Copyright ©ERS Journals Ltd 2008 Mediastinal angiomyolipomas in a male patient affected by tuberous sclerosis1 Institute of Pathology, University Hospital Heidelberg, and Depts of 2 Radiology, 3 Thoracic Surgery, and 4 Pneumonology and Critical Care Medicine, Thoraxklinik Heidelberg, University of Heidelberg, Heidelberg, Germany. CORRESPONDENCE: P. A. Schnabel, Institute of Pathology, University of Heidelberg, Im Neuenheimer Feld 220/221, D-69120 Heidelberg, Germany. Fax: 49 62213961672. E-mail: philipp.schnabel{at}med.uni-heidelberg.de Keywords: Angiomyolipoma, chylothorax, mediastinum, pleural effusion, tuberous sclerosis complex
Received: February 21, 2007
Classical angiomyolipomas are benign tumours composed of various tissues, including components of fat, abnormal blood vessels and smooth muscle cells. They are often found in association with tuberous sclerosis complex (TSC). The present study reports a male patient affected by TSC with intermittent, massive chylous pleural effusions, who developed recurrent mediastinal angiomyolipomas. The tumours were characterised via histological and immunohistochemical methods. Although angiomyolipomas frequently occur in the kidneys of TSC patients, this case is the first report of mediastinal angiomyolipomas associated with TSC. Besides lymphangioleiomyomatosis, this differential diagnosis has to be taken into account in the case of chylous pleural effusions and mediastinal masses in tuberous sclerosis complex patients. At 5 yrs of age the male patient was diagnosed with tuberous sclerosis complex (TSC; Bourneville's disease, M. Bourneville-Pringle), presenting with multiple characteristic cutaneous angiofibromas (adenoma sebaceum) on his back and legs. The patient was admitted to the hospital 2 yrs later due to a large tumour of the left kidney. A nephrectomy was performed and the histopathological evaluation revealed an angiomyolipoma, a tumour classically associated with TSC 1. Additionally, the following examinations and computed tomography (CT) scans revealed multiple hamartomas in the right kidney, liver, left ventricular endomyocardium of the posterior wall and in the fundi of both eyes (not shown). The consecutive neurological and ophthalmological examinations revealed no further cerebral abnormalities and the patients history was negative for seizure disorders.
During the further course of illness, the patient was continuously admitted to the hospital with symptoms of dyspnoea, chest pain, nausea and vomiting. In addition to extensive fat- and soft tissue-equivalent extensive masses of the retroperitoneum (putative recurrence of the resected renal angiomyolipoma), radiological and subsequent interventional diagnostics revealed massive chylous pleural effusions that were treated by intercostal drainage. The laboratory values for the pleural effusions were as follows with the normal serum values in parentheses: triglycerides >2,700 mg·dL–1 (0–200 mg·dL–1), cholesterol 169 mg·dL–1 (0–200 mg·dL–1), total proteins 6.1 g·dL–1 (6.6–8.7 g·dL–1), lactatedehydrogenase 386 U·L–1 (135–225 U·L–1). Subsequent diagnostics further revealed a mediastinal mass of uncertain origin in the dorsal mediastinum close to the oesophagus. At this point, the patient was 27 yrs old. In order to specify the tumour, the patient was subjected to a biopsy. Histology revealed a classical angiomyolipoma, which was completely surgically resected. The patient's symptoms and chylous pleural effusions were recurrent 5 yrs after the first resection. Therefore, further diagnostics were performed, which demonstrated a new mediastinal mass (fig. 1
Among other clinical symptoms, such as skeletal sclerosis, epilepsy and mental retardation, TSC is characterised by multiple tumour manifestations in various organs, including the typical so-called adenoma sebaceum (angiofibroma) of the skin, giant cell astrocytoma, high-grade glioma, chordoma, glioneuronal hamartoma, angiomyolipoma and cysts of the kidneys, renal cell carcinoma, cardiac rhabdomyoma, retinal glioma and others 1–3. An involvement of the lungs is uncommon (<1–3% of all patients in different series), but when present, pulmonary manifestation dominates the clinical course of the patient, with dyspnoea and fatigue as the cardinal symptoms 2, 4, 5. Besides LAM, symptoms of spontaneous pneumothorax due to honeycombing and the formation of cysts in the lung parenchyma, cor pulmonale and chronic cough or hemoptysis occur frequently 2, but pulmonary symptoms appear later in life compared with cutaneous and neurological manifestations, with an average presentation age of 34 yrs 6. Chylous pleural effusions in TSC patients are uncommon and raise suspicions about LAM, but this disorder is almost exclusively found in female patients of childbearing age 7 and there are < 10 case reports worldwide of LAM occurring in male patients. LAM is the main cause of chylous pleural effusion in TSC patients. In the current case, the finding of massive tumour growth around mediastinal lymph nodes may explain the recurrent chylous effusions.
Descriptions of mediastinal angiomyolipomas are rare and <10 cases have been described in the literature to date 8. None of the reported cases were related to patients affected by TSC and none of the patients suffered from chylous pleural effusions. Additionally, two cases of an intrapulmonary angiomyolipoma in a TSC patient have been reported 9, 10. Moreover, there is a recent description of a 35-yr-old female patient with LAM and a history of a renal angiomyolipoma, who presented with intermittent palpitations and arrhythmias caused by cardiac compression by a posterior mediastinal angiomyolipoma. However, this mediastinal angiomyolipoma was theorised to represent a direct extension from the retroperitoneum 11. In the present case, thoracic and abdominal CT scans could not identify a retroperitoneal tumour extension from the putative recurrence of the renal angiomyolipoma and, additionally, the second or assumed recurrent mediastinal angiomyolipoma was located in the anterior mediastinum (fig. 1 In summary, angiomyolipomas are frequently found in the kidney, but angiomyolipomas in the mediastinum are exceedingly rare with less than a dozen cases reported to date. The present case is the first description of mediastinal angiomyolipomas in association with tuberous sclerosis complex. Of clinical importance is this demonstration that mediastinal angiomyolipomas and not only lymphangioleiomyomatosis have to be considered as a reason for chylous pleural effusions in patients with tuberous sclerosis complex. Furthermore, angiomyolipomas should be included in the differential diagnosis of pulmonary manifestations and tumours arising in the mediastinum in tuberous sclerosis complex patients.
None declared.
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