Recombinations of chromosomal bands 6p21 and 14q24 characterise pulmonary hamartomas

Unusual Anterior Mediastinal Tumors Treated at a Tertiary Thoracic Center: A Case Series Analysis

Several tumors arise from different structures within the mediastinum. Although each type of mediastinal tumor has a predilection for a specific compartment, the progression of growth from one compartment to another can occur. The anterior mediastinum is the site of several tumors that pose interesting diagnostic and therapeutic challenges to thoracic surgeons. The anterior mediastinum is the seat of the majority of neoplastic growths within the mediastinum. Thymomas and lymphomas are the most common pathologies of the anterior mediastinum. Tumors of mesenchymal origin (hemangioma, lymphangioma, lipomas) and their malignant counterparts may occur in any of the mediastinal compartments. Less common tumors of the anterior mediastinal compartment are ectopic thyroid and parathyroid tumors, germ cell tumors, mesenchymal origin tumors, hemangiomas, and cervicomediastinal hygromas. Most of the mediastinal growths usually remain clinically silent until they become large and cause compressive symptoms. Here, we present a case series of five anterior mediastinal tumors consisting of solitary benign teratoma, fibrous benign tumor, malignant fibrosarcoma, hamartomatous chondroma, and malignant thymoma.

Clinical, Radiologic, and Pathologic Characteristics of Pulmonary Hamartomas With Uncommon Presentation

OBJECTIVES

To investigate the clinicopathologic and radiologic features of pulmonary hamartomas (PHs) with uncommon clinical presentation.

METHODS

A retrospective clinicopathologic and radiologic review was performed for patients diagnosed (1999-2019) with multiple hamartomas, lesions arising adjacent to a coexisting pulmonary malignancy, and tumors with predominantly extrapulmonary localization.

RESULTS

Of 979 patients diagnosed with PHs, 6 (0.6%) had multiple hamartomas, 4 (0.4%) had hamartomas adjacent to lung adenocarcinoma, and 2 (0.2%) had large mediastinal masses. Patients with multiple lesions had a median age of 65 years and mean tumor size of 0.9 cm; 1 patient had 3 hamartomas, and 5 patients had 2. Lesions next to adenocarcinomas had a mean size of 1.4 cm, and affected patients had a median age of 69 years. Predominantly mediastinal PHs, diagnosed in a 63-year-old woman and a 68-year-old man, measured 4.1 to 6 cm and were connected to the lung. All lesions were solid on imaging with absence of definitive fat or calcification, concerning for granuloma or malignancy. All cases had typical histology of PH, although one of the mediastinal tumors had an unusual amount of epithelial hyperplasia.

CONCLUSIONS

PHs can be clinically and radiologically challenging to diagnose. Histopathologic examination of biopsies and resection specimens is diagnostically crucial in this setting.

Benign tumours of the bronchopulmonary system

The vast majority of tumours arising in the bronchopulmonary system are malignant in nature. Benign tumours of the lung are relatively rare and are often incidental findings during clinical investigations for unrelated conditions. These lesions can arise in the bronchial tree or the pulmonary parenchyma and may be of epithelial, mesenchymal, salivary gland-type or unknown differentiation. Although the spectrum of these lesions is wide, the clinical, pathological and immunohistochemical characteristics of the most relevant will be the subject of this review. In addition, the most important features allowing differentiation from malignant pulmonary neoplasms will be discussed.

Anaesthetic management of a patient with eosinophilic granulomatosis with polyangiitis for internal fixation of a fractured femur

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare disease with an estimated annual incidence of 0.5-6.8 per million. It is characterised by necrotising vasculitis with multiorgan eosinophilic infiltration. Pulmonary manifestations are the most common presentation of EGPA, and cardiac complications are the most common cause of death. Anaesthetic management of EGPA is challenging due to perioperative pulmonary complications, multiorgan involvement and greater risk of cholinesterase enzyme deficiency. We are reporting the anaesthetic management of a 58-year-old woman, diagnosed with EGPA 3 years ago, who underwent urgent intramedullary nail insertion for a femur fracture. The anaesthetic technique comprised femoral nerve block and spinal anaesthesia, thereby avoiding (1) the need for upper airway manipulation, (2) potential adverse effects of anticholinesterase drugs (for reversal of neuromuscular blockade) and (3) histamine release associated with morphine administration perioperatively. Surgery and anaesthesia were uneventful.

Cryodebulking of endobronchial hamartoma via fibreoptic bronchoscopy and literature review

Endobronchial hamartoma is a rare tumour. We report a 65-year-old woman with a history of recurrent pneumonia. Bronchoscopy revealed a 1 cm endobronchial mass obstructing the left upper lobe bronchus. Histopathological examination was consistent with a pulmonary hamartoma. This lesion was successfully debulked endoscopically with the use of a flexible cryoprobe without any complications. This case highlights both the importance of investigating recurrent pneumonia and the usefulness of endoscopic recanalisation in an obstructed segmental bronchus.

Pulmonary giant chondromatous hamartoma with multifocal evolution in an infant

Hamartoma is the most common benign pulmonary tumor in adults, but is rarely described in the pediatric population. Giant chondromatous and progressive forms are even rarer. We report the novel case of a 13-month-old infant hospitalized for giant pulmonary chondromatous hamartoma discovered during a septic episode, rapidly progressive, with severe multifocal lesions, without clear response to several cytotoxic therapies. No predisposition syndrome was identified.

Incidental endobronchial hamartoma in a patient with enchondroma

Hamartomas are the most common type of benign tumours of the lung, constituting a small portion of all lung neoplasms. Hamartomas are rare benign tumours composed of multiple mesenchymal cell lines. Two clinical types have been defined according to the location: intraparenchymal and endobronchial, more frequently the former. We present a case of endobronchial hamartoma causing significant blockage of the right middle lobe. The finding was incidental on a CT scan of the chest done for staging purposes for a large mixed lytic and sclerotic lesion that was found within the proximal-mid portion of the tibial diaphysis. The endobronchial lesion was removed by hot electrocautery snare during bronchoscopy and identified as a hamartoma. Argon plasma coagulation was applied to the lesion's base afterwards and the patient was to follow-up in 3 months for a repeat CT scan.

Extralobar Sequestration Complicated by a Cystic Hamartoma in an Adult

A 49-year-old woman presented after a respiratory infection with an abnormal chest roentgenogram demonstrating a cystic calcified mass at the base of the right lung. A chest computed tomographic angiogram demonstrated that the blood supply arose from the abdominal aorta. This extralobar sequestration was surgically resected using video-assisted thoracoscopy without complication. The pathology report showed a cystic hamartoma. This case highlights the importance of preoperative evaluation of the blood supply of suspected sequestrations and the very rare disorder that was found.

Hamartomas and other tumor-like malformations of the lungs and heart

Tumor-like malformative lesions are seen throughout the body, and they may be confused with true neoplasms by clinicians and pathologists alike. In the lungs, they are principally represented by hamartomas-which may contain chondroid, adipocytic, fibroblastic, and myxoid tissue, with entrapped bronchiolar epithelium-and congenital pulmonary airway malformations (CPAMs). The latter have been subdivided into 5 groups, based on their histological features, but they basically comprise proliferations of malformed bronchopulmonary tissues of different types. Type 1 lesions have a capacity for malignant transformation in a small proportion of cases. Malformative cardiac tumefactions include rhabdomyoma-like hamartomas; fibromatous hamartomas; and mesenchymal ventricular hamartomas, which contain cardiac muscle, smooth muscle, fat, vasogenic tissue, and nerves. Another intracardiac proliferation in the same general category is seen in the interatrial septum, in the region of the atrioventricular node. It comprises randomly-disposed gland-like profiles that are made up of endodermal epithelium. Originally thought to be a form of mesothelial lesion, that abnormality is now classified as an endodermal choristoma. All forms of pulmonary and cardiac malformations are only rarely symptomatic, and the necessity for surgical excision of them depends on the particular details of each case.

Variable alterations of mitochondrial microsatellite instability and DNA copy number in pulmonary hamartomas

BACKGROUND

The genetic alteration of mitochondrial DNA has been regarded as an important step in the development of several human tumors.

OBJECTIVE

The purpose of this study was to identify frequency of mitochondrial microsatellite instability (mtMSI) and alterations in mitochondrial DNA copy number (mtCN) in pulmonary hamartoma.

METHODS

DNA was isolated from tumor tissue and matched non-tumor tissue in 30 patients with pulmonary hamartoma. BAT 25 and 26 were used as nucleus MSI (nMSI) markers, and (C)n and (CA)n in D-loop were used as mtMSI markers. MtCNs were quantified using a competitive quantitative real-time polymerase chain reaction.

RESULTS

nMSI was detected in 5 patients (23.8%) and mtMSI was detected in 2 patients (9.5%) of total 21 hamartoma. There were 14 patients (46.7%), 2 patients (6.7%), and a further 14 patients (46.7%) in the decreased, no change, and increased mtCN groups, respectively. The mean relative mtCN were 0.4 ± 0.3 in the decreased and 3.9 ± 5.1 in the increased mtCN groups, respectively.

CONCLUSIONS

nMSI was more frequently appeared than mtMSI in hamartomas, and we also found measurements of mtCNs in patients with pulmonary hamartoma to be extremely variable without any characteristic pattern.

A case of pulmonary hamartoma showing rapid growth

A 65-year-old man was admitted for detailed examination of a growing nodular shadow in the left lung. The nodular shadow was initially detected in a routine chest X-ray check-up in March 2012 that warranted regular chest X-ray follow-up. The nodular shadow increased in size from 12 × 15 mm to 15 × 20 mm within five months. The calculated tumor doubling time (TDT) in our case was approximately 132.2 days. A malignant tumor was strongly suspected based on the rapid growth, and tumorectomy was thus performed. Cartilaginous tissue accounted for most of the pathological specimen, but a small amount of an epithelial component was observed histologically, and we diagnosed a hamartoma. Hamartoma generally shows slow annual growth, but it is important to recognize that rapid enlargement occurs in some cases.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.

The SRY-HMG box gene, SOX4, is a target of gene amplification at chromosome 6p in lung cancer

The search for oncogenes is becoming increasingly important in cancer genetics because they are suitable targets for therapeutic intervention. To identify novel oncogenes, activated by gene amplification, we analyzed cDNA microarrays by high-resolution comparative genome hybridization and compared DNA copy number and mRNA expression levels in lung cancer cell lines. We identified several amplicons (5p13, 6p22-21, 11q13, 17q21 and 19q13) that had a concomitant increase in gene expression. These regions were also found to be amplified in lung primary tumours. We mapped the boundaries and measured expression levels of genes within the chromosome 6p amplicon. The Sry-HMG box gene SOX4 (sex-determining region Y box 4), which encodes a transcription factor involved in embryonic cell differentiation, was overexpressed by a factor of 10 in cells with amplification relative to normal cells. SOX4 expression was also stronger in a fraction of lung primary tumours and lung cancer cell lines and was associated with the presence of gene amplification. We also found variants of SOX4 in lung primary tumours and cancer cell lines, including a somatic mutation that introduced a premature stop codon (S395X) at the serine-rich C-terminal domain. Although none of the variants increased the transactivation ability of SOX4, overexpression of the wildtype and of the non-truncated variants in NIH3T3 cells significantly increased the transforming ability of the weakly oncogenic RHOA-Q63L. In conclusion, our results show that, in lung cancer, SOX4 is overexpressed due to gene amplification and provide evidence of oncogenic properties of SOX4.

Surgical treatment and outcome of pulmonary hamartoma: a retrospective study of 20-year experience

BACKGROUND

Controversy still exists in the indication and timing of surgical treatment of pulmonary hamartoma (PH). The objective of this study is to summarize the experience and the outcome of the surgical treatment for pulmonary hamartomas, and to assess the effectiveness and necessity of surgical therapy administered in patients with pulmonary hamartoma as well as clinical and pathological features and long-term follow-up results.

METHODS

This retrospective report has reviewed a 20-years clinical history of surgical treatment for 39 patients with PH from 1985 to 2006. These thirty-nine patients underwent 40 operations as follows: wedge resection (23), enucleation (10), segmentectomy (3), lobectomy (3), and pneumonectomy (1).

RESULTS

The PH occurred most frequently (78.1%) in the patients aged 40 to 60 years and the sex ratio (male/female) was 2.25/1 in our series. No postoperative death was encountered. One patient with pleural effusion was cured after thoracentesis. All of these 39 patients were proved with pathologic diagnosis of PH and the popcorn calcification was found in 6 cases before operation. In 38 cases having the mean follow-up of 7.3 years, a patient was operated thrice for regional recurrence.

CONCLUSION

Fast frozen section in operation is critical for acquire accurate pathological diagnosis. Due to potential trend of recurrence or malignancy, patients with hamartoma should be submitted to a complete evaluation and a regular follow-up.

Characterization of HKE2: an ancient antigen encoded in the major histocompatibility complex

Genes at the centromeric end of the human leukocyte antigen region influence adaptive autoimmune diseases and cancer. In this study, we characterized protein expression of HKE2, a gene located in the centromeric portion of the class II region of the major histocompatibility complex encoding subunit 6 of prefoldin. Immunohistochemical analysis using an anti-HKE2 antibody indicated that HKE2 protein expression is dramatically upregulated as a consequence of activation. In a tissue microarray and in several tumors, HKE2 was overexpressed in certain cancers compared with normal counterparts. The localization of the HKE2 gene to the class II region, its cytoplasmic expression and putative protein-binding domain suggest that HKE2 may function in adaptive immunity and cancer.

A clonal dic(16;21)(p13.1;p11.2)del(16)(q11.1), with gains of several chromosomes and monosomy 21, in a case of splenic hamartoma: evidence for its neoplastic, not hamartomatous, origin

Cytogenetic examination of a case of splenic hamartoma led to the discovery of a clonal population with the karyotype 47 approximately 58,XX,+X,+4,+5,+5,+6,+10,+12,+14,der(16)dic(16;21)(p13.3;p11.2), dic(16;21)del(16)(q11.1),+17,+19,+20,-21. This finding is indicative of a neoplastic, not hamartomatous, origin for this lesion.

Recombinations of chromosomal bands 10q24, 12q14-q15, and 14q24 in two cases of pulmonary chondroid hamartoma studied by fluorescence in situ hybridization

Pulmonary chondroid hamartomas (PCH) are benign mesenchymal tumors consisting of at least two cytogenetic subgroups. These subgroups are defined by chromosomal alterations at either 12q14-q15 or 6p21. Cytogenetic analysis of short-term cultures from two PCHs revealed two different rearrangements with 12q14 -q15. One of these had a unique translocation t(12;14)(q14-15;q24) with presence of two normal chromosomes 12 and a der(14), but missing the der(12). The other showed a complex rearrangement between chromosomes 10 and 12 with two different derivatives. Our data have been confirmed with fluorescence in situ hybridization analysis. These cases represent variant forms of the standard translocations.

Epithelial and soft tissue tumors of the tracheobronchial tree

This article provides a broad overview of tumors that can involve the tracheobronchial tree. For the most part, the clinical, radiographic, and endoscopic presentation of these rare tumors does not differ significantly from the more common tumors of the lung. Appropriate classification of many tracheobronchial tumors ultimately requires complete sampling and a thorough microscopic evaluation. The introduction of ancillary diagnostic techniques such as immunohistochemistry and molecular analysis will continue to refine tumor classification.

Construction of a high-resolution 2.5-Mb transcript map of the human 6p21.2-6p21.3 region immediately centromeric of the major histocompatibility complex

We have constructed a 2.5-Mb physical and transcription map that spans the human 6p21.2-6p21.3 region and includes the centromeric end of the MHC, using a combination of techniques. In total 88 transcription units including exons, cDNAs, and cDNA contigs were characterized and 60 were confidently positioned on the physical map. These include a number of genes encoding nuclear and splicing factors (Ndr kinase, HSU09564, HSRP20); cell cycle, DNA packaging, and apoptosis related [p21, HMGI(Y), BAK]; immune response (CSBP, SAPK4); transcription activators and zinc finger-containing genes (TEF-5, ZNF76); embryogenesis related (Csa-19); cell signaling (DIPP); structural (HSET), and other genes (TULP1, HSPRARD, DEF-6, EO6811, cyclophilin), as well as a number of RP genes and pseudogenes (RPS10, RPS12-like, RPL12-like, RPL35-like). Furthermore, several novel genes (a Br140-like, a G2S-like, a FBN2-like, a ZNF-like, and B1/KIAA0229) have been identified, as well as cDNAs and cDNA contigs. The detailed map of the gene content of this chromosomal segment provides a number of candidate genes, which may be involved in several biological processes that have been associated with this region, such as spermatogenesis, development, embryogenesis, and neoplasia. The data provide useful tools for synteny studies between mice and humans, for genome structure analysis, gene density comparisons, and studies of nucleotide composition, of different isochores and Giemsa light and Giemsa dark bands.

Characterization of a chromosomally complex lung cancer cell line using multiwell fluorescence in situ hybridization

The chromosomal characterization of a non-small cell lung cancer cell line (NCIH358) is described. This characterization was achieved using a simple, cheap and technically straightforward multiwell fluorescence in situ hybridization (FISH) method. The many and complex chromosome rearrangements identified by this method could not be defined using conventional G-banded chromosome analysis, and have not been previously described. For the detailed characterization of complex cell lines, multiwell FISH has many advantages over more technically demanding and expensive FISH techniques, and opens up the possibility of screening for consistent rearrangements, leading to the identification of unique fusion genes.

hREC2, a RAD51-like gene, is disrupted by t(12;14) (q15;q24.1) in a uterine leiomyoma

A balanced translocation between chromosomes 12 and 14 is commonly seen in uterine leiomyoma (UL). We have previously cloned and characterized a 2 Mb segment of human chromosomal subband 14q24.1, and have shown that the t(12;14)(q15;q24.1) breakpoints from several ULs map within this region. Exon trapping of DNA clones spanning one such breakpoint revealed coding sequences from hREC2, a gene that shows significant amino acid sequence identity to the double-strand break repair enzyme RAD51. We report here that this breakpoint is located within a 19 kb intron of the hREC2 gene and that the translocation results in the premature truncation of the major hREC2 transcript. Mapping and sequence analyses show that alternative transcripts of the hREC2 gene, including novel isoforms identified in testis and uterus, are not interrupted by the translocation.

Genomic and functional map of the chromosome 14 t(12;14) breakpoint cluster region in uterine leiomyoma

A translocation involving chromosomes 12 and 14 [t(12;14)(q15;24.1)] is commonly seen in benign smooth muscle tumor as uterine leiomyoma (UL). A contig of P1-derived artificial chromosome and bacterial artificial chromosome clones on chromosome 14, encompassing a t(12;14) breakpoint cluster region (BCR) in UL, was generated principally using the recently developed HAPPY map of chromosome 14 as a framework (P. H. Dear et al., 1998, Genomics 48: 232-241). Three UL t(12;14) breakpoints have been localized within this contig, showing that a BCR of at least 400 kb exists on chromosome 14. Other studies of tumors with t(12;14) rearrangements similarly show breakpoints within a 475-kb multiple aberration region on chromosome 12. Thus t(12;14) is an example of a translocation in which the breakpoints are located within a BCR on both chromosome 12 and chromosome 14, justifying the identification of expressed sequences that are altered in these BCR regions. A total of four expressed sequences were identified in the BCR on chromosome 14. Two of these were novel cDNAs (D14S1460E and D14S1461E). The chromosome 14 cDNAs were expressed in multiple adult tissues. The identification of a large breakpoint cluster region on chromosome 14 suggests that translocations in this region mediate their effects at a distance and also that elements that predispose this region to recurrent chromosomal translocation may be widely distributed.

Physical map of human 6p21.2-6p21.3: region flanking the centromeric end of the major histocompatibility complex

We have physically mapped and cloned a 2.5-Mb chromosomal segment flanking the centromeric end of the major histocompatibility complex (MHC). We characterized in detail 27 YACs, 144 cosmids, 51 PACs, and 5 BACs, which will facilitate the complete genomic sequencing of this region of chromosome 6. The contig contains the genes encoding CSBP, p21, HSU09564 serine kinase, ZNF76, TCP-11, RPS10, HMGI(Y), BAK, and the human homolog of Tctex-7 (HSET). The GLO1 gene was mapped further centromeric in the 6p21.2-6p21.1 region toward TCTE-1. The gene order of the GLO1-HMGI(Y) segment in respect to the centromere is similar to the gene order in the mouse t-chromosome distal inversion, indicating that there is conservation in gene content but not gene order between humans and mice in this region. The close linkage of the BAK and CSBP genes to the MHC is of interest because of their possible involvement in autoimmune disease.

Cloning of a breakpoint cluster region on chromosome 14 in uterine leiomyoma

A recurrent reciprocal chromosomal translocation, t(12;14)(q15;q24) is frequently observed in uterine leiomyoma. Chromosome 12 breakpoints have been shown to occur in a region of approximately 150 kb that contains the gene for a high mobility group protein (HMGI-C). The breakpoint region on chromosome 14 has not been precisely defined. We have generated a contig of overlapping yeast artificial chromosome (YAC) clones approximately 3 Mb in size. Fluorescence in situ hybridization (FISH) analysis showed that this contig spanned the t(12;14) breakpoints in three uterine leiomyomas and that the breakpoints in these tumors occurred within a 1 Mb region. A 30 kb cosmid spanning one of the breakpoints was isolated to set the stage for identifying regions on chromosome 14 that may cause this region to be a preferential site for chromosomal translocation.

Endobronchial lipomatous hamartoma: a rare cause of bronchial occlusion

A 74-year-old man presented with shortness of breath and vague chest pain. A chest roentgenogram showed subtotal atelectasis of the upper lobe of the left lung and a CT scan revealed an occlusion of the bronchus of the upper lobe of the left lung by an intraluminal tumor. A well-circumscribed yellow tumor obstructing the bronchus of the upper lobe of the left lung was seen by fiberoptic bronchoscopy. Biopsies revealed mature fat tissue and small areas with bone consistent with the diagnosis of an endobronchial predominantly lipomatous hamartoma.

Chromosomal abnormalities in low grade chondrosarcoma and a review of the literature

In this study, cytogenetic analysis of two low-grade chondrosarcomas revealed relatively simple chromosomal complements with structural rearrangements involving chromosomes 1, 6, and 12 [46,XY,add(16)(q24)[3]/46,XY,t(1;20)(q21;q11),t(6;17)(q23;q23)[3]/46,XY, t(4;14)(q12;q24),t(5;6)(q12;p21) [2] and 45,XY,t(12;16)(q13;q24),-14[17]/44,idem,add(4)(p16),-17,[2] respectively]. Previously published reports of chondrosarcoma have revealed structural abnormalities of chromosomes 1, 6, 9, 12, and 15 as common. Also, a correlation between the simplicity or complexity of the abnormalities seen and histologic grade has been suggested. The findings of the current study support these earlier observations.

Clinical significance of cytogenetic findings in solid tumors

Chromosome analysis of solid tumors is becoming an increasingly useful tool to help establish a correct diagnosis and to provide prognostically important information. Characteristic karyotypic patterns in terms of degree of cytogenetic complexity and type of nonrandom abnormalities may help to distinguish neoplasia from a nonneoplastic lesion and to differentiate between a benign and a malignant tumor. More importantly, the presence of a specific or pathognomonic change may confirm or refute a suspected diagnosis, provide an alternative, unsuspected diagnosis, and trace the origin of a metastasis. Presently, specific cytogenetic abnormalities may be of substantial, and sometimes decisive, help in four groups of differential diagnostic dilemmas: (1) Benign vs. malignant epithelial tumors of the kidney, thyroid gland, salivary glands, and ovary; (2) Benign vs. malignant mesenchymal tumors of adipose and muscle tissue; (3) Differentiation between various malignant bone and soft tissue tumors: and (4) Diagnosis of undifferentiated small-cell round-cell tumors. In addition to the diagnostic value, karyotypic findings may provide prognostic information. Thus, the presence of an abnormal clone and/or complex rearrangements is a poor prognostic sign in, e.g., carcinomas of the ovary, prostate, bladder, colon, and pancreas. Furthermore, characteristic cytogenetic aberrations are now known to be valuable prognostic parameters in malignant melanoma, malignant fibrous histiocytoma, germ cell tumors, neuroblastoma, and squamous cell carcinoma of the head and neck region. Many of the correlation analyses are preliminary, but they all point in the same direction, namely that cytogenetic studies will soon play the same essential role in the management of patients with solid tumors as they do today in hematologic oncology.

HMGI(Y) activation by chromosome 6p21 rearrangements in multilineage mesenchymal cells from pulmonary hamartoma

The chromosome band 6p21 high-mobility group gene, HMGI(Y), encodes DNA-binding proteins with both chromatin structural and gene regulatory roles. Although HMGI(Y) expression is associated with neoplastic transformation, no oncogenic HMGI(Y) mutations have been identified. We report pulmonary chondroid hamartoma chromosome 6p21 aberrations targeting HMGI(Y). Several pulmonary chondroid hamartomas had chromosome rearrangements mapping within 100 kb of HMGI(Y), and one pulmonary chondroid hamartoma contained an intragenic fusion juxtaposing HMGI(Y) A.T book DNA-binding domains with a laminin alpha 4 chain epidermal-growth-factor-like/ zinc-finger-like motif. These findings demonstrate an oncogenic role for HMGI(Y) and for laminin chain transcriptional regulatory motifs.

Chromosome rearrangements in synovial chondromatous lesions

Short-term cultures from one synovial chondroma and three cases of synovial chondromatosis, a lesion for which no previous karyotypic information exists, were cytogenetically analysed. Whereas the chondroma displayed the relatively simple karyotype 46,XY,add(12)(q13),der(17)t(12;17)(q13;q21), more complex changes were found in the three cases of chondromatosis: case 1, 47,XY,der(1)inv(1)(p13q25)del (1)(q25q32), t(1;12)(q25;q13), + 5,der(12)add(12)(p11)t(1;12)(p22;q13); case 2, 47,XY,add(10)(q26), + 20/46 idem,-6/46,XY,t(2;4)(q33;q21), add(21)(p11); and case 3, 44,XY,add(1)(p36), del(1)(p13p22),add(6)(p25), del(7) (q22q32),del(10)(q21),add(11)(q13),-17,-18. The cytogenetic findings strongly suggest that synovial chondro-matosis is a clonal proliferation. Apart from a near-diploid chromosome number, the only recurrent cytogenetic features among the four cases were loss of band 10q26 and rearrangements of 1p13 and 12q13, found in two cases each. While chromosome bands 1p13 and 10q26 have not been reported to be involved in other types of benign chondromatous lesions, the 12q13-15 segment is recurrently rearranged in a variety of chondromatous tumours, e.g. pulmonary chondroid hamartomas. The present finding of translocations affecting band 12q13 in two of the cases emphasises that, irrespective of the anatomical localisation of the tumours, rearrangements of genes in 12q13-15 are important in the development of a large subset of benign and malignant cartilage-forming tumours.

A nonbalanced translocation (10;16) demonstrated by FISH analysis in a case of alveolar adenoma of the lung

Short-term cultures from an alveolar adenoma of the lung were cytogenetically examined. Of the 54 metaphases studied, 44 were characterized by an apparently normal karyotype and 10 showed a pseudodiploid karyotype: 46,XX,add(16)(q24). Fluorescence in situ hybridization studies permitted identification of the add(16)(q24) as a der(16)t(10;16)(q23;q24). This is the first report of a chromosomal aberration in an alveolar adenoma of the lung.

Transcriptional activation of HMGI-C in three pulmonary hamartomas each with a der(14)t(12;14) as the sole cytogenetic abnormality

Aberrations involving the chromosomal region 12q14-15 are non-random cytogenetic abnormalities in many benign tumors, e.g. pulmonary chondroid hamartomas (PCH). Recently, we identified rearrangements of the HMGI-C gene within the third or fourth intron as the molecular mechanism underlying most of these chromosomal aberrations. Herein we report our FISH and RACE studies on three PCHs each showing a rare variant type of the translocation t(12;14)(q14-15;q24) with presence of two normal chromosomes 12 and a der(14) but missing the der(12). The results revealed that in all three cases the breakpoint is located 5' to HMGI-C, suggesting that besides intragenic rearrangements also transcriptional activation of the gene can initiate tumor growth.

Structural aberrations of chromosome 6 in three uterine smooth muscle tumors

Clonal karyotypic alterations of chromosome 6 in three uterine smooth muscle tumors are reported. In all cases an apparently identical breakpoint on the short arm of chromosome 6 was found. Two cases displayed the histologic features of cell-rich myomas with severe nuclear atypia but no clear evidence for malignancy. The remaining case was a primary uterine leiomyosarcoma of an 80-year-old patient showing an apparently balanced reciprocal chromosomal translocation, t(1;6)(p32-33;p21.3), as the sole karyotypic abnormality. This type of aberration has not been reported before in leiomyosarcomas. Because of the nuclear atypia in the other myomas with a breakpoint involving the short arm of chromosome 6 we feel that this cytogenetically recognizable but rare subgroup of uterine smooth muscle tumors warrants a careful clinical follow-up.

Variant translocation t(6;10)(p21;q22) in pulmonary chondroid hamartoma

Banding cytogenetics and fluorescence in situ hybridization analysis of a pulmonary chondroid hamartoma (PHC) showed the presence of a t(6;10)(p21;q22). A cytogenetically identical translocation has previously been found in another case of PHC, suggesting that it could represent a variant form of the standard t(6;14)(p21;q24).

Pulmonary hamartomas

OBJECTIVE

To analyze the clinical and pathologic features of biopsy-proven pulmonary hamartomas at a tertiary referral center.

DESIGN

We retrospectively reviewed institutional data on pulmonary hamartomas for a 17-year study period.

MATERIAL AND METHODS

The Mayo Clinic computerized medical records database was searched for patients who had biopsy, excision, or autopsy diagnosis of pulmonary hamartomas from 1976 through 1992. Medical records and all available histologic sections were reviewed.

RESULTS

Of the 215 patients with histologically confirmed pulmonary hamartoma, 141 were men and 74 were women (approximately a 2:1 ratio). Two hundred eight patients were asymptomatic, 54 of whom were undergoing assessment for a comorbid disease process. Only four patients had new onset of respiratory symptoms. The peak incidence of occurrence was in the seventh decade of life. The mean size of the hamartomas were 1.5 cm (range, 0.2 to 6.0); no lobe was predominantly involved. Most hamartomas were resected by simple or wedge excision. Sixty-three patients (29.3%) had a concurrent neoplasm (most commonly, lung carcinoma). Follow-up ranged from 2 to 192 months (mean, 61). Eight postoperative deaths occurred. No recurrent pulmonary hamartomas developed. In one patient, lung carcinoma developed 33 months after excision of a hamartoma. In a second patient, sputum cytologic findings were abnormal 9 years later. A third patient had biopsy-proven adenocarcinoma metastatic to bone and an indeterminate lung nodule 2 years after resection of a pulmonary hamartoma.

CONCLUSIONS

Pulmonary hamartomas are benign lung neoplasms that, in our referral population occurred most commonly in asymptomatic older men. A substantial number of our patients had concurrent neoplasms; however, many had been referred for cancer treatment. We found no evidence of either a malignant transformation or an unexplained association with other lung neoplasms.

Leiomyomatous hamartoma of the posterior tongue: a case report

A case of a rare leiomyomatous hamartoma arising in the posterior tongue of a sixteen-month-old male is reported. There has been no recurrence following simple excision and presenting symptoms of choking on swallowing have resolved. Most other leiomyomatous hamartomas in the upper aerodigestive tract have been reported in Japanese patients and have involved the maxillary gingiva and hard palate.

Precise mapping of t(12;14) leiomyoma breakpoint on chromosome 14 between D14S298 and D14S540

Uterine leiomyoma is a common tumor of smooth muscle cell origin often characterized by the presence of a balanced t(12;14)(q13-15;q24.1) chromosomal translocation. This breakpoint on chromosome 14 had previously been placed between the markers SPTB and D14S77, a region estimated to span 7 cM. In this study we have used a meiotic breakpoint mapping panel to construct a high resolution genetic map of this interval. Markers that mapped within this interval were used to analyze DNA from a somatic cell hybrid containing the t(12;14) translocated chromosome. The results of this analysis localize the t(12;14) breakpoint on chromosome 14 between D14S298 and D14S540, between which no meiotic recombination was detected. This sets the stage for identifying the gene(s) disrupted by the chromosomal translocation by defining the markers that flank the translocation breakpoint.

Cytogenetic analysis of short-term cultured squamous cell carcinomas of the lung

Cytogenetic analysis of 122 primary squamous cell carcinomas of the lung revealed clonal abnormalities in 56 tumors. Karyotypes with simple numerical changes were found in 32 tumors: 45,X,-Y in 28, 47,XY,+7/45,X-Y, in two, 47,XY,+Y/45,X,-Y and 47,XY,+20/45,X,-Y in one tumor each. A super-numerary ring chromosome was the sole anomaly in two tumors. Complex structural changes were found in 22 tumors. The chromosomes most frequently involved in structural rearrangements were chromosomes 1 (15 tumors), 3, 7, and 11 (10 tumors each), 5 and 6 (nine tumors each), and 2, 8, and 12 (eight tumors each). The bands and regions most often affected were 1p11-13 and 5cen (six tumors each), 11p11, 14p11-13, 15cen, and 17p11-12 (five tumors each), and 12p13 and 13cen (four tumors each). The only recurrent changes were the whole-arm rearrangements i(5)(p10) (five tumors) and i(6)(p10), der(9;15)(q10;q10), and der(13;15)(q10;q10) (two tumors each). The most prominent genomic imbalances were, apart from losses of the Y chromosome, losses from 1p, 3p, 5q, 6q, 8p, 13p, and 14p and gains from 1q and 5p.

Cytogenetic and histologic findings in 17 pulmonary chondroid hamartomas: evidence for a pathogenetic relationship with lipomas and leiomyomas

Pulmonary chondroid hamartomas (PCH) are benign tumors that contain mesenchymal and epithelial components. In this series, we identified clonal chromosome aberrations in mesenchymal cells from 10 of 17 PCH. Chromosome band 12q15 was rearranged most frequently (N = 4), and one case had a t(12;14)(q15;q24) that was identical cytogenetically to the characteristic translocation in uterine leiomyomas. Histologic review revealed diverse mesenchymal populations, including undifferentiated cells, cartilage, adipose tissue, and smooth muscle, in most of the PCH. These findings suggest that PCH result from neoplastic transformation of a primitive mesenchymal cell that differentiates along chondroid, adipose, and smooth muscle pathways.

Casein kinase II alpha transgene-induced murine lymphoma: relation to theileriosis in cattle

Infection of cattle with the protozoan parasite Theileria parva results in a fatal lymphoproliferative syndrome that is associated with the overexpression of casein kinase II. The role of this enzyme in the pathogenesis of lymphoproliferative disorders was investigated by expressing the catalytic subunit in lymphocytes of transgenic mice. Adult transgenic mice displayed a stochastic propensity to develop lymphoma; co-expression of a c-myc transgene in addition to casein kinase II resulted in neonatal leukemia. Thus, the casein kinase II gene can serve as an oncogene, and its dysregulated expression is capable of transforming lymphocytes in a two-step pathway with c-myc.

Translocation (6;10)(p21;q22) in uterine leiomyomas

A translocation between chromosomes 6 and 10 was observed in two uterine leiomyomas. Translocation (6;10) may be important in the pathogenesis of a subgroup of uterine leiomyomas.