis of thyroid or ovarian carcinoma.

Histopathological features of malignant craniopharyngioma: Case report and literature review.

Malignant transformation in craniopharyngiomas is a very uncommon event and scarcely mentioned in the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS). So far, there are only 34 reported cases. AIMS: We report an additional case in a 63-year-old woman who was diagnosed with craniopharyngioma 47 years ago. We reviewed the literature in order to define the histological features of malignant craniopharyngioma and its overlap with odontogenic tumors. RESULTS: Our case presented morphology of mixed odontogenic ghost cell/ameloblastic carcinoma. Analyzing all reported cases, 18 of them presented malignization as squamous cell carcinoma (SCC), 1 as odontogenic ghost cell carcinoma, 2 as ameloblastic carcinoma, and 10 cases were mentioned just as malignant craniopharyngiomas. CONCLUSION: We concluded that SCC represented only half of the malignant cases, while the morphology of ~ 11% of them was comparable with ameloblastic or odontogenic ghost cell carcinomas and 28% lacked a specific histological diagnosis. Most cases were fatal, which makes it necessary to include the entity of malignant craniopharyngioma in the WHO Classification of Tumors of the CNS as a high-grade tumor defining its histological variability.

Report of a case of giant cell ependymoma with unusual clinical and pathological presentation.

Giant cell ependymoma (GCE) is a very uncommon variant of ependymoma, known for having varying degrees of nuclear pleomorphism. There are only 34 reported cases of GCE in the English literature. We describe an additional case of a young woman who presented with a tumor located in sacral soft tissue, which was not connected to the spinal cord and did not show additional lesions in the central nervous system. Complete tumor resection was performed and no recurrences or metastasis were detected after 5 months of follow-up. Only one of all the reported GCE was located in the sacral subcutaneous region, where ependymomas are rarely found and usually have myxopapillary histology. Ours is the second report showing microscopic features of GCE in the soft-tissue region. GCE should be considered in the differential diagnosis of lumbosacral subcutaneous tumors to avoid misdiagnosing it as a malignant lesion. Since GCE could be an extraspinal extension of an intraneural ependymoma, it would be important to evaluate whether it is connected to the spinal cord.

Immunohistochemical Expression of Progesterone Receptors in Nonmeningothelial Central Nervous System Tumors.

INTRODUCTION: Immunostaining of progesterone receptors (PRs) has been described as a prognostic factor related to recurrences in meningiomas. However, its expression in other primary intracranial tumors has been poorly studied. In this paper, we compare the pattern of expression of the receptor in meningiomas with that of nonmeningothelial intracranial tumors to evaluate its value in the diagnosis of the former. MATERIALS AND METHODS: A total of 42 nonmeningothelial intracranial tumors (21 glioblastomas, 4 anaplastic oligodendrogliomas, 4 oligodendrogliomas, 1 pilomyxoid astrocytoma, 3 ependymomas, 8 schwannomas, 1 chordoid chordoma) and 32 meningiomas (1 rhabdoid, 1 papillary, 5 atypical, 7 with histologic features of more aggressive behavior, 1 microcyst, 8 meningothelial, 7 transitional, 2 fibroblastic) were studied for PR by immunohistochemistry. RESULTS: About 73.8% of the nonmeningothelial tumors and 100% of the meningiomas were positive for the receptor, the difference being statistically significant (P=0.0017). The mean percentage of positive tumor cells per high-power field was frequently higher than 30% in meningiomas and lower than 10% in nonmeningothelial tumors (P=0.0001). CONCLUSIONS: Although we detected that immunostaining for the PR is more frequently observed in meningiomas, we confirmed its expression in diverse nonmeningothelial primary intracranial tumors. Immunohistochemistry for PR would be useful in the diagnosis of meningioma only when its positivity shows a mean higher than 30% of the positive tumor cells per high-power field.

Main steps of skeletal muscle development in the human: morphological analysis and ultrastructural characteristics of developing human muscle.

During embryogenesis, paraxial mesoderm undergoes segmentation into somites, progressing from head to tail. Somites differentiate into dermomyotomes, then into dermatomes and myotomes. Some head muscles derive from the anterior paraxial and precordal mesoderm. Between 10 and 13 weeks of gestation, the fusion of myoblasts generates primary myotubes with central nuclei, and the latter form the second generation of myotubes which requires active innervation. Nicotinamide adenine dinucleotide dehydrogenase-tetrazolium reductase appears before succinate dehydrogenase, and ATPase shows an intermediary activity. ß-Sarcoglycan appears by 7 gestational weeks and α-sarcoglycan by 10-12 weeks. ß-Spectrin, dystrophin, and utrophin appear by 9 weeks, vimentin and desmin appear by 10 weeks and stain strongly between 10 and 15 weeks. Slow, embryonic myosin heavy chain (MHC) isoenzymes appear before 15 weeks, whereas fetal fast MCH occur later (15-18 weeks). Myotubes become myofibers with peripheral nuclei between 15 and 18 weeks. Large muscle fibers (Wohlfart B) are visible by 20-21 weeks, Wohlfart A by 21-25 weeks. Perimysium surrounds compacted and grouped fibers by 24 weeks, and utrophin disappears, whereas dystrophin stains intensely. At 29 weeks, type I fibers are visible, and by 31-33 weeks they are mature for ATPase staining. Three types of type II fibers can be seen. Vimentin disappears between 15 and 30 weeks, while desmin remains weakly positive at birth.

Telethonin-deficiency initially presenting as a congenital muscular dystrophy.

Congenital muscular dystrophies are defined by congenital or infantile onset of muscle weakness; while 12 culprit genes have been identified, many cases remain molecularly uncharacterized. On the other hand, mutations in the telethonin gene (TCAP) have been associated with a rare form of recessive limb girdle muscular dystrophy, usually presenting in the second decade. So far, three different mutations in telethonin have been reported in patients suffering from limb muscular dystrophy type 2G. We have identified a novel telethonin mutation in a child presenting with mildly delayed motor development and muscle weakness from infancy, clinically improving over the first decade, indicative of a CMD. Muscle biopsy showed a dystrophic process, with preserved laminin α2, collagen VI, and α-dystroglycan, but absent telethonin immunolabeling. Sequence analysis of TCAP showed a novel non-sense p.Gln58X (c.172C>T) homozygous mutation. Our observation indicates that telethonin deficiency may present in infancy with clinical features overlapping with mild forms of α-dystroglycanopathy. Therefore telethonin analysis should be performed in patients suffering from congenital muscular dystrophy of unknown cause.