Osteoclastoma of occipital bone

Osteoclastoma of the calvarial bone of membranous origin is a rare entity. This paper presents a case of osteoclastoma of the occipital bone and a brief review of literature.     

关于枕鳞的顶间部骨化中心及顶间骨来源的研究

枕鳞的顶间部为膜化骨,其骨化中心共六对,排列成上、中、下三列。上列为左、右各一个骨化中心,能转化为前顶间骨;中列分内、外两对骨化中心,能转化为顶间骨;下列为三对骨化中心。在中列骨化中心和下列骨化中心之间为枕横缝出现的部位。     

Chiari malformation with thick occipital bone

A case of a Chiari malformation with an extraordinarily thick occipital bone is described. The thick occipital bone might make the posterior fossa narrow with consequent herniation of the cerebellar tonsils to the foramen magnum and formation of a syrinx. At dural plasty, well-developed marginal and occipital sinuses should be deliberately handled with the preservation of normal venous drainage. This case gives us the essence of the occurrence mechanisms of Chiari malformation and foramen magnum decompression.     

Triplication of the lesser occipital nerve

Triplication of the lesser occipital nerve (LON) was observed bilaterally in an adult male cadaver during routine prosection of the posterior triangle. The three LONs were studied to determine the clinical importance of this variation. The origin of one LON was from a nerve to the trapezius that had a common origin with the trunk of the supraclavicular nerve (C3,4) from the cervical plexus. Such a common origin of a LON may explain the pain referred to the shoulder and arm that is experienced by some patients with cervicogenic headache. Another LON ran across the roof of the posterior triangle, passed through the trapezius and was closely related to the point of exit of the greater occipital nerve (GON) from the trapezius. This LON supplied the nape of the neck, back of the scalp and the auricle. The anomalous course taken by this LON through the trapezius may be an explanation for cervicogenic headache precipitated by neck movement. The close relationship of this variant LON to the exit of the GON from the trapezius seems to be relevant to the management of cervicogenic headache. The authors suggest that the reason for the complete pain relief experienced by some patients with cervicogenic headache by anesthetic blockade of the GON may be because both the GON and LON are blocked simultaneously due to their proximity in these patients.     

Endolymphatic sac tumor: a rare tumor of internal ear. Report of two cases

Papillary tumors of the temporal bone are rare and aggressive neoplasms. Recently described, these tumors had initially a presumed middle-ear origin. Only recently, convincing anatomic, morphological and immunohistochemical arguments exist for an endolymphatic sac origin (inner-ear origin). We report two cases of endolymphatic sac tumor. These tumors can be encountered sporadically or in Von Hippel-Lindau disease. They classically grow very slowly, resulting in late clinical manifestations with expansive mass invading temporal bone and extending in posterior fossa. Radiologically, these endolymphatic sac tumors can mimic metastatic carcinoma, paraganglioma, or cerebellar haemangioblastoma specially in von Hippel-Lindau disease. Histology shows a papillary epithelial tumor with hypervascular stroma, without atypia. The treatment for these tumors is surgical and curative when early diagnosed. In apparently sporadic cases, genetic analysis for Von Hippel-Lindau disease should be considered.     

The cutaneous cervical plexus nerves of the crab-eating macaque (Macaca fascicularis), eastern grey kangaroo (Macropus giganteus), and koala (Phascolarctos cinereus)

The origin, course and distribution of the cutaneous nerves of the cervical plexus were examined in the crab-eating macaque (4 body-halves), the grey kangaroo (5 body-halves) and koala (3 body-halves). The cutaneous nerves, n. auricularis magnus, nn. supraclaviculares, n. transversus colli, and n. transversus cervicis, were recognized. Cranial and caudal branches were identified in the latter 2 nerves. Some intermediate, relatively small branches were recognized between these main nerves. The n. occipitalis minor was not recognized in all our specimens. Four segmental nerves, C2 to C5, gave rise to all the cutaneous nerves and branches of the cervical plexus described. However, between species there was some variation. In the crab-eating macaque the n. auricularis magnus and n. transversus colli tended to arise from a lower segment than in the grey kangaroo and koala. In the grey kangaroo the nn. supraclaviculares arose from a lower segment than in the crab-eating macaque and koala.     

Median (third) occipital condyle

Abnormalities of the craniovertebral junction, most of which are associated with the occipital bone, are of interest not only to anatomists but also to clinicians because many of these deformities produce clinical symptoms. The occipital bone in humans is formed by the fusion of the sclerotomes corresponding to the roots of the hypoglossal nerve. In lower vertebrates, the cranial half of the first cervical sclerotome forms a separate bone between the atlas and occipital bone, the proatlas; in man it may contribute to anomalous structures around the foramen magnum. One such structure, a median occipital condyle, which exhibited an articular facet for the odontoid process, was observed in an adult male skull at the anterior margin of the foramen magnum. This anomaly is discussed in light of available literature.     

Ein Knochentumor an einem prÄkolumbischen IndianerschÄdel aus Peru

Zusammenfassung Es wird ein etwa kleinwalnu\gro\er gestielter knöcherner Tumor im Bereich der Protuberantia occipitalis externa eines prÄkolumbischen PeruanerschÄdels beschrieben. Mit Hilfe röntgenologischer und histologischer Untersuchungen lÄ\t sich die Geschwulst in die Gruppe der fibroossÄren Tumoren einordnen. Differentialdiagnostisch handelt es sich um die selten vorkommende eburneisierte Form der gro\en vorwiegend spongiösen Osteome des SchÄdeldachs.

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An osseus tumor in the skull of a precolumbian Indian from Peru

Summary A walnut-sized, stalked, osseus tumor in the region of the protuberantia occipitalis externa of the skull of a precolumbian Indian from Peru is described. Radiological and histological examinations grouped this neoplasm with the fibro-osseus tumors. Cytologically, it is one of the rarely seen nearly compact forms of the large, mostly spongy osteomas of the skull roof.

     

The Ligamentum condylicum posterius as a precursor structure of the Processus condylicus posterior,another Proatlas-Manifestation of the human occipital bone

This article presents the results of a dissection series investigating a previously neglected ligamentous structure attached to the human occipital bone, the Ligamentum condylicum posterius or posterior condylar ligament, and relates these results to the manifestation of a likewise poorly recognized occipital bony variation, the Processus condylicus posterior. The dissection of 50 human cranio-cervical junctions revealed the existence of the posterior condylar ligament in 98% of all cases, sometimes containing free elongated ossicles and osseous spurs at the insertion points at the occipital bone. In two cases the osseous formation of a Processus condylicus posterior became apparent (4%), which further provided the opportunity to study the behaviour of the ligament in these cases. In this article, we show and discuss that the posterior condylar ligament and osseous structures possibly derive from tissue that originates from the material of the dorsal arch of the Proatlas, a rudimentary vertebra between occipital bone and atlas. For this purpose, the Ponticulus atlantis posterior as another Proatlas-manifestation, whose origin from the dorsal Proatlas-arch is widely accepted in literature, is considered. This bony variant was found in 11 specimens (22%) in the present study and further served to classify and interpret the findings of the much rarer Processus condylicus posterior. As a result of this dissection series and a review of literature on this understudied topic, a typology of manifestations of the posterior condylar ligament, Processus condylicus posterior and related structures like free ossicles has been introduced.     

Biopsy specimen identification by detection of sex chromosomes: application of in situ hybridisation.

AIMS: To investigate the feasibility of non-radioactive in situ hybridisation (ISH) for the identification of sex-mismatched plastic embedded bone marrow biopsy specimens. METHODS: After a suspected accidental transposition of two glycol-methacrylate embedded bone marrow specimens, in situ hybridisation with sex chromosome specific probes was performed. RESULTS: Quantitative analysis of the hybridisation signals established unequivocably the origin of the specimens. CONCLUSIONS: ISH is feasible on GMA embedded bone marrow specimens, and can be used for the identification of accidentally transposed specimens provided that they are of sex-matched origin.     

Surface bone histology of the occipital bone in humans and chimpanzees

Human and chimpanzee occipital bones are thought to grow and develop in distinctly opposite bone remodeling patterns. Preliminary research examining growth-remodeling fields (GRFs) from the surfaces of the occipital bone in modern humans and chimpanzee indicates this may not be entirely correct. By using vinyl/resin-casting techniques, coupled with scanning electron and reflected-light microscopy, GRF profiles from a cross-sectional sample of humans and chimpanzees have documented the ongoing histological activities that reflect developmental processes through which taxon-specific ontogenetic trajectories alter bone morphology. Surface bone profiles aid in explaining how the posterior skull takes shape, thereby aiding in our understanding of the developmental processes that may contribute to the morphological variation in the posterior skull in humans and chimpanzees.     

Induction of PHA response in mouse bone marrow cells by thymic extracts as studied by changes in the structuredness of cytoplasmic matrix.

The specificity and cross-species activity of thymic extracts and some non-specific agents on some alleged properties of T cells and their precursors in the bone marrow cells of normal, nude and thymectomized mice was studied in vitro. The phenomenon of changes in the structuredness of cytoplasmic matrix (SCM) was used to assess the maturation and responses of cells treated with the extracts to mitogens, i.e. phytohaemagglutinin and concanavalin A. We found that thymic extracts of calf and mouse origin induce functional 'maturation' which can be abrogated by cycloheximide, an inhibitor of protein synthesis. The nonspecific agents used (spleen extracts, PPD, dBcAMP and endotoxin) had no effect on bone marrow cells, as measured by changes in the SCM. The method of measuring SCM using the technique of fluorescence polarization is described.     

The role of a parathyroid hormone analogue in the pathogenesis of malignant hypercalcemia

Patients with malignant hypercalcemia can display not only an increase in bone resorption, but also changes in the renal tubular reabsorption of calcium and phosphate similar to those found in primary hyperparathyroidism. A protein of tumoral origin likely responsible for this syndrome has been described. Even if produced by another gene than parathyroid hormone, it shares a homology in the aminoterminus and seems to exert a similar spectrum of action. Besides its role in malignant hypercalcemia, this analogue may be involved in physiological regulatory processes.     

Emissary occipital foramen

214 skulls were studied for the present study. A small foramen in the squamous part of the occipital bone just behind foramen magnum was noticed for the passage of emissary vein in one skull only, probably connecting occipital sinus with suboccipital venous plexus.     

The bone marrow constitutes a reservoir of pericyte progenitors

Adult bone marrow is a rich reservoir of hematopoietic and mesenchymal stem and progenitor cells. Mobilization and recruitment of bone marrow-derived cells to injured or ischemic tissue or tumors endorse the initiation and maintenance of angiogenic processes in the adult by incorporating endothelial progenitor cells (EPC) into the developing vasculature and by recruiting accessory hematopoietic cells. Recent data have now revealed that the origin of bone marrow-derived vascular cells is not restricted to endothelial cells but also includes pericytes--the perivascular support cells. Several laboratories have now reported the existence of pericyte progenitor cells, and these cells, like EPC, can be mobilized and recruited to the remodeling vasculature under ischemic conditions and in tumors. This review focuses on pericytes in vessel formation and on recent discoveries about their bone marrow origin in the adult.     

Fatal dissemination of cytomegalovirus after bone marrow transplantation

The clinical course and necropsy findings are described of an 11-year-old child found to have active cytomegalovirus infection at the time of bone marrow transplantation for acute lymphoblastic leukaemia. Attention is drawn to the presence of primitive mononuclear cells of uncertain origin in the regenerating bone marrow.     

Canine bone marrow cytology as a means of supporting peripheral blood changes

The origin of induced changes in the peripheral blood frequently resides in the bone marrow. Although interim (within study) canine bone marrow analysis provides crucial and vital information supplementary to such changes, it is not a routine technique in normal toxicity studies. A two-tiered approach is reasonable and scientifically justified, with haemocytometry as the first tier, and interim bone marrow analysis as the second, only to be performed if indicated by peripheral blood values.Additionally, ethical and economic reasons play a decisive role in not performing interim canine marrow sampling on a routine basis, but only on selected occasions. Such an occasion would be the presence of a thrombocytopenia, where an objective assessment of megakaryoblast/megakaryocyte numbers and morphology would be a distinct advantage in determining the aetiology of the condition. However, such evaluations are normally hampered by the relatively small numbers of these cells, and a method for overcoming this problem is described.     

The mendosal suture of the occipital bone: occurrence in Indian population,embryology and clinical significance

The Occipital occipital bone is ontogenetically and functionally unique when compared to the other bones of the skull in humans and other mammalian cousins. The Occipital occipital bone develops from six ossification centers; any defect in the ossification process will give rise to mendosal suture (accessory suture) and conditions like posterior plagiocephaly. There is a paucity of literature regarding the mendosal suture and further more, its report in Indian population is not known. The present study was conducted to find out the occurrence of mendosal suture in the Indian dry skulls. Fifteen specimens (3%) were found to have these sutures out of five hundred500 skulls examined. Nine (3.1%) samples are of male skulls out of two hundred ninety (290) and six (2.85%) samples are that of female skulls out of two hundred ten210. The mendosal suture ran close to the superior nuchal line in all specimens and traveled medially from the lambdoidal suture. The length of the sutures ranged from 0.8 cm to 2.6 cm (1.88 cm) on the right side and 1.4 cm to 2.9 cm (1.94 cm) on the left side respectively in male skulls; and 0.7 cm to 2.8 cm (1.55 cm) on the right side and 1 cm to 2.4 cm (1.42 cm) on the left side, respectively, in female skulls. The origin of mendosal suture from the lambdoidal suture was 5.7 cm to –6.3 cm (5.98 cm) from the tip of the mastoid process on the right side and 5.6 to –6.3 cm (6 cm) on the left side, respectively, in male skulls; and 5.4 cm to –5.8 cm (5.58 cm) on the right side and 5.4 cm to –5.6 cm on the left side respectively in female skulls. The occurrence and clinical significance of the present study is discussed.     

Unusual myeloid leukaemia in patient with Hodgkin''s disease.

An unusual case of leukaemia in a patient with Hodgkin's disease is described. The leukaemic blast cell population was typified by the presence of a substantial proportion of binucleate and multinucleate cells, many of which had the morphological features of Sternberg-Reed cells. The circulating and bone marrow blast cells were shown by immunophenotyping to be of myeloid origin.     

Generation of natural killer cells from bone marrow precursors in vitro.

A simple and highly reproducible bone marrow culture system for the generation of cytolytically active NK cells from immature precursors in the bone marrow is described. The NK cells can be generated with various sources of IL-2, including Con A-conditioned medium, supernatants from IL-2-producing cell lines and recombinant IL-2. Neither IL-1, IL-3 nor alpha/beta interferon induced significant cytotoxicity in bone marrow cells. Identification of the cytotoxic cells as NK cells was based on their phenotypic characteristics (aGM1+, Thy 1 +/-, Ly 1-2- X Ia-, RIL-2 +/-, H2+), as well as their spectrum of target specificity. The deliberate addition of peripheral blood mononuclear cells as a source of mature NK cells and elimination of cells expressing markers specific for mature NK cells indicated that the generated NK cells were descendants of precursors of NK cells harboured in the bone marrow and not derived from mature NK cells contaminating the bone marrow preparations. Thus, it was shown that not only functionally active NK cells but also their precursors are highly dependent on IL-2 for differentiation and growth. This culture system should be helpful in studying the origin of NK cells in relation to other cell lineages as well as the regulation of the maturation of NK cells from their precursors.