Reactive alveolar epithelium in chondroid hamartoma of the lung

OBJECTIVE: To determine the morphologic characteristics of the nonciliated epithelium found in chondroid hamartoma of the lung. STUDY DESIGN: The morphologic characteristics and immunohistochemical reaction for surfactant protein A of the nonciliated epithelium in chondroid hamartoma of the lung was studied by immunohistochemistry. Alveolar epithelium in normal lung tissue and lung tissue surrounding primary lung cancer or metastatic lung lesions was used as a control. RESULTS: In all cases, the nonciliated epithelium in chondroid hamartoma showed the morphologic criteria of hyperplastic alveolar type II cells and a very strong positive surfactant protein A reaction in the cytoplasm when compared with alveolar epithelium of the normal lung. Similar hyperplastic type II cells were also found in the alveolar lung around metastatic or primary lung tumors. CONCLUSION: These findings may indicate that the nonciliated cells found in chondroid hamartoma of the lung are hyperplastic type II cells. This suggests that the alveolar epithelium found in chondroid hamartoma of the lung is a secondary reaction around the hamartoma and not a primary component of the lesion.     

Retroperitoneal mesenchymal chondrosarcoma. Report of a case diagnosed by fine needle aspiration cytology

An unusual case of retroperitoneal mesenchymal chondrosarcoma diagnosed by fine needle aspiration (FNA) biopsy is described. CT-guided FNA of a mass arising in retroperitoneal soft tissues yielded an amorphous, myxoid material containing two distinct and separate populations of tumor cells. One was an undifferentiated, monomorphic, small cell component with granular cytoplasm and round central nuclei. The second population was an overtly malignant chondroid component scattered within an abundant myxoid matrix showing foamy cytoplasm, marked nuclear pleomorphism and frequent multi-nucleation. These cytologic findings were distinctive and similar to the histologic findings. The differential diagnosis and the possible pitfalls in the FNA diagnosis of this relatively rare tumor are discussed.     

A histochemical study of chondroid tissue in Limulus and Octopus

Summary In a comparative histochemical study of Octopus and Limulus chondroid tissues and mouse tracheal cartilage, it was demonstrated that both invertebrate chondroids behave as less acid mucopolysaccharides than those in mouse cartilage. Octopus chondroid was less reactive than Limulus chondroid. Cetyl pyridinium chloride blockage of toluidin blue metachramasia could be unblocked in mouse cartilage by an hour's treatment in 0.5 M KCl, but even extended periods in 2.0 M KCl failed to accomplish this in the invertebrate chondroids. With a number of methods for demonstrating proteins, Octopus chondroid was less reactive than Limulus chondroid. Limulus chondroid matrix was intensely stained by methods for demonstrating protein thiol groups, but essentially no staining was observed in Octopus chondroid matrix. These studies indicated that the composition and/or structure of matrix material in the invertebrate chondroids differ from one another, and in turn differ from conditions in vertebrate hyaline cartilage.This work was supported by a grant (HD-1499-04) and a Career Development Award (5-K3-6176-04) from the National Institute of Child Health and Human Development of the U.S. Public Health Service.A contribution of the Sea Horse Key Marine Laboratory of the University of Florida.     

Morphology and mechanics of chondroid cells from human adipose-derived Stem cells detected by atomic force microscopy

Chondroid cell from human adipose-derived stem cells (ADSCs) has emerged as an alternative treatment option for articular cartilage defects. Herein, we successfully compared ADSCs, normal chondrocytes, and chondroid cells. The comparative study of ADSCs and chondroid cells revealed type II collagen (COL II) and glycosaminoglycans expression of chondroid cells were similar to those in normal chondrocytes, and much higher than ADSCs. Using atomic force microscope (AFM) and laser confocal scanning microscopy (LCSM), we compared the differences in morphology, mechanical properties, and F-actin distribution between chondroid cells and normal chondrocytes. Our results showed no differences observed between these two types of cells regarding morphology, stiffness, and F-actin distribution. However, found that the adhesion force in chondroid cells was lower than that in normal chondrocytes. Taken together, our AFM and LCSM analyses suggest that the lower adhesion force in chondroid cells may contribute to the dedifferentiation of ADSC-derived chondroid cells. Future examination of surface adhesion force-related protein expression will likely provide new insight into the molecular mechanisms underlying the dedifferentiation of ADSC-derived chondroid cells.     

Mucosubstance histochemistry of pleomorphic adenoma of parotid and submandibular salivary glands of man: light and electron microscopy

Summary Lumina and adluminal cells in human salivary gland pleomorphic adenomas were found to contain neutral, carboxylated, and occasionally sulphated glycoproteins. A variable component of luminal contents and secretory granules did not appear to contain glycoprotein and possibly consisted of protein. Glycosaminoglycans, which appeared to be hyaluronic acid and chondroitin sulphate, were demonstrated rarely in lumina, often between epithelial cells, and forming the matrix of myxoid tissue and, together with collagen, chondroid tissue. No differences were seen between tumours from parotid glands and those from submandibular glands. Glycoproteins demonstrated in the epithelium are similar to those of intercalary ducts of parotid and submandibular glands, and may represent a primitive form of salivary secretion. Glycosaminoglycans secreted intercellularly by epithelial cells cause their increasing separation to form myxoid or chondroid tissue. This stromalization extends to lumina to produce a loss of epithelium. Pleomorphic adenoma appears to be a manifest example of variable derepression of the genotype.     

A new transplant bone for maxillary alveolar cleft

An innovative technique with distraction osteogenesis has been developed in our research group to explore autogenous bone transplantation into craniofacial bone defects. This technique was designed to investigate bone-marrow transplantion using a chondroid or fibula bone graft into simulated alveolar bone defects in mice in terms of the osteogenic process and activity. As an experimental model of maxillary alveolar bone cleft available for testing bone-inductive materials, a critical-size defect was formed in the pre-maxillary bone of male mice using a surgical trephine bur with a low-speed dental engine. Distraction osteogenesis was performed using an external fixation device. The osteotomy site was occupied by an external callus consisting of hyaline cartilage with a large quantity of chondroid bone. Moreover, bone remodelling with new bone formation was demonstrated 30 days after the transplantation. Bone adhesion was better in chondroid bone grafting than in fibula bone grafting. The present findings are the first to demonstrate the potential of chondroid bone transplantation as a new therapeutic system of bone grafting, suitable for bone substitutes in craniofacial bone defects.     

New biomaterials and methods for craniofacial bone defect: chondroid bone grafts in maxillary alveolar clefts

The purpose of this study was to evaluate autogenous osteogenic marrow within chondroid bone grafts in simulated alveolar defects of mice in order to determine the ability of the graft material to effectively close the cleft from an osseous standpoint and to observe the effect of the grafting procedure. Critical-sized defects were made in the premaxillary bones of male mice using a surgical trephine and a low-speed dental engine as a model of the maxillary alveolar cleft for testing bone-inductive agents. Premaxillary trephine defects were not repaired by fibrous tissue or bone formation 30 days after operation. This nonhealing bony wound of the premaxilla in mice may be useful as a model for studying the effect of bone-inductive agents on the healing of alveolar clefts. Distraction osteogenesis is a recently advanced principle of bone lengthening in which a long bone separated by osteotomy is subjected to slow progressive distraction using an external fixation device. The osteotomy site was surrounded by an external callus consisting of hyaline cartilage. The callus contained a lot of chondroid bone. The transplant bone within chondroid bone was characterized by bone formation and remodeling 30 days after transplantation. Throughout the experiment, our findings demonstrated, for the first time, that the transplant bone that contains chondroid bone may be used clinically in relation to craniofacial bone defects to improve the treatment of bone grafts.     

Is the meniscus of the knee joint a fibrocartilage?

A histological analysis of the structure of intact knee joint menisci was carried out in adult dogs. By means of specific histochemical methods for the connective tissue and cartilage, it was found that the meniscus as a whole does not have a unique structure. The anterior and posterior horns are populated by round chondroid cells encircled by abundant interstitial substance and branched wavy connective fibers; blood vessels are present. The outer third of the meniscus is constituted of cross bundles of connective fibers, fibrocytes and spindle-like areas of loose connective tissue with blood vessels. The inner avascular two thirds of the meniscus are filled with parallel circumferentially oriented fascicles of connective fibers, ovally elongated chondroid cells, and a small quantity of chondroid interstitial substance. In some menisci, in the inner two thirds of the body, there are isles of typical cartilage, which show metachromasia of the beta type and rarely of the gamma type. The occurrence and way of the manifestation of cartilage are of an individual character. The structural duality of the knee meniscus is accounted for by its functional duality manifested in offering resistance to the forces of traction and pressure, the latter ones favoring the process of evolution of tissue from connective, through chondroid, to cartilaginous.     

Diagnosis of pulmonary hamartoma by fine needle biopsy

OBJECTIVE: To review the features of pulmonary hamartoma (PH) on fine needle biopsy (FNB), with emphasis on features that allow specific diagnosis. STUDY DESIGN: Fourteen cases of PH diagnosed on FNB were reviewed. The presence and volume of aspirate components were recorded. Attention was paid to features that might lead to false positive diagnosis of malignancy. Immunohistochemical staining for S100 was performed on cell block material. RESULTS: Fibromyxoid stroma and chondroid material were seen in 93% and 79% of cases, respectively; 71% demonstrated both components. Fibromyxoid stroma was prominent in the majority of cases; chondroid material was less abundant, being scanty in over half of cases. There were no cases in which epithelial cells represented the sole prominent component, and significant epithelial atypia was not identified. S100 staining was demonstrable in all cases in which stromal material was present in the cell block. CONCLUSION: A correct specific diagnosis of pH requires identification and correct interpretation of either fibromyxoid stroma or cartilaginous material. These components may show variable appearance on smears, with a range of potential mimics and pitfalls, but specific features are recognizable. Immunohistochemical staining of stromal material with S100 may lend support to the diagnosis.     

Chondroid bone on the upper pharyngeal jaws and neurocranial base in the adult fish Astatotilapia elegans

Serial cross sections of several adult specimens of the cichlid Astatotilapia elegans were used to investigate the fate and structure of the chondroid bone on the articulation between upper pharyngeal jaws and neurocranial base. The tissue persists in the adult on the three elements on which it previously developed, i.e., infrapharyngobranchial III-IV, parasphenoid, and basioccipital bones. It consists of haphazardly arranged, large vesicular cells without a canalicular system, embedded in a matrix histologically indistinguishable from bone matrix. Except for a narrow zone at the distal side, it is mineralized throughout. As in younger stages, the fibrous covering of the chondroid bone forms the articular tissue proper on each of the three elements. Acellular bone, found at the basal margin of the chondroid bone, it is argued, does not result from endochondral replacement of the latter but rather from dermal ossification projecting from the marrow cavity. Although lacunae may be filled in this way with bone, true obliteration of cells does not occur, so that there is no metaplasia from chondroid bone to bone. The part played by the chondroid bone in the outgrowth of the joint apophyses is discussed.     

Chondroid tissue in the development of stromal components of the heart

The chondroid tissue of the heart is an obligate provisional+ formation of the organ in question. It is formed during early stages of ontogenesis, develops maximally during the antenatal period and is preserved in the postnatal one. In a number of vertebrates it is the base for formation of cartilage and even bone in stroma of the heart. The ++chondroid tissue in embryos and fetuses performs, as regards the myocardium, stromal and trophic functions, further they are performed by the definitive connective-tissue stroma, in it vessels of the coronary system are situated. There are some reasons to suppose that the elements of the chondroid stroma are preserved during the postnatal ontogenesis in the myocardial intestinum, taking part in its metabolism.     

Fine needle aspiration cytology of primary extraskeletal myxoid chondrosarcoma. A case report

BACKGROUND: Extraskeletal myxoid chondrosarcoma is a rare soft tissue tumor of the extremities. Since it usually lacks obvious chondroid differentiation on light microscopy, it needs to be distinguished from other myxoid soft tissue sarcomas. CASE REPORT: The diagnosis of extraskeletal myxoid chondrosarcoma was made on fine needle aspiration in a patient with a swelling in the right calf. Cellular myxoid fragments having round to oval cells with grooved nuclei arranged in a cordlike pattern suggested chondroid differentiation. The diagnosis was confirmed by histopathology. CONCLUSION: Fine needle aspiration cytology can be diagnostic of extraskeletal myxoid chondrosarcoma even in the absence of obvious chondroid differentiation.     

Skeletal growth and chondroid tissue

Membranous and endochondral ossification processes are insufficient to describe all the aspects observed in the growing skeleton. The presence of chondroid tissue that we have identified by means of all modern histological techniques, including those able to detect the different types of collagen, has also to be explained. Present in the mandibular symphysis of either the human or cat fetuses, chondroid tissue has also been observed in the other parts of the mandible, in the sutural areas of the skull and in all the bones of both axial and appendicular skeleton. The differentiation of the mesenchyme into chondroid tissue could probably be related with mechanical forces exerted simultaneously in opposite directions or with a transient ischemia.     

Early development of the primitive cranial vault in the chick embryo.

The calcified tissues involved in the early morphogenesis of the cranial vault were studied by microradiographic analysis and histological techniques in 12 chick embryos on the 9th, 12th, and 14th days of incubation. On the 9th day, the frontal, parietal, and squamosal bones are comprised of a thin lamina of chondroid tissue deposited at a short distance from the fibers of the dura mater. Woven bone formation takes place in the calvarial mesenchyme only after the 12th day of incubation and occurs mainly on the external side of the chondroid primordium. The present data obviously indicate that the primitive desmocranium of the chick embryo, which is usually known to be formed by intramembranous ossification, consists first of chondroid tissue. This tissue represents thus the initial modality of skeletogenic differentiation within the cephalic mesenchyme of the cranial vault.     

Late skeletal development at the articulation between upper pharyngeal jaws and neurocranial base in the fish, Astatotilapia elegans, with the participation of a chondroid form of bone

This paper presents light-microscopical details of the late development of skeletal tissues at the joint between upper pharyngeal jaws (UPJs) and neurocranial base (parasphenoid and basioccipital bones) in the acellular-boned teleost Astatotilapia elegans. On each of the supporting elements, a bone tissue (AB) is deposited that is anomalous because of its retention of cells within the matrix. Later, this layer is gradually replaced by the anomalous large-celled chondroid kind of bone (CB). Both AB and CB probably grow by apposition from the overlying fibrous layer. Osteoblastlike cells secrete osteoid, which soon calcifies and traps the cells. As in young cellular membrane bone, cells in the AB have a wide, elongate shape and lie amidst sparse, calcified, bonelike matrix but lack a canalicular system. Later generations of enclosed cells have a more vesicular shape, with at least some cells remaining alive in the calcified matrix. Appositional growth of the chondroid bone at its articular side is matched from a certain stage onward by erosion at its basal side. On the upper pharyngeal jaws this resorption is clearly related to the development of new teeth. Although in older stages and adults the chondroid tissue resembles a secondary cartilage, the term chondroid bone (CB) was preferred because of (1) the continuing formation by osteoblastlike cells; (2) the staining affinities of its matrix with that of bone; and (3) its formation both on cartilage bone (the infrapharyngobranchials III-IV and basioccipital bone) and on membrane bone (the parasphenoid bone).     

Histology and histochemistry of the gekkotan notochord and their bearing on the development of notochordal cartilage

The persistence of the notochord into the skeletally mature life stage is characteristic of gekkotans, but is otherwise of rare occurrence among amniotes. The taxonomic diversity of Gekkota affords the opportunity to investigate the structure and development of this phylogenetically ancestral component of the skeleton, and to determine its basic characteristics. The gekkotan notochord spans almost the entire postcranial long axis and is characterized by a moniliform morphology with regularly alternating zones of chordoid and chondroid tissue. Chordoid tissue persists in the region of intervertebral articulations and occupies the cavitations that lie between the centra of the amphicoelous vertebrae. Chondroid tissue is restricted to zones in which the diameter of the notochord is reduced, corresponding to mid‐vertebral locations. In the tail, these zones of chondroid tissue are associated with the autotomic fracture planes. Chondroid tissue first manifests during late embryogenesis, appears to differentiate from pre‐existing chordoid tissue, and has the histological and histochemical characteristics of cartilage. Our observations lend support to the hypothesis that cartilage can be derived directly from notochordal tissue, and suggest that the latter may be an evolutionary and developmental precursor to chordate cartilage. The persistence of chordoid tissue in the intervertebral regions of amphicoelous vertebrae is consistent with a suite of paedomorphic traits exhibited by gekkotans and suggests that the typical hydrostatic nature of notochordal tissue may play a role in mechanically governing patterns of displacement between adjacent amphicoelous vertebrae that lack extensive centrum‐to‐centrum contact. Morphol., 2012. © 2012 Wiley Periodicals, Inc.     

An Immunohistochemical Study of Matrix Proteins in the Craniofacial Cartilage in Midterm Human Fetuses

Immunohistochemical localization of collagen types I, II, and X, aggrecan, versican, dentin matrix protein (DMP)-1, martix extracellular phosphoprotein (MEPE) were performed for Meckel’s cartilage, cranial base cartilage, and mandibular condylar cartilage in human midterm fetuses; staining patterns within the condylar cartilage were compared to those within other cartilaginous structures. Mandibular condylar cartilage contained aggrecan; it also had more type I collagen and a thicker hypertrophic cell layer than the other two types of cartilage; these three characteristics are similar to those of the secondary cartilage of rodents. MEPE immunoreactivity was first evident in the cartilage matrix of all types of cartilage in the human fetuses and in Meckel’s cartilage of mice and rats. MEPE immunoreactivity was enhanced in the deep layer of the hypertrophic cell layer and in the cartilaginous core of the bone trabeculae in the primary spongiosa. These results indicated that MEPE is a component of cartilage matrix and may be involved in cartilage mineralization. DMP-1 immunoreactivity first became evident in human bone lacunae walls and canaliculi; this pattern of expression was comparable to the pattern seen in rodents. In addition, chondroid bone was evident in the mandibular (glenoid) fossa of the temporal bone, and it had aggrecan, collagen types I and X, MEPE, and DMP-1 immunoreactivity; these findings indicated that chondroid bone in this region has phenotypic expression indicative of both hypertrophic chondrocytes and osteocytes.Key words: condylar cartilage, human fetus, extracellular matrix, MEPE, DMP-1     

Chondroid bone arises from mesenchymal stem cells in organ culture of mandibular condyles

Mandibular condyles of fetal mice 19 to 20 days in utero comprising clean cartilage and its perichondrium were cultured for up to 14 days, and their capacity to develop osteoid and to mineralize in vitro was examined. After 3 days in culture the cartilage of the mandibular condyle appeared to have lost its inherent structural characteristics, including its various cell layers: chondroprogenitor, chondroblastic, and hypertrophic cells. At that time interval no chondroblasts could be seen; instead, most of the cartilage consisted of hypertrophic chondrocytes. By that time, the surrounding perichondrium, which contains pluripotential mesenchymal stem cells, revealed the first signs of extracellular matrix enclosing type I collagen, bone alkaline phosphatase, osteonection, fibronectin, and bone sialoprotein as demonstrated by immunofluorescent techniques. Electron microscopic examinations of the newly formed matrix revealed foci of mineralization within and along collagen fibers as is normally observed during bone development. The composition of the latter mineral deposits resembled calcium pyrophosphate crystals. Following 14 days in culture larger portions of the condyle revealed signs of osseous matrix, yet the tissue reacted positively for type II collagen. Hence, the condylar cartilage, a genuine representative of secondary-type cartilage, elaborated in vitro a unique type of bone that would be most appropriately defined as chondroid bone. Biochemical assays indicated that the de novo formation of chondroid bone was correlated with changes in alkaline phosphatase activity and 45Ca incorporation. The findings of the present study imply that mesenchymal stem cells that ordinarily differentiate into cartilage possess the capacity to differentiate into osteogenic cells and form chondroid bone.     

Pleomorphic adenoma and adenoid-cystic carcinoma of salivary glands: immunohistochemical assessment of proliferative activity in comparison with flow-cytometric study

In this study, 32 pleomorphic adenomas (PAs) and seven adenoid cystic carcinomas (ACCs) were analysed for the evaluation of proliferating cell nuclear antigen (PCNA) indices and flow cytometric variables. Our aim was to assess any possible relationship between these parameters and the clinico-pathological variables and to clarify their histogenesis and reasons for their biological differences. The tumours were divided into three groups, mainly epithelial (E), myxoid (M) and chondroid (C); PCNA labelling index (LI) and weighted mean index (WI) and the WI/LI ratio were analysed in the predominant components; a single PCNA index, weighted by the percentage of each component, was also calculated. Only WI/LI was found to be significantly different in the three components, while PCNA single index did not show either significant differences by sex, age, site and size, or any correlation with the S phase fraction. A significant difference was found between PAs and ACCs by site (P <0.01) and DNA ploidy (P <0.05); furthermore, all PCNA indices (single index) were significantly lower in PAs than in ACCs.     

Chondrosarcoma of the trachea. A case report and literature review

The cytologic presentation of a case of chondrosarcoma of the trachea in a 72-year-old man is described. A mass detected on routine chest roentgenogram and defined by CT scan was used to make a touch imprint smear during partial tumor resection. The cytologic findings included round or polygonal cells with occasional binucleation, round hyperchromatic nuclei and prominent nucleoli, present in an amorphous pink-violet or light-blue background containing fragments of chondroid tissue. The histopathology was interpreted as a low-grade chondrosarcoma. Cartilaginous tumors of the trachea should be considered in the differential diagnosis of upper airway obstruction.