Cutaneous leiomyosarcoma arising in a smallpox scar.

BACKGROUND: Cutaneous leiomyosarcoma (CLM) is a very rare smooth muscle tumour that accounts for about 2-3% of all superficial soft tissue sarcomas. Although the development of various malignancies in scar tissue is well known, we report the first case of a CLM developing in a small pox scar. CASE PRESENTATION: A 66-year-old man presented with a painless, slow-growing lump in a small pox scar on his left shoulder. Histological biopsies showed the lesion to be a primary, well-differentiated cutaneous leiomyosarcoma. A CT scan of the thorax was conducted, which showed no signs of metastases. The complete lesion was then surgically excised, and histopathological examination revealed a radically excised cutaneous type leiomyosarcoma After 13 months' review the patient was doing well with no evidence of tumour recurrence. CONCLUSIONS: This is the first report of a CLM arising in a small pox scar. Although the extended time interval between scarring and malignant changes makes it difficult to advise strict follow-up for patients with small pox scars, one should be aware that atypical changes and/or symptoms occurring in a small pox scar could potentially mean malignant transformation.

An immunohistochemical procedure to detect patients with paraganglioma and phaeochromocytoma with germline SDHB, SDHC, or SDHD gene mutations: a retrospective and prospective analysis.

BACKGROUND: Phaeochromocytomas and paragangliomas are neuro-endocrine tumours that occur sporadically and in several hereditary tumour syndromes, including the phaeochromocytoma-paraganglioma syndrome. This syndrome is caused by germline mutations in succinate dehydrogenase B (SDHB), C (SDHC), or D (SDHD) genes. Clinically, the phaeochromocytoma-paraganglioma syndrome is often unrecognised, although 10-30% of apparently sporadic phaeochromocytomas and paragangliomas harbour germline SDH-gene mutations. Despite these figures, the screening of phaeochromocytomas and paragangliomas for mutations in the SDH genes to detect phaeochromocytoma-paraganglioma syndrome is rarely done because of time and financial constraints. We investigated whether SDHB immunohistochemistry could effectively discriminate between SDH-related and non-SDH-related phaeochromocytomas and paragangliomas in large retrospective and prospective tumour series. METHODS: Immunohistochemistry for SDHB was done on 220 tumours. Two retrospective series of 175 phaeochromocytomas and paragangliomas with known germline mutation status for phaeochromocytoma-susceptibility or paraganglioma-susceptibility genes were investigated. Additionally, a prospective series of 45 phaeochromocytomas and paragangliomas was investigated for SDHB immunostaining followed by SDHB, SDHC, and SDHD mutation testing. FINDINGS: SDHB protein expression was absent in all 102 phaeochromocytomas and paragangliomas with an SDHB, SDHC, or SDHD mutation, but was present in all 65 paraganglionic tumours related to multiple endocrine neoplasia type 2, von Hippel-Lindau disease, and neurofibromatosis type 1. 47 (89%) of the 53 phaeochromocytomas and paragangliomas with no syndromic germline mutation showed SDHB expression. The sensitivity and specificity of the SDHB immunohistochemistry to detect the presence of an SDH mutation in the prospective series were 100% (95% CI 87-100) and 84% (60-97), respectively. INTERPRETATION: Phaeochromocytoma-paraganglioma syndrome can be diagnosed reliably by an immunohistochemical procedure. SDHB, SDHC, and SDHD germline mutation testing is indicated only in patients with SDHB-negative tumours. SDHB immunohistochemistry on phaeochromocytomas and paragangliomas could improve the diagnosis of phaeochromocytoma-paraganglioma syndrome. FUNDING: The Netherlands Organisation for Scientific Research, Dutch Cancer Society, Vanderes Foundation, Association pour la Recherche contre le Cancer, Institut National de la Santé et de la Recherche Médicale, and a PHRC grant COMETE 3 for the COMETE network.

Clinical characteristics of pheochromocytoma patients with germline mutations in SDHD.

PURPOSE: We examined the value of SDHD mutation screening in patients presenting with apparently sporadic and familial pheochromocytoma for the identification of SDHD-related pheochromocytomas. PATIENTS AND METHODS: This retrospective study involved 126 patients with adrenal or extra-adrenal pheochromocytomas, including 24 patients with a family history of multiple endocrine neoplasia 2, von Hippel-Lindau disease, neurofibromatosis type 1, or paraganglioma (PGL). Conformation-dependent gel electrophoresis and sequence determination analysis of germline and tumor DNA were used to identify SDHD alterations. The clinical and molecular characteristics of sporadic and hereditary tumors were compared. We reviewed the literature and compared our results with those from previously published studies. RESULTS: Pathogenic germline SDHD mutations were identified in three patients: two (2.0%) of the 102 apparently sporadic pheochromocytoma patients and one patient with a family history of PGL. These patients presented with multifocal disease (two of three multifocal patients) or with a single adrenal tumor (one of 82 patients). In the literature, mutations are mostly found in patients

Frequent germ-line succinate dehydrogenase subunit D gene mutations in patients with apparently sporadic parasympathetic paraganglioma.

PURPOSE: Recently, familial paraganglioma (PGL) was shown to be caused bymutations in the gene encoding succinate dehydrogenase subunit D (SDHD). However, the prevalence of SDHD mutations in apparently sporadic PGL is unknown. We studied the frequency and spectrum of germ-line and somatic SDHD mutations in patients with parasympathetic PGL. EXPERIMENTAL DESIGH: We studied 57 unselected patients who developed parasympathetic PGLs (n = 105 tumors) and who were treated between 1987 and 1999 at the Erasmus MC (Rotterdam, the Netherlands). Thirty-eight (67%) of these patients (n = 51 tumors) lacked a family history of parasympathetic PGL. We used conformation-dependent gel electrophoresis and sequence determination analysis of germ-line and tumor DNA to identify SDHD mutations. We compared the clinical and molecular characteristics of sporadic and hereditary PGLs. RESULTS: Three different SDHD germ-line mutations were identified in 32 of the 57 (56%) patients. These included 19 of 19 (100%) patients with familial PGL and also 13 of 38 (34%) patients with apparently sporadic PGL. All three mutations were characterized as missense mutations (D92Y, L95P, and L139P) in highly conserved regions of the SDHD gene and were not observed in 200 control alleles. No somatic mutations were found. CONCLUSIONS: Germ-line mutations of the SDHD gene are present in a significant number of patients with apparently sporadic parasympathetic PGL. Somatic SDHD mutations do not play a significant role in the sporadic form of this tumor. Genetic testing for SDHD germ-line mutations should be considered for every patient presenting with this tumor, even if a personal or family history of PGL is absent, to allow appropriate clinical management.

Molecular genetic alterations in adrenal and extra-adrenal pheochromocytomas and paragangliomas.

Pheochromocytomas and paragangliomas are neuroendocrine neoplasias of neural crest origin. Genetic mutations that are characterized in other human neoplasms are rarely seen in these tumors. About 10% of the patients with pheochromocytomas and paragangliomas present with a family history of von Hippel-Lindau disease (VHL), Multiple endocrine neoplasia type 2 (MEN2), one of the three familial paraganglioma syndromes (PGL; PGL1, PGL3, PGL4), or neurofibromatosis type 1 (NF1). In an even higher percentage, a genetic predisposition is involved in the development of these tumors. The genes of hereditary tumor syndromes such as the aforementioned ones are also ideal to study the molecular pathogenesis in the sporadic counterparts. Many studies have been undertaken to identify important secondary genetic events that contribute to the tumorigenesis of pheochromocytoma or paraganglioma, but a comprehensive review of these data is lacking. Recent findings of CGH and LOH studies provided new starting points to unravel the pathogenesis and progression of these tumors. This review presents an overview of our current understanding of the molecular pathogenesis of pheochromocytoma and paraganglioma.

Frequent loss of 17p, but no p53 mutations or protein overexpression in benign and malignant pheochromocytomas.

Genetic changes in the tumorigenesis of sporadic pheochromocytomas are poorly understood, and there are no good markers to discriminate benign from malignant pheochromocytomas. p53 is a tumor suppressor gene and aberrations in this gene are frequently found in many tumor types. The role of p53 in pheochromocytoma tumorigenesis is unclear, with some studies suggesting that p53 mutations can be used to discriminate benign from malignant pheochromocytomas while other studies do not find such an association. Because most of these investigations were hampered by small series of tumors and the use of varying methods, we have performed a comprehensive analysis of p53 aberrations in a large series of pheochromocytomas. Comparative genomic hybridization analysis of 31 benign and 20 malignant tumors showed loss of the p53 locus at chromosome 17p13.1 in 23/51 (45%) cases, and most of these results were confirmed by fluorescence in situ hybridization. Forty-three tumors, including the malignant tumors and the tumors with loss of the p53 locus, were analyzed for p53 mutations in exons 5-8, but none were found. Furthermore, p53 immunohistochemistry on 35 cases revealed strong nuclear p53 expression in only two pheochromocytoma metastases, all other tumors being negative. We conclude that, although there is frequent loss of the p53 locus on 17p, the p53 gene does not appear to play a major role in pheochromocytoma tumorigenesis.

Microarray-based CGH of sporadic and syndrome-related pheochromocytomas using a 0.1-0.2 Mb bacterial artificial chromosome array spanning chromosome arm 1p.

Pheochromocytomas (PCC) are relatively rare neuroendocrine tumors, mainly of the adrenal medulla. They arise sporadically or occur secondary to inherited cancer syndromes, such as multiple endocrine neoplasia type II (MEN2), von Hippel-Lindau disease (VHL), or neurofibromatosis type I (NF1). Loss of 1p is the most frequently encountered genetic alteration, especially in MEN2-related and sporadic PCC. Previous studies have revealed three regions of common somatic loss on chromosome arm 1p, using chromosome-based comparative genomic hybridization (CGH) and LOH analysis. To investigate these chromosomal aberrations with a higher resolution and sensitivity, we performed microarray-based CGH with 13 sporadic and 11 syndrome-related (10 MEN2A-related and 1 NF1-related) tumors. The array consisted of 642 overlapping bacterial artificial chromosome (BAC) clones mapped to 1p11.2-p36.33. Chromosomal deletions on 1p were detected in 18 of 24 cases (75%). Among 9 tumors with partial 1p loss, the deleted region was restricted to 1cen-1p32.3 in six cases (25%), indicating a region of genetic instability. The consensus regions of deletion in this study involved 1cen-1p21.1, 1p21.3-1p31.3, and 1p34.3-1p36.33. In conclusion, these data strongly suggest that chromosome arm 1p is the site for multiple tumor suppressor genes, although the potential candidate genes CDKN2C and PTPRF/LAR are not included in these regions.

p53 alterations and their relationship to SDHD mutations in parasympathetic paragangliomas.

Experimental and observational evidence suggests that chronic hypoxic stimulation can induce parasympathetic paraganglioma. This is emphasized by the identification of germline mutations in genes of the mitochondrial succinate dehydrogenase enzyme complex II in hereditary paraganglioma. Because of inactivating mutations in the succinate dehydrogenase subunit B (SDHB), C (SDHC), or D (SDHD) gene, the paraganglia undergo a chronic hypoxic stimulus leading to proliferation of the paraganglionic cells. Hypoxia is a known inducer of p53 up-regulation, which triggers cell cycle arrest and apoptosis. Inactivation of the p53 pathway, by gene mutation or by MDM2 overexpression, would enable cells to escape from cell cycle arrest and apoptosis and could contribute to tumorigenesis. To determine whether p53 inactivation plays a role in paraganglioma tumorigenesis, we investigated a series of 43 paragangliomas from 41 patients (of whom 24 patients harbored a germline SDHD mutation) for mutations in p53 exons 5-8 by PCR-SSCP. In addition, these tumors were investigated for p53 and MDM2 protein expression by immunohistochemistry, and the results were compared with clinical data and the presence of SDHD mutations. No aberrations in p53 exons 5-8 were found. The immunohistochemical experiments showed nuclear p53 expression in 15 tumors. Three tumors were positive for MDM2 that were also positive for p53. There was no correlation between p53 and MDM2 expression and clinical data or SDHD status. Given the fact that hypoxia induces p53 expression and regarding the absence of p53 mutations, these results suggest that p53 inactivation does not play a major role in the tumorigenesis of hereditary and sporadic paragangliomas.

Von Hippel-Lindau gene alterations in sporadic benign and malignant pheochromocytomas.

The Von Hippel-Lindau (VHL) gene product has a wide spectrum of tissue-specific functions, and specific germline mutations are associated with clinical phenotypes in VHL disease. In particular, missense mutations are correlated with the susceptibility to pheochromocytomas. An association between VHL aberrations and prognosis has been suggested in renal clear cell carcinoma but has not been studied in pheochromocytomas. We studied the frequency and spectrum of VHL alterations in apparently sporadic pheochromocytomas in relation to the clinical behavior in 72 patients, including 48 patients with clinically benign and 24 patients with malignant pheochromocytomas. Single-strand conformation polymorphism (SSCP) analysis followed by DNA sequencing, loss of heterozygosity analysis of the VHL locus and immunohistochemistry for VHL protein expression were used to investigate somatic VHL gene alterations. In 2 patients, 1 with a malignant tumor, germline mutations were identified in the stop codon. Tumor-specific intragenic VHL mutations and accompanying loss of heterozygosity were identified in 2 (4.3%) of 47 sporadic benign pheochromocytomas compared to 4 (17.4%) of 23 malignant tumors (p = 0.064). Only one of these mutations has been previously described, in a renal clear cell carcinoma. Expression of the VHL protein was observed in all pheochromocytomas. No distinction in the nature of VHL alterations between benign and malignant pheochromocytomas and no correlation with histopathologic or clinical features was observed. We report novel VHL mutations in sporadic pheochromocytomas, which are slightly correlated with malignancy. VHL mutations may have some impact on the malignant transformation of pheochromocytomas.