[Clinical, imaging and pathological and molecular characteristics of simple bone cyst]

Objective: To investigate the radiologic, pathologic, and molecular features of simple bone cysts (SBC), and their differential diagnoses. Methods: Fourteen cases of SBC were collected at the Department of Pathology, the First Affiliated Hospital of Nanjing Medical University from 2017 to 2022, and fluorescence in situ hybridization (FISH) was performed for retrospective analysis. Results: There were 14 patients, including 7 females and 7 males, with age range of 7 to 45 (median 29) years. The most common complaint was pain, including 4 cases with pathological fracture and 5 with history of previous trauma. The tumor size ranged from 3.4 to 13.5 (median 5.6) cm. The lesion involved the femur (n=4), humerus (n=5) and iliac bone (n=5). Radiologic diagnoses included SBC, aneurysmal bone cyst, and giant cell tumor of the bone or its combination with aneurysmal bone cyst-like region and fibrous dysplasia. Histologically, the cyst walls of the lesions were composed of fibrous tissue, fibrin-like collagen deposits, bone-like matrix and occasional woven bone. The lesional cells were spindled to ovoid, with scattered osteoclast-like giant cells, foamy histiocytes, hemosiderin deposits and cholesterol clefts. In 6 cases there were nodular fasciitis-like areas. Immunohistochemically, the spindled to ovoid cells were positive for SMA, EMA and SATB2 in varying degrees. FISH detection was performed in all 14 cases and EWSR1/FUS rearrangement were found in 9 cases. One case of FUS::NFATC2 fusion was detected by next-generation sequencing. Nine cases of SBC with the rearrangement were more cellular, and there were more mitotic figures in the recurrent FUS::NFATC2 fusion tumor. Clinical follow-up was obtained in all 14 cases with the time ranging from 5 to 105 (mean 46) months. Amongst them, the tumor with FUS::NFATC2 rearrangement had local recurrence twice after the first local excision, but had no more recurrence or metastasis 34 months after the subsequent segmental resection. The other 13 cases had no recurrence. Conclusions: EWSR1 or FUS rearrangement is most commonly identified in SBC, suggesting that SBC might be a neoplastic disease. In cases where the radiologic appearance and histomorphology are difficult to differentiate from aneurysmal bone cyst, FISH detection can aid in the definitive diagnosis.

Silencing of cytoskeleton-associated protein 2 represses cell proliferation and induces cell cycle arrest and cell apoptosis in osteosarcoma cells

Osteosarcoma is the most common primary bone malignancy, mainly occurring in children and adolescents. Cytoskeleton-associated protein 2 (CKAP2), which plays important roles in cell proliferation, has been reported to be overexpressed in diverse human cancers. In the present study, we aimed at exploring the expression and functions of CKAP2 in osteosarcoma. The mRNA and protein expression of CKAP2 was analyzed on collected osteosarcoma and control bone cyst tissues. The results indicated that CKAP2 expression was remarkably elevated in osteosarcoma tissues compared with bone cysts tissues. The expression level of CKAP2 in osteosarcoma was associated with overall survival, tumor size and tumor stage. In addition, down-regulation of CKAP2 by RNA interference in osteosarcoma cell lines, MG63 and SW1353, caused a remarkable inhibition in cell proliferation in vitro and xenograft growth in nude mice. Silencing of CKAP2 also significantly induced G0/G1 arrest and cell apoptosis of osteosarcoma cells. Furthermore, phosphorylation levels of Janus kinase 2 (JAK2) and Signal transducers and activators of transcription 3 (STAT3) were significantly reduced in CKAP2 knockdown cells. The expression of downstream targets of JAK2/STAT3 signaling, Cyclin D1, Bcl-2 and survivin, was also decreased in CKAP2 knockdown cells. Such aberrations can be rescued by re-expression of RNAi-resistant CKAP2. Collectively, the present study indicates that CKAP2 is a potential oncogene by targeting JAK2/STAT3 signaling, and that CKAP2 may serve as a novel target for osteosarcoma therapy.

Solid variant of aneurysmal bone cyst with a novel (X;9) translocation

Aneurysmal bone cysts (ABC) are locally destructive bone lesions occurring predominantly in young adults. There has been debate as to the neoplastic nature of these lesions. In recent years, however, compelling evidence of clonal chromosomal abnormalities has indicated a likely neoplastic origin. Although relatively few ABC have been assessed cytogenetically, many of those which have been studied have shown abnormalities of chromosome 17, particularly t(16;17)(q22;p13). We present a case of ABC in a 4-year-old female, which demonstrated the novel translocation t(X;9)(q26;q32).

A novel compound heterozygous mutation in the DAP12 gene in a patient with Nasu-Hakola disease

A 34-year-old woman showed clinical features characteristic of Nasu-Hakola disease (NHD), also designated polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL). The genetic analysis of the DAP12 gene (TYROBP) identified two heterozygous mutations composed of a previously reported single base deletion of 141G (141delG) in exon 3 and a novel single base substitution of G262T in exon 4, both of which are located on separate alleles. The protein sequence motif search indicated that both mutations encode truncated nonfunctional DAP12 polypeptides. This is the first case of NHD caused by compound heterozygosity for loss-of-function mutations in DAP12.

The genetic causes of basal ganglia calcification, dementia, and bone cysts: DAP12 and TREM2

BACKGROUND

Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL), or Nasu-Hakola disease, is a presenile dementia associated with loss of myelin, basal ganglia calcification, and bone cysts. It is caused by recessively inherited mutations in two genes encoding subunits of a cell membrane-associated receptor complex: TREM2 and DAP12. The clinical course of PLOSL has not been characterized in a series of patients with TREM2 mutations.

METHODS

The authors compare neurologic and neuroradiologic follow-up data of six patients carrying TREM2 mutations with PLOSL due to defective DAP12 genes. The authors review the known mutations in these two genes.

RESULTS

Mutations in DAP12 and TREM2 result in a uniform disease phenotype. In Finnish and Japanese patients with PLOSL, DAP12 mutations predominate, whereas TREM2 is mutated more frequently elsewhere.

CONCLUSIONS

Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy should be considered in adult patients under age 50 years with dementia and basal ganglia calcification. Radiographs of ankles and wrists, and DNA test in uncertain cases, confirm the diagnosis.

Neuropsychological tests and functional nuclear neuroimaging provide evidence of subclinical impairment in Nasu-Hakola disease heterozygotes

Nasu-Hakola disease is a rare, recessively inherited disease characterized by presenile dementia and bone cysts. Until now, no evidence of subclincal pathological changes in individuals heterozygous for the mutations underlying Nasu-Hakola disease has been reported. We performed a functional neuroimaging (99mTc-ECD SPECT) and neuropsychological study of healthy members of an Italian family carrying a mutation in the TREM2 gene. Two healthy subjects heterozygous for one mutated TREM2 allele showed a deficit of visuospatial memory associated with hypoperfusion in the basal ganglia, whereas the homozygotes for the wild-type allele of TREM2 did not show any abnormalities.

Nasu-Hakola disease: a rare entity in Italy. Critical review of the literature

Nasu-Hakola disease (NHD, polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy, PLOSL) is a recessively inherited disorder characterized by systemic bone cysts and progressive presenile dementia associated with sclerosing encephalopathy. The disease has a worldwide distribution, but most patients have been reported in Finland and in Japan; in Italy there are anecdotal reports. The combination of neuropsychiatric symptoms and bone cysts is unique to this disease, which we believe to be underestimated in Italy. The molecular defect has been identified in loss-of-function mutations in the TYROBP gene in Finnish and in Japanese patients, and in the TREM2 gene in other families of different ethnic origins. We reviewed the international literature to define better the diagnostic steps and to draw the attention of neurologists and orthopaedic specialists to the disease. The identification of new cases followed by appropriate genetic counselling, genetic analysis, and study of the territorial distribution of affected patients could be a good strategy to follow in order to improve understanding of the disease.

Heterogeneity of presenile dementia with bone cysts (Nasu-Hakola disease): three genetic forms

Nasu-Hakola disease (NHD) is an autosomal recessive disorder characterized by presenile dementia and bone cysts. Finnish patients revealed a large deletion in DAP12 gene encoding a key element for transducing activation signal. The authors examined six Japanese cases for DAP12 alleles. Five of the six had loss-of-function mutation, either a single-base deletion or a novel point mutation. The single patient without mutation normally expressed DAP12 protein. Japanese NHD has at least three genetic forms regarding DAP12.

Translocation (16;20)(p11.2;q13). sole cytogenetic abnormality in a unicameral bone cyst

We report the results of cytogenetic analysis of a case of unicameral bone cyst with a t(16;20(p11.2;q13) present as the sole abnormality. To our knowledge, this is only the second report of a cytogenetically characterized tumor of this type.

[Presenile dementia in polycystic lipomembranous osteodysplasia]

We present a 36-year-old woman with a 3-year history of cognitive decline followed by development of a small stepped gait and urinary and fecal incontinence. Workup revealed multiple bone cysts documented by X-ray and idiopathic hyperprolactinoma. An MRI confirmed the CT finding of massive bilateral basal ganglia calcification. This is the first case of polycystic lipomembranous osteodysplasia described in Germany. We conclude that patients with presenile dementia, psychosis, or early-onset Parkinsonism associated with basal ganglia calcification should undergo X-rays of hand and feet to rule out polycystic lipomembranous osteodysplasia.

CNS manifestations of Nasu-Hakola disease: a frontal dementia with bone cysts

BACKGROUND

Nasu-Hakola disease or polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL) is a genetically heterogeneous disease characterized by a combination of systemic bone cysts and dementia.

OBJECTIVE

The authors present a neurologic, neuroradiologic, and neuropathologic analysis of a series of PLOSL patients in which the diagnosis has been confirmed by molecular genetic methods.

METHODS

Clinical, neurophysiologic, and imaging follow-up data on eight patients as well as autopsy samples of three patients were analyzed in this study. All eight patients were homozygous for a loss-of-function mutation in the DAP12 gene.

RESULTS

In most patients, the disease debuted with pain in ankles and wrists after strain during the third decade, followed by fractures caused by cystic lesions in the bones of the extremities. Frontal lobe syndrome and dementia began to develop by age 30, leading to death by age 40. Neuroimaging disclosed abnormally high and progressively increasing bicaudate ratios and calcifications in the basal ganglia as well as increased signal intensities of the white matter on T2-weighted MR images even before the appearance of clinical neurologic symptoms. Three patients who had undergone autopsies showed an advanced sclerosing leukoencephalopathy with frontal accentuation, widespread activation of microglia, and microvascular changes.

CONCLUSIONS

Although PLOSL in most patients manifests by bone fractures, some patients do not show any osseous symptoms and signs before the onset of neurologic manifestations. Consequently, patients with frontal-type dementia of unknown origin should be investigated by x-ray of ankles and wrists. The current results suggest early basal ganglia involvement in PLOSL.

The ITAM-bearing transmembrane adaptor DAP12 in lymphoid and myeloid cell function

DAP12, an ITAM-bearing transmembrane adaptor protein, associates non-covalently with receptors in natural killer (NK) and myeloid cells, and provides signaling function via the Syk and ZAP-70 tyrosine kinase activation pathways. Humans and mice lacking DAP12 (DAP12(-/-)) show normal development of hematopoietic cells. However, DAP12(-/-) humans develop presenile dementia and bone cysts, and DAP12(-/-) mice show impaired immune responses.

Loss-of-function mutations in TYROBP (DAP12) result in a presenile dementia with bone cysts

Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL; MIM 221770), also known as Nasu-Hakola disease, is a recessively inherited disease characterized by a combination of psychotic symptoms rapidly progressing to presenile dementia and bone cysts restricted to wrists and ankles. PLOSL has a global distribution, although most of the patients have been diagnosed in Finland and Japan, with an estimated population prevalence of 2x10-6 (ref. 2) in the Finns. We have previously identified a shared 153-kb ancestor haplotype in all Finnish disease alleles between markers D19S1175 and D19S608 on chromosome 19q13.1 (refs 5,6). Here we characterize the molecular defect in PLOSL by identifying one large deletion in all Finnish PLOSL alleles and another mutation in a Japanese patient, both representing loss-of-function mutations, in the gene encoding TYRO protein tyrosine kinase binding protein (TYROBP; formerly DAP12). TYROBP is a transmembrane protein that has been recognized as a key activating signal transduction element in natural killer (NK) cells. On the plasma membrane of NK cells, TYROBP associates with activating receptors recognizing major histocompatibility complex (MHC) class I molecules. No abnormalities in NK cell function were detected in PLOSL patients homozygous for a null allele of TYROBP.

Polycystic bone disease: A new, autosomal dominant disorder

We describe a new heritable bone disease characterized radiographically by increasingly numerous and enlarging cyst-like lesions throughout the skeleton. Beginning in early childhood, a father, son, and daughter all suffered from progressively frequent pathological fractures involving such radiolucencies. Healing occurred uneventfully and with little residual pain or deformity. Biochemical parameters of mineral homeostasis and skeletal turnover were normal. Bone scanning showed increased radioisotope uptake primarily in fractures and in the largest collections of the lesions. The histopathology is uncertain, but may reflect a form of intraosseous lipomatosis. This unique condition, which we have provisionally named polycystic bone disease, is inherited as an autosomal dominant trait with a high degree of penetrance.

Assignment of the locus for PLO-SL, a frontal-lobe dementia with bone cysts, to 19q13

PLO-SL (polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy) is a recessively inherited disorder characterized by systemic bone cysts and progressive presenile frontal-lobe dementia, resulting in death at <50 years of age. Since the 1960s, approximately 160 cases have been reported, mainly in Japan and Finland. The pathogenesis of the disease is unknown. In this article, we report the assignment of the locus for PLO-SL, by random genome screening using a modification of the haplotype-sharing method, in patients from a genetically isolated population. By screening five patient samples from 2 Finnish families, followed by linkage analysis of 12 Finnish families, 3 Swedish families, and 1 Norwegian family, we were able to assign the PLO-SL locus to a 9-cM interval between markers D19S191 and D19S420 on chromosome 19q13. The critical region was further restricted, to approximately 1.8 Mb, by linkage-disequilibrium analysis of the Finnish families. According to the haplotype analysis, one Swedish and one Norwegian PLO-SL family are not linked to the chromosome 19 locus, suggesting that PLO-SL is a heterogeneous disease. In this chromosomal region, one potential candidate gene for PLO-SL, the gene encoding amyloid precursor-like protein 1, was analyzed, but no mutations were detected in the coding region.

Complex cytogenetic rearrangement in a case of unicameral bone cyst

Cytogenetic analysis of a unicameral bone cyst surgically resected in an 11-year-old boy revealed a highly complex clonal structural rearrangement involving chromosomes 4, 6, 8, 16, 21, and both 12. These findings reinforce the need for further studies on unicameral bone cysts to verify the frequency and to understand the significance of chromosome anomalies in this type of lesion.

[Cell proliferation in bone tumors. Immunohistologic study of Ki-67 protein expression]

Bone tumors represent a group of tumors of various dignity. In spite of this single tumor entities may display strong morphological resemblance to each other which can in turn result in profound difficulties in differential diagnosis. The biological behaviour of a tumor is mainly determined by its rate of proliferation. In this study the rate of proliferation of 64 bone tumors (30 high-grade central osteosarcomas, 6 low-grade osteosarcomas, 8 giant cell tumors, 8 aneurysmatic bone cysts, 5 osteoidosteomas/osteoblastomas, 7 fibrous dysplasias and 5 cases of a myositis ossificans) were analysed. Immunohistochemistry was performed on paraffin-embedded tissue sections using the MIB-1 monoclonal antibody. MIB-1 recognizes the proliferation-associated Ki-67 protein which is expressed during the active phases of the cell cycle but cannot be detected in senescent cells. Among high-grade central osteosarcomas a significantly higher rate of proliferation (average value 30%) was found in comparison with low-grade osteosarcomas and other benign intraosseous bone tumors. This approach proved to be very useful in the distinction between high-grade and low-grade osteosarcomas as well as bone-forming intraosseous tumors. However distinguishing low-grade osteosarcomas from benign bone tumors by determining only the rate of proliferation was not possible, although interestingly, the proliferative rate of myositis ossificans, a purely reactive lesion, was in the range of the values determined for high-grade osteosarcoma.

[DNA cytometry of solitary and aneurysmal bone cysts and low malignancy and high malignancy central osteosarcomas. Current significance within the scope of morphologic diagnosis of intraosseous cystic and osteoblastic lesions]

DNA cytometric investigations of intraosseous cystic lesions and osteoblastic tumors may be helpful in morphological diagnosis. The detection of a DNA-aneuploid stemline supports the diagnosis of a high-grade malignant bone neoplasm, even in small biopsies. Solitary and aneurysmal bone cysts have DNA-diploid cell populations. Low-grade central osteosarcomas may show single-cell aneuploidies of varying extent as well as a DNA-diploid stemline. Their presence may be a sign of genetic instability within the population of neoplastic cells before a DNA-aneuploid stemline is established and should prompt careful postoperative observation.

Neuropsychiatric and brain CT findings in polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy

Seven patients with polycystic lipomembranous osteodysplasia and sclerosing leukoencephalopathy (PLO-SL or membranous lipodystrophy) were examined clinically and with CT scanning. The degree of dementia was severe in five cases, marked in one case, and mild in one case. All patients suffered from marked or severe prefrontal psychosyndrome, impairment of memory and signs of upper motor neuron involvement. Epileptic seizures and primitive reflexes were observed in six cases. Degree of agnostic-aphasic-apraxic symptoms varied. In all cases CT revealed general and diffuse brain atrophy, which was accentuated in frontal areas. In the basal ganglia bilateral calcifications (five cases) or a slight hyperdensity (two cases) were detected. CT finding in PLO-SL may lead to an early diagnosis of this fatal disease.

Cytogenetic findings in aneurysmal bone cysts

Cytogenetic analysis was performed on samples from ten patients diagnosed with aneurysmal bone cyst. Six of the patients were male and four were female, with ages ranging from 7 to 24 years. Results were obtained in eight of the cases; all were karyotypically normal.

[Genetic and environmental factors in the families of children with dystrophic bone cysts]

On the basis of data of 49 probands' families with dystrophic osseous, cyst, 12 probands' families with giant cell tumor and 55 children from the general population by means of clinical and multidimensional-genetical analysis (cluster, discriminant) have been revealed genetical and environmental factors, contributing to the formation of the osseous cysts in children. There have been developed the directions of the search of the "principal" environmental and genetical factors, determined the qualitative criteria of the factor significance, revealed the structures of the mutual connection of the significant factors and obtained their prognostication value definition.

Membranous lipodystrophy (lipomembranous polycystic osteodysplasia). Two case reports

Membranous lipodystrophy, a hereditary disease, is characterized by symmetric multiple cystic bone lesions and progressive neuropsychiatric symptoms. In two patients, a 22-year-old woman and a 30-year-old man, as in others reported in the literature, neither the etiology nor the pathogenesis was apparent. Histologically, the lesions consisted of convoluted membranes interlaced with lipoid structures.

Neurophysiological findings in the hereditary presenile dementia characterised by polycystic lipomembranous osteodysplasia and sclerosing leukoencephalopathy

17 patients suffering from the presenile dementia characterised by polycystic lipomenbranous osteodysplasia and sclerosing leukoencephalopathy were studied neurophysiologically. Noteworthy findings were diffuse slowing, the accentuation of 6-8 Hz parasagittal activity, slowing of the dominant occipital rhythm and, in the late phase when 13 of patients got epileptic seizures, there was paroxysmal activity in the EEG.

Cerebral gigantism associated with jaw cyst basal cell naevoid syndrome in two families

We report 9 subjects from 2 families with the syndrome of cerebral gigantism, seven of the patients also had jaw cyst basal cell naevoid syndrome. Neurological, radiological, somatic and biochemical features of this hitherto unreported association are described. Neurological symptoms included mild hydrocephalus, ventricular malformation, cerebellar syndrome, intracranial calcification, oculomotor disturbances, EEG abnormalities and rarely, mild peripheral nervous disorders. A disturbance of calcium metabolism appears to be a prominent feature of the genetically determined nonprogressive syndrome.

Nevoid basal cell carcinoma syndrome: radiographic manifestations including cystlike lesions of the phalanges

The radiographic findings in 25 patients with the nevoid basal cell carcinoma syndrome are presented. Cystlike lucencies of the phalanges, a previously unreported finding, were seen in 46% of the patients in whom hand films were obtained. Mandibular cysts, present in 42% of cases, and exuberant intracranial calcifications were also characteristic features. Brachymetacarpalia, and rib and spine anomalies were also associated with the syndrome but are less specific findings.

Basal cell nevus syndrome

We report two patients with basal cell nevus syndrome. They had two previously unreported associated conditions--a myocardial fibroma and bilateral basal cell carcinomas of the soles of the feet. The syndrome is discussed, the literature is reviewed, and the management is outlined.

What is Gorlin's syndrome? The diagnosis and management of the basal cell naevus syndrome, based on a study of thirty-seven patients

A series of 37 patients with Gorlin's syndrome is described; 23 had the typical naevi, 19 had jaw cysts and only 10 had both. A wide range of associated deformities was noted. The need for early identification of patients at risk is stressed; follow-up is essential for 2 reasons: The naevi although indistinguishable histologically from basal cell carcinomas only rarely require radical removal. The jaw cysts are locally invasive and should be radically removed when small. In 8 patients examined there was a low level of alpha-globulins in the plasma. Spontaneous involution of the naevi may occur in un-irradiated skin.

Bone mineral content in hereditary polycystic osteodysplasia associated with progressive dementia

Measurements of the bone mineral content were made in five patients with a disease characterized by progressive dementia and lipomembranous polycystic osteodysplasia. Decreased bone mineral density (g/cm3) was observed not only in the region of cysts in the distal radius but also in the diaphyses of radius and ulna. The 85Sr vertebral uptake was low in the youngest patient, normal in two and raised in another two. The observations were compatible with the hypothesis of a general metabolic disorder of the bone.

[Multiple cysts of the jaws: basocellular nevomatosis]

The authors presents two cases of basocellular nevomatosis with multiple maxillary cysts. He thought it important to point out the presence of a cyst in the left styloid apophysis, as up to now, epidermoid cysts have never been observed in other facial bones apart from the maxillae in BCN. In conclusion, the author presents three casses, which although showing multiple cysts or pseudocysts of the maxillae, do not belong to the BCN syndrome.

[Clinical characteristics and genetic identity of the basal cell nevus syndrome (Gorlin-Goltz syndrome)]

The clinical, genetic, radiological, dental and dermatological aspects of 3 patients with the autosomal dominant basal cell naevus syndrome are reported. An analysis of the phenotypic features of 72 cases described in the literature is presented and compared with a previous analysis. Ash leaf hypopigmentation similar to that found in tuberous sclerosis represents a unique finding in this syndrome. Other similarities to the phacomatoses are discussed. We were able to support a previous report that patients with the basal cell naevus syndrome have a normal end-organ response to parathormone stimulation, and that it is most probably not related to pseudohypoparathyroidism, as earlier reports suggested.

Older paternal age and fresh gene mutation: data on additional disorders

Older paternal age has previously been documented as a factor in sporadic fresh mutational cases of several autosomal dominant disorders. In this collaborative study, an older mean paternal age has been documented in sporadic cases of at least five additional dominantly inheritable disorders; the basal cell nevus syndrome, the Waardenburg syndrome, the Crouzon syndrome, the oculo-dental-digital sysdrome, and the Treacher-Collins syndrome. It was also found to be a factor in acrodysostosis and progeria, suggesting a fresh mutant gene etiology for these two conditions in which virtually all cases have been sporadic and the mode of genetic etiology has been unknown.