Multifocal alveolar hyperplasia associated with lymphangioleiomyomatosis in tuberous sclerosis

Multifocal alveolar hyperplasia associated with pulmonary lymphangioleiomyomatosis is reported in a 21-year-old woman with tuberous sclerosis. Beside the cystic lesions of lymphangioleiomyomatosis, the tomography showed nodules up to 8 mm in both upper lobes. A proliferation of type II pneumonocytes and Clara cells lining the alveolar walls in an adenoma-like pattern was observed. Nuclear atypia, mitoses and necrosis were not observed, providing evidence against multicentric bronchioloalveolar carcinoma or micronodular atypical alveolar adenomatous hyperplasia. Whereas the lymphangioleiomyomatosis lesions showed strong positivity for HMB45 and expressed oestrogen and progesterone receptors, the alveolar hyperplasia was negative for these markers as it was for carcinoembryonic antigen, p53 and MIB1 antibodies. Multifocal alveolar hyperplasia in tuberous sclerosis is probably a benign hamartomatous lesion in our case without progression on a 2-year follow-up. Its histogenesis is unknown, but is possibly related to chromosome instability.     

Multifocal alveolar hyperplasia associated with lymphangioleiomyomatosis in tuberous sclerosis

Multifocal alveolar hyperplasia associated with pulmonary lymphangioleiomyomatosis is reported in a 21-year-old woman with tuberous sclerosis. Beside the cystic lesions of lymphangioleiomyomatosis, the tomography showed nodules up to 8 mm in both upper lobes. A proliferation of type II pneumonocytes and Clara cells lining the alveolar walls in an adenoma-like pattern was observed. Nuclear atypia, mitoses and necrosis were not observed, providing evidence against multicentric bronchioloalveolar carcinoma or micronodular atypical alveolar adenomatous hyperplasia. Whereas the lymphangioleiomyomatosis lesions showed strong positivity for HMB45 and expressed oestrogen and progesterone receptors, the alveolar hyperplasia was negative for these markers as it was for carcinoembryonic antigen, p53 and MIB1 antibodies. Multifocal alveolar hyperplasia in tuberous sclerosis is probably a benign hamartomatous lesion in our case without progression on a 2-year follow-up. Its histogenesis is unknown, but is possibly related to chromosome instability.     

Multifocal micronodular pneumocyte hyperplasia and lymphangioleiomyomatosis in tuberous sclerosis with a TSC2 gene.

A 45-year-old woman with a long-standing diagnosis of tuberous sclerosis (TSC) is presented. She has multifocal micronodular pneumocyte hyperplasia (MMPH) and lymphangioleiomyomatosis (LAM) of the lung, together with the detection of TSC2 gene mutation. During surgery for spontaneous pneumothorax, an open-lung biopsy was performed. Micronodules were well defined, measuring approximately 4 mm in diameter. These MMPHs were histologically composed of papillary proliferation of Type II pneumocytes, with positive immunoreactivity of keratin and surfactant apoprotein. The cystlike spaces, with dilatation and destruction of air spaces, were diffusely formed, and the walls were composed of the spindle cells. Such LAM showed positive immunoreactivity for HMB-45 (a monoclonal antibody specific for human melanoma) and tuberin (the gene product of TSC2). On germline mutation analysis using leukocytes of the present patient, a TSC2 gene mutation was confirmed as a deletion of G (or g) on Exon 9 by polymerase chain reaction-single-strand conformational polymorphism. However, no mutation was detected in her son. With microdissection analysis using paraffin-embedding lung tissues, LOH of the TSC2 gene preliminarily was detected in a LAM lesion but not in MMPH. It is suggested that MMPH, in addition to LAM, could be another pulmonary lesion in TSC patients and that the detection of TSC2 and/or TSC1 gene could essentially be useful for the pathogenesis of MMPH and LAM in TSC patients.     

Mutational analysis of the tuberous sclerosis gene TSC2 in patients with pulmonary lymphangioleiomyomatosis

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disorder limited almost exclusively to women of reproductive age. LAM affects about 5% of women with tuberous sclerosis complex (TSC). LAM also occurs in women who do not have TSC (sporadic LAM). TSC is a tumour suppressor gene syndrome characterised by seizures, mental retardation, and tumours in the brain, heart, and kidney. Angiomyolipomas, which are benign tumours with smooth muscle, fat, and dysplastic vascular components, are the most common renal tumour in TSC. Renal angiomyolipomas also occur in 63% of sporadic LAM patients. We recently found that 54% of these angiomyolipomas have TSC2 loss of heterozygosity, leading to the hypothesis that sporadic LAM is genetically related to TSC. In this study, we screened DNA from 21 women with sporadic LAM for mutations in all 41 exons of TSC2. Twelve of the patients had known renal angiomyolipomas. No TSC2 mutations were detected. We did find three silent TSC2 polymorphisms. We conclude that patients with sporadic LAM, including those with renal angiomyolipomas, do not have a high frequency of germline mutations in the coding region of TSC2.     

Pathogenesis of multifocal micronodular pneumocyte hyperplasia and lymphangioleiomyomatosis in tuberous sclerosis and association with tuberous sclerosis genes TSC1 and TSC2

Tuberous sclerosis (TSC) is a rare, genetically determined disorder / familial tumor syndrome, currently diagnosed using specific clinical criteria proposed by Gomez, including the presence of multiorgan hamartomas. Pulmonary involvement in TSC is well known as pulmonary lymphangioleiomyomatosis (LAM), which has an incidence of 1-2.3% in TSC patients. LAM has immunohistochemical expression of both smooth-muscle actin and a monoclonal antibody specific for human melanoma, HMB-45. It has recently been reported that multifocal micronodular pneumocyte hyperplasia (MMPH) associated with TSC should be considered as a distinct type of lung lesion, whether it occurs with or without LAM. Two predisposing genes have been found in families affected by TSC; approximately half of the families show linkage to TSC1 at 9q34.3, and the other half show linkage to TSC2 at 16p13.3. TSC genes are considered to be tumor suppressor genes, and mutations in them may lead to abnormal differentiation and proliferation of cells. Tuberin, the TSC2 gene product, has recently been found to be expressed in LAM and MMPH. In this article we discuss the histogenesis and genetic abnormalities of neoplastic lesions associated with TSC, and we review the current understanding of the pathogenesis of pulmonary hamartomatous lesions such as LAM and MMPH in TSC.     

Case of tuberous sclerosis complex with pulmonary lymphangioleiomyomatosis and angiomyolipomas of the liver and kidney

A 17-year-old woman, who complained of left abdominal pain, was diagnosed as left renal bleeding by ultrasonography at emergency room in Shimane University Hospital. Further ultrasonography revealed numberless round-shaped hyperechoic liver nodules (maximum 16 mm in a diameter) and dissemination of the same type of nodules in both kidneys, which was characterized as angiomyolipomas. The lesions were also detected by abdominal CT and MRI. In addition, the findings of tuberous calcification of the cerebral ventricles and parenchyma, facial angiofibromas and shagreen patches led to the diagnosis of tuberous sclerosis complex. Since two years later, she had recurrent attacks of spontaneous pneumothorax. The histopathological examination found out lymphangioleiomyomatosis from the biopsied lung tissues. Although she became pregnant, she selected a therapeutic abortion due to the high risk for renal failure which would be induced by pressure of the grown uterine. Abdominal ultrasonography was very useful for diagnosis in this case.     

Non-penetrance in tuberous sclerosis.

Non-penetrance has not been reported in tuberous sclerosis when modern non-invasive investigations have been performed. We report a four generation family in which there was a subject with minimal expression and another with non-penetrance between a great grandfather and his great grandson. This situation highlights the need for full investigation of children of tuberous sclerosis patients before counselling a low recurrence risk for the disease.     

Uterine angiosarcoma associated with lymphangioleiomyomatosis in a patient with tuberous sclerosis complex: an autopsy case report with immunohistochemical and genetic analysis

A 41-year-old woman carrying a germline tuberous sclerosis complex 2 (TSC2) mutation, whose regular medical follow-up for tuberous sclerosis complex and tuberous sclerosis complex-associated lymphangioleiomyomatosis had continued for 2 years, had uterine angiosarcoma concomitant with uterine lymphangioleiomyomatosis. Immunohistochemically, the uterine angiosarcoma cells showed an extremely skewed lymphatic differentiation; they were diffusely immunopositive for CD31 but negative for other vascular endothelial markers including factor VIII and CD34 yet strongly immunopositive for lymphatic endothelial markers including D2-40 and Prox-1. Loss of heterozygosity analysis demonstrated that not only lymphangioleiomyomatosis and renal angiomyolipoma but also the uterine angiosarcoma had loss of heterozygosity on TSC2. Furthermore, direct sequencing revealed a TP53 mutation in the uterine angiosarcoma. Collectively, the findings suggest that combined dysfunction of the p53 and TSC2 tumor suppressor proteins may contribute to the development of uterine angiosarcoma in this rare clinical setting.     

Glioblastoma multiforme with tuberous sclerosis. Report of a case

Gliomas of the CNS associated with tuberous sclerosis have been well documented; malignant degeneration to glioblastoma multiforme, however, is rare. We studied a 17-year-old boy with stigmata of tuberous sclerosis and a cerebral glioblastoma multiforme. The rarity of this occurrence suggests that neoplasms arising from hamartomas may behave differently than those CNS tumors that arise apparently de novo.     

Reduced penetrance in tuberous sclerosis.

Two first cousins are reported with clinical evidence of tuberous sclerosis. The intervening brother and sister show no evidence of the disease on clinical and Wood's lamp examination, nor on CT scan.     

Variability of expression in tuberous sclerosis.

We present three families in whom a diagnosis of tuberous sclerosis is difficult to secure and we review published reports about similar cases. Tuberous sclerosis has been reported to affect as many as 1 in 9400 subjects in the population. The manifestations of this disease vary not only between but also within families. Currently no reliable method of prenatal diagnosis is available. For these reasons, subjects known to be at 50% risk should be assessed scrupulously to clarify their status. These cases illustrate the difficulties in the clinical diagnosis of tuberous sclerosis and further reinforce the need for a molecular method of determining whether an at risk subject has the disease.     

Hamartomatous gastric polyposis in a patient with tuberous sclerosis

A 42-year-old female diagnosed with tuberous sclerosis was found to have multiple polyps in the fundus of stomach. On histologic examination, the lesions were hamartomatous polyps. In tuberous sclerosis, many lesions occur in multiple organs and there are several reports about the frequent association of hamartomatous polyps of the colon. However, gastric manifestation of tuberous sclerosis has not been established probably due to its asymptomatic nature. This is the first report of multiple gastric hamartomatous polyposis in patient with tuberous sclerosis.     

CD44 expression in tuberous sclerosis.

CD44, a cell adhesion molecule, mediates cell-cell and cell-matrix interactions. In the central nervous system, CD44 is expressed in astrocytic processes, predominantly in white matter and subpial regions, suggesting its involvement in the maintenance of a stable central nervous system cytoarchitecture. In this study, we investigated immunohistochemically the expression of CD44 and glial fibrillary acidic protein in neurosurgically resected specimens of patients with or without tuberous sclerosis. In controls, CD44 immunoreactivity was noted in the processes of astrocytes close to blood vessels and subpial cortex. Glial fibrillary acidic protein immunoreactivity was noted in both cell bodies and cytoplasmic processes of astrocytes in white matter. In tubers, CD44 antigen was also noted in the processes of astrocytes close to blood vessels and pial surface, and in abundance in the network of astrocyte processes. Moreover, CD44 antigen showed immunoreactive halos around balloon cells in tubers and around tumor cells in subependymal lesions. Glial fibrillary acidic protein antigen was noted in both cell bodies and cytoplasmic processes of some balloon cells in tubers, but not in tumor cells. In Western blot analyses, the CD44 immunoreactive band was more intense in tubers or subependymal giant-cell tumors than in control tissue. This increase in CD44 antigen seemed to correlate with the degree of astrogliosis. Immunoreactivity surrounding the cell surfaces of balloon or tumor cells suggests that the clustering of these cells may be due to the expression of CD44. Glial fibrillary acidic protein immunoreactive band was detected in tubers, but not in subependymal giant cell tumors.