Perineal lipoblastoma: a case report and review of literature

Lipoblastoma is a rare benign mesenchymal tumor that composes of embryonal white fat tissue and typically occurs in infants or young children under 3 years of age. It usually affects the extremities, trunk, head, and neck. The perineum is a rare location with only 7 cases reported in the literature. We describe a case of 3-year-old girl with a lipoblastoma arising from perineum. An approximately 4.5 cm × 3.5 cm × 2.5 cm nodule was resected in left perineum with satisfied results. Pathological examination showed that it was composed of small lobules of mature and immature fat cells, separated by fibrous septa containing small dilated blood vessels. The left perineal lipoblastoma, although rare, should be differentiated from some other mesenchymal tumors with similar histologic and cytological features.     

Fine-needle aspiration cytology of lipoblastoma: a report of two cases

Lipoblastoma is an uncommon lipomatous tumor that typically occurs in infants and children. It may present as a single subcutaneous nodule or with multiple lesions (lipoblastomatosis). We describe fine-needle aspiration (FNA) cytologic features of two cases that presented as a subcutaneous lump in the scapular area and as a deeply located mass in the left arm. Smears showed fragments of adipose tissue that consisted of numerous vacuolated adipocytes with few stroma. Nuclei were small and located centrically, without indentations. Myxoid stromal material was a remarkable finding in one case. Both cases showed small delicate vessels, mainly in relation with the myxoid material. No necrosis, atypia, or mitotic figures were present. Cytologic features were characteristic enough to permit a specific diagnosis (adipose tumor suggestive of lipoblastoma). The differential diagnosis should consider lipoma with regressive changes, well-differentiated and mixoid liposarcoma. In addition to cytologic features, the patient's age is very useful for differentiation.     

Desmin‐positivity in spindle cells: Under‐recognized immunophenotype of lipoblastoma

Lipoblastoma is a distinct benign fatty tumor composed of adipocytes, lipoblasts, and primitive mesenchymal cells with a myxoid stroma. Lipoblastoma harbors characteristic fusion genes involving the PLAG1, resulting in aberrant expression of PLAG1. However, the nature of the primitive mesenchymal cells remains obscure. In our routine pathology practice, we noticed desmin‐positive spindle mesenchymal cells in lipoblastomas, which is a hitherto poorly described phenomenon. Thus, we examined the expression of several myogenic markers including desmin in a variety of 95 mesenchymal tumors with fatty elements. Fourteen of the 15 lipoblastomas examined contained desmin‐positive spindle cells, which also showed nuclear expression of PLAG1, whereas α‐smooth muscle actin, muscle specific actin, h‐caldesmon, and myogenin were negative. Some spindle cells in subsets of atypical lipomatous tumors/well differentiated liposarcomas (6/20), dedifferentiated liposarcomas (11/31) and pleomorphic liposarcomas (2/10) were positive for actins and/or desmin, supporting focal myofibroblastic or smooth muscle differentiation. The other tumors, including 11 myxoid/round cell liposarcomas, four spindle cell lipomas, and four lipofibromatoses, were negative for all of the myogenic markers assessed. The almost consistent desmin expression in spindle mesenchymal cells suggests a potential diagnostic utility of this marker and myofibroblastic phenotype of fractions in lipoblastoma cells.     

Lipoblastoma in adolescents and young adults: report of six cases with FISH analysis

Aims:  Lipoblastoma is a rare benign adipocytic neoplasm that occurs primarily in infancy and early childhood. Histologically, there is some morphological overlap with atypical lipomatous tumour and myxoid liposarcoma and the age at presentation is often regarded as a major diagnostic criterion. However, we recently encountered several cases of lipoblastoma occurring in adolescents and young adults. The aim was to document the occurrence of lipoblastoma in older patients, with cytogenetic confirmation.
Methods and results:  Six cases of lipoblastoma in patients >12 years old were identified. The tumours occurred in four male and two female patients ranging from 14 to 24 years old. Our cases showed the classical histological features of lipoblastoma. Three tumours were composed predominantly of mature adipocytes and the three other cases showed an immature appearance, with a prominent myxoid matrix. Fluorescence in situ hybridization (FISH) demonstrated rearrangements of the PLAG1 region in two cases and polysomy for chromosome 8 in three other cases. None of the tumours had amplification of MDM2 or CDK4.
Conclusions:  Lipoblastoma occurs rarely in young adults and should enter into the differential diagnosis of 'atypical' fatty tumours in adults. Our report underscores the diagnostic value of FISH analysis.     

Rearrangement of chromosomal region 8q11-13 in lipomatous tumours: correlation with lipoblastoma morphology

Cytogenetics is of considerable value when diagnosing lipomatous tumours, as different tumour types have different more or less specific chromosomal abnormalities. One such entity is lipoblastoma, which is a benign lipomatous tumour that often exhibits rearrangements of chromosome bands 8q11-13, and the gene PLAG1 has been implicated as the target of these chromosomal changes. All lipomatous tumours karyotyped at the Norwegian Radium Hospital were reviewed, looking for rearrangements of 8q11-13. Five tumours exhibiting chromosomal abnormalities affecting this region were found. Only one of them was morphologically diagnosed as a lipoblastoma, two being classified as lipomas, one as a hibernoma, and one as a well-differentiated liposarcoma. The two tumours successfully analysed with bacterial artificial chromosomes (BACs) covering the gene PLAG1 showed involvement of this gene in the rearrangement. The findings raise the question as to what extent the diagnosis lipoblastoma should be based on histopathological or cytogenetic/molecular data or a combination thereof. When karyotypic information from this series was combined with available literature data, it was found that the sensitivity of 8q11-13 rearrangements for diagnosing lipoblastomas when found in a lipomatous tumour was 77% and that the corresponding specificity was 98%. The validity of these calculations of the diagnostic information provided by the cytogenetic findings is, of course, totally dependent on the morphological diagnosis made in each case. Regardless of what the precise phenotypic diagnosis was, it is suggested that lipomatous tumours with 8q11-13 rearrangement constitute a distinct pathogenetic entity. When selective therapies tailor-made against the specific pathogenetic rearrangement become available, it will become mandatory to pay more attention to the genetic constitution of the tumour cells than to their phenotypic appearance.     

Cytological features of lipoblastoma: a report of three cases

Lipoblastoma is a rare benign neoplasm occurring mostly in children under the age of three. Accurate preoperative diagnosis is mandatory for planning the treatment. The main aim of this study is to establish the cytological features of lipoblastoma and to answer the question: “Is cytological diagnosis of lipoblastoma reliable?” Preoperative fine‐needle aspiration biopsy (FNAB) and tissue sections of three children treated for lipoblastoma at the Division of Pediatrics, University Medical Center, Ljubljana, Slovenia, in the period from 1997 to 2004 were reexamined. The Giemsa‐ and Papanicolaou‐stained FNAB smears were moderately or poorly cellular and contained lipocytes, lipoblasts, and spindle cells in various proportions. The tumor cells were in clusters and tissue fragments or as single cells. Thin branching capillaries were observed in most of the clusters and tissue fragments. In the background, abundant myxoid extracellular material and naked oval nuclei were present. In the first case, the cytological diagnosis was benign soft‐tissue tumor, in the second the diagnosis was not conclusive and the last case was correctly diagnosed as lipoblastoma. In the differential diagnosis of the second case, both lipoblastoma and liposarcoma were considered cytologically as well as histologically. At 7‐yr follow‐up, there is no evidence of the disease. Thus, we conclude that lipoblastoma with typical cytological features could be accurately diagnosed by FNAB. However, tumors containing numerous lipoblasts could pose a diagnostic problem. Diagn. Cytopathol. 2005;33:195–200. © 2005 Wiley‐Liss, Inc.     

Fine-needle aspiration cytology of a lipoblastoma: a case report

A lipoblastoma is a rare benign tumor of immature white fat, and more than 90% of lipoblastomas occur before the age of 3 years. The diagnosis of a lipoblastoma is mostly dependent on a histopathological examination of a surgically excised specimen. However, an accurate preoperative diagnosis is essential for the planning of surgery, particularly for a lesion of the head and neck area. We experienced a case of a cervical lipoblastoma of a 23-month-old boy. A preoperative fine-needle aspiration biopsy showed the sample as moderately cellular and showed fragments of mature and immature adipose tissues containing a large number of capillary vessels. There were numerous lipoblast-looking cells with a multivacuolated cytoplasm, and the nuclei were small, compressed by vacuoles, and centrally located. According to the cytological findings, the lesion was diagnosed as a benign adipose tumor suggestive of a lipoblastoma. Subsequent surgical excision confirmed the diagnosis of the fine-needle aspiration biopsy. The cytologic features of lipoblastoma are not well known because of the rarity of the lesion. However, the fine-needle aspiration cytological features of a lipoblastoma are sufficiently characteristic to make a specific preoperative diagnosis.     

Pericardial synovial sarcoma, a potential for misdiagnosis: clinicopathologic and molecular cytogenetic analysis of three cases with literature review

Synovial sarcomas arising in unexpected locations may lead to diagnostic challenges. In this report, we describe 3 cases of synovial sarcoma that manifested clinically as primary pericardial lesions. All 3 cases occurred in men in their fourth decade. Fever, cough, chest pain, and chest distress were the most common symptoms. Histologically, 2 of the tumors were spindle cell monophasic, and 1 tumor was biphasic. By immunohistochemical studies, the tumor cells were positive for cytokeratins and epithelial membrane antigen. In addition, the tumor cells displayed focal immunoreactivity for calretinin, cytokeratin 5/6, and HBME-1, resulting in the initial interpretations of malignant mesotheliomas. None of the 3 cases were diagnosed correctly until subsequent molecular cytogenetic assays demonstrated the presence of SYT gene rearrangements. As there are overlapping morphologic features between pericardial synovial sarcoma and mesothelioma, molecular analysis is essential for differential diagnoses.     

脂肪母细胞瘤44例临床病理分析

目的　探讨脂肪母细胞瘤的临床、病理及预后。方法　对 4 4例脂肪母细胞瘤临床资料、病理切片和随访结果进行分析。结果　脂肪母细胞瘤 ,手术切除时的平均年龄为 (2 0 8± 14 6 )个月 ,患儿最大 5岁 ,男性多于女性。病变多发生于四肢、头颈部、腰背部及腋部。复发率 18 2 % ,弥漫型明显多于局限型。肿瘤最大径多为 3～ 7cm ,切面比脂肪瘤灰白。镜下见未成熟和成熟的脂肪组织小叶由丰富毛细血管、小静脉的狭窄纤维间隔分割 ,伴不同程度的黏液样基质。结论　脂肪母细胞瘤需与黏液脂肪肉瘤、纤维脂肪肉瘤和婴儿纤维性错构瘤相鉴别。脂肪母细胞瘤生物学行为完全良性 ,虽有局部复发 ,但从无转移及恶变 ,治疗方法主要为局部切除     

Case of lipoblastoma with two derivative chromosomes 8 containing homogeneously staining-like regions and a review of the literature: lipoblastoma and chromosome 8

We report a case of a lipoblastoma in a 10-month-old girl in which the cytogenetic aberration showed a homogeneously staining-like region (hsr) within two derivative chromosomes 8. There was a loss of one normal copy of chromosome 8 and gain of two identical derivative chromosomes 8 with the karyotype designation 47,XX,psu idic(8)(pter-->q12 approximately 13::hsr::q12 approximately 13-->pter),+psu idic (8)(pter-->q12 approximately 13::hsr::q12 approximately 13-->pter). This is the first report of a chromosomal aberration of this type seen in lipoblastoma.     

Cardiac myxoma: a cytogenetic study of two cases

Two cases of cardiac myxoma, each arising in the left atrium, are presented. One tumor contained the clonal abnormality i(17)(q10),der(20)t(1;20)(q21;q11.2) and the second tumor contained add (9)(p22),+12. Such rearrangements have not been previously reported in these tumors.     

Tracheobronchopathia osteochondroplastica: two cases and a review of the literature

Introduction: Tracheobronchopathia osteochondroplastica (TO) is a rare disorder involving the lumen of the trachea-bronchial tree and characterized by multiple sub-mucosal osseous and cartilaginous nodules in the trachea and bronchus, sparing the posterior wall. We here report two cases of patients with tracheobronchopathia osteochondroplastica and review the relevant literature briefly. Case presentation. Case 1 was a 64-year-old woman with a history of Chronic Obstructive Pulmonary Disease (COPD) who presented with frequent non-productive cough for 2 years. Chest computed tomography (CT) showed signs consistent with COPD and evident irregular narrowing of the tracheal and both main bronchial lumen caused by calcific foci. Fibre optic bronchoscope (FOB) was performed and showed dozens of sub-mucosal nodules protruding into the lumen of lower half of the trachea and both main bronchi. Histopathological exam demonstrated sub-mucosal ossification and cartilage in the sample. Her follow-up has been uneventful for 3 years. Case 2 was a 37-year-old man presented with hoarseness, exertional dyspnea, and intermittent dry cough for about 3 years. Chest CT scans showed irregular nodules around the entire circumference of the trachea extending from sub-glottic region to lower trachea. FOB showed glottic stenosis and diffused sub-mucosal calcified nodules protruding from the antero-lateral portion of the trachea in the subglottic region. Over the following 12 months, his disease is stable. Conclusions. TO is a rare, benign disease with slow progression, clinicians should be aware of TO and should consider it in patients with chronic cough, recurrent respiratory infection and evolving exertional dyspnea.     

Tracheobronchopathia osteochondroplastica: two cases and a review of the literature

Introduction: Tracheobronchopathia osteochondroplastica (TO) is a rare disorder involving the lumen of the trachea-bronchial tree and characterized by multiple sub-mucosal osseous and cartilaginous nodules in the trachea and bronchus, sparing the posterior wall. We here report two cases of patients with tracheobronchopathia osteochondroplastica and review the relevant literature briefly. Case presentation: Case 1 was a 64-year-old woman with a history of Chronic Obstructive Pulmonary Disease (COPD) who presented with frequent non-productive cough for 2 years. Chest computed tomography (CT) showed signs consistent with COPD and evident irregular narrowing of the tracheal and both main bronchial lumen caused by calcific foci. Fibre optic bronchoscope (FOB) was performed and showed dozens of sub-mucosal nodules protruding into the lumen of lower half of the trachea and both main bronchi. Histopathological exam demonstrated sub-mucosal ossification and cartilage in the sample. Her follow-up has been uneventful for 3 years. Case 2 was a 37-year-old man presented with hoarseness, exertional dyspnea, and intermittent dry cough for about 3 years. Chest CT scans showed irregular nodules around the entire circumference of the trachea extending from sub-glottic region to lower trachea. FOB showed glottic stenosis and diffused sub-mucosal calcified nodules protruding from the antero-lateral portion of the trachea in the subglottic region. Over the following 12 months, his disease is stable. Conclusions: TO is a rare, benign disease with slow progression, clinicians should be aware of TO and should consider it in patients with chronic cough, recurrent respiratory infection and evolving exertional dyspnea.     

Non-ossifying fibroma or benign lipoblastoma of bone–an electron-microscopic and histochemical study

An ultrastructural and histochemical analysis was made of a lesion identified by light microscopy as a non-ossifying fibroma of bone. A histogenetic sequence was traced from spindle-shaped fibroblast-like cells to multivacuolated lipoblasts with abundant glycogen. These lipid-laden cells showed remarkable similarity to some cells of a well differentiated liposarcoma. Others have interpreted the lipid-containing cells of non-ossifying fibroma as representing fibroblasts which have imbibed or synthesized lipid or lipid-laden macrophages. Our studies demonstrate that this tumour consists of primitive mesenchymal cells with partial maturation to early lipoblasts, suggesting its classification as a benign lipoblastoma of bone.     

Desmoplastic malignant mesothelioma: two cases and a literature review

We present two cases of desmoplastic malignant mesothelioma (DMM) with pathological, immunohistochemical, and ultrastructural features. Each patient showed rapid progress and died within 1 year from appearance of the initial symptoms. Macroscopically, both showed a thickened pleura replaced by a tumor that encased the lung. Microscopic results of each showed that the tumors consisted of a dense fibrous area, with mild nuclear irregularities and hyperchromatism. In case 1, the tumor had invaded the diaphragm, chest wall, and cardiac sac; the mass in case 2 invaded the lung and diaphragm, and distal metastases were seen in the thoracic vertebrae, meninges, and liver. Ultrastructural findings in case 1 showed a few short blunt microvilli on the cell surfaces. DMM is occasionally difficult to distinguish from fibrous pleurisy and solitary fibrous tumor. Immunohistochemical examinations of the present cases showed the expression of cytokeratin and vimentin, and focal positive stainings of antihuman mesothelial cell antibody (HBME-1) in both, whereas CD34 and bcl2 were negative. Solitary fibrous tumor was excluded. Therefore, pathological, ultrastructural, and immunohistochemical findings led us a diagnosis of DMM in each case. The Ki-67 labeling index (Ki-67 LI) of cases 1 and 2 was 25.5 and 15.5, respectively, both high, which suggested malignancy. Widespread immunohistological panels of malignant mesothelioma were not evaluated; Immunohistological markers commonly used for the diagnosis of malignant mesothelioma were not evaluated; however, the high ki-67 LI results and positive HBME-1 staining were helpful factors for the diagnoses of DMM.     

Intrascrotal lipoblastoma with a complex karyotype: a case report and review of the literature

Lipoblastoma is a tumor of adipose tissue that usually occurs in young children. Most lipoblastomas occur on the extremities, trunk, and head and neck, and most have rearrangements of the 8q region. We describe a lipoblastoma in a 12-month-old boy who presented with a rapidly enlarging scrotal mass. Electron microscopy revealed features consistent with immature adipocytes, and cytogenetic analysis revealed the following karyotype: 57,XY,+4,+6,+7,der(8)t(8;12) (q22;q13), +der(8)t(8;12) (q22;q13), +9,+10,+12,-16,+17,+der(18)t(8;18)(q22;q23),+19,+20. Interestingly, the breakpoint on chromosome 12 (q13) is the same as that seen in lipoblastomas. To our knowledge, this is the first reported case of such a complex karyotype in lipoblastoma and adds to the expanding list of karyotypic abnormalities seen in such tumors.     

Cardiobacterium hominis endocarditis: two cases and a review of the literature

Cardiobacterium hominis, a member of the HACEK group (Haemophilus parainfluenzae, Haemophilus aphrophilus, and Haemophilus paraphrophilus, Actinobacillus actinomycetemcomitans, C. hominis, Eikenella corrodens, and Kingella species), is a rare cause of endocarditis. There are 61 reported cases of C. hominis infective endocarditis in the English-language literature, 15 of which involved prosthetic valve endocarditis. There is one reported case of C. hominis after upper endoscopy and none reported after colonoscopy. Presented here are two cases of C. hominis prosthetic valve endocarditis following colonoscopy and a review of the microbiological and clinical features of C. hominis endocarditis. Patients with C. hominis infection have a long duration of symptoms preceding diagnosis (138±128 days). The most common symptoms were fever (74%), fatigue/malaise (53%), weight loss/anorexia (40%), night sweats (24%), and arthralgia/myalgia (21%). The most common risk factors were pre-existing cardiac disease (61%), the presence of a prosthetic valve (28%), and history of rheumatic fever (20%). Of the 61 cases reviewed here, the aortic valve was infected in 24 (39%) and the mitral valve in 19 (31%) patients. The average duration of blood culture incubation before growth was detected was 6.3 days (range, 2–21 days). Complications were congestive heart failure (40%), central nervous system (CNS) emboli (21%), arrhythmia (16%), and mycotic aneurysm (9%). C. hominis is almost always susceptible to β-lactam antibiotics. Ceftriaxone is recommended by the recently published American Heart Association guidelines. The prognosis of C. hominis native valve and prosthetic valve endocarditis is favorable. The cure rate among 60 patients reviewed was 93% (56/60). For prosthetic valve endocarditis, the cure rate was 16/17 (94%). Valve replacement was required in 27 (45%) cases.     

Choroid plexus tumours: cytogenetic analysis of a single case and literature review

Choroid plexus tumours are intraventricular papillary lesions that are observed in typical papillomas, atypical papillomas and carcinomas. They usually occur in childhood, and can result in hydrocephalus and increased intracranial pressure. The present paper describes a case of choroid plexus papilloma in an adult woman; cytogenetic analysis of the lesion is also presented, which demonstrated the presence of tumour mosaicism. Compared to the chromosomal aberrations observed in previous cases, those in the present tumour do not show significant differences between papillomas harboured in adults and paediatric patients. Moreover, there was no apparent correlation between genetic alternations in typical and atypical papillomas and prognosis or recurrence.     

Characterization of a supernumerary ring chromosome 1 mosaicism in two cell systems by molecular cytogenetic techniques and review of the literature

We report on a 4-year-old boy with developmental delay and microcephaly with an additional small marker chromosome derived from chromosome 1 and detected in 14% of T-lymphocytes by conventional cytogenetics and in 9% of buccal smear cells by interphase FISH. Using molecular cytogenetic techniques, the marker chromosome was characterized as an extra ring chromosome consisting of euchromatic material from the proximal short arm of chromosome 1. We compare the cytogenetic data and the phenotype of our patient to those previously described cases with marker chromosome 1 mosaicism. We conclude that in addition to the straightforward molecular cytogenetic characterization of the euchromatic content of the ring chromosome, the investigation of a second cell system gives additional information about the tissue specific distribution of the supernumerary marker chromosome (SMC) and provides more reliable data for further karyotype/phenotype correlations and the prediction of the phenotypic outcome in prenatal cases.