An unusual radiographic finding in pulmonary parenchymal endometriosis. A case report

Copyright C Acta Radiologica 2002

Acta Radiologica 43 (2002) 164–166 Printed in Denmark ¡ All rights reserved

AC TA R A D I O L O G I C A ISSN 0284-1851

AN UNUSUAL RADIOGRAPHIC FINDING IN PULMONARY PARENCHYMAL ENDOMETRIOSIS A case report E. K1, Z. K1, E. C ¸ 2, D. Y3, L. T1 and M. G1 1

Department of Respiratory Medicine, Faculty of Medicine, Istanbul University, 2Division of Respiratory Medicine, Yedikule Chest Diseases Hospital and 3Department of Pathology, Faculty of Medicine, Istanbul University, Istanbul, Turkey.

Abstract

Thoracic endometriosis is an uncommon disorder. In most cases, the diagnosis is based on history alone and radiographic findings depend on the menstrual cycle. CT findings include ill-defined or well-defined opacities, nodular lesions, cavities, cystic changes and bullous formation. We report a case of pulmonary parenchymal endometriosis with an unusual radiographic finding.

Key words: Lungs, endometriosis; CT. Correspondence: Esen Kiyan, Istanbul Universitesi, Istanbul Tip Fakültesi, Gögüs Hastaliklari AD, TR-34390 Capa, Istanbul, Turkey. FAX π90 212 635 27 08. Accepted for publication 3 December 2001.

Endometriosis is an extrauterine growth of endometrial tissue and it affects about 5–10% of women of reproductive age (4). Thoracic endometriosis has been classified as either pleural or parenchymal (4). Pleural endometriosis is believed to be caused by regurgitation of endometrial tissue through the fallopian tubes and migration to the pleura through diaphragmatic fenestrations. Most patients with pleural endometriosis also have pelvic endometriosis. In contrast, parenchymal endometriosis usually occurs in women without co-existing pelvic disease and is believed to arise from embolism of endometrial tissue from the uterus to the lungs via the pulmonary arteries. Pleural endometriosis is the more common form, and usually manifests itself as catamenial pneumothorax or hemothorax, the main symptoms being chest pain and dyspnea. However, parenchymal disease is uncommon, and patients 164

usually demonstrate hemoptysis when the lesions involve the bronchial tree. We report a case of pulmonary parenchymal endometriosis with an unexpected radiographic finding. Case Report

A 33-year-old woman (gravida 1, para 2) was admitted with dyspnea. Dyspnea occurred suddenly on the second day of her menses and progressively increased. There was no history of fever, cough, sputum or hemoptysis. The physical examination was normal. Laboratory investigations were normal. In her past history, she had had an artificial abortion (8 years before) and pelvic endometriosis (5 years before). Pelvic endometriosis had been treated effectively with danazol for 6 months and she remained asymptomatic even after discontinuing the treatment.

PULMONARY PARENCHYMAL ENDOMETRIOSIS

Chest radiography, which was obtained on the second day of her menses, revealed bilateral ill-defined opacities (Fig. a). It was assumed that she had parenchymal endometriosis because the dyspnea was synchronized with the menses and she had had pelvic endometriosis in her past history. Chest CT and bronchoscopy supported the diagnosis and excluded other possible causes of dyspnea. CT performed during the menses showed an ill-defined opacity in the right lower lobe and bilateral, multiple, ring-shaped lesions, which contained parenchyma (Figs. b and c). These lesions were presumed to be secondary to menstrual bleeding. Fiberoptic bronchoscopy revealed no endobronchial lesion and no active bleeding. Bronchoalveolar lavage, however, showed hemosiderin laden alveolar macrophages, which were suggestive of alveolar hemorrhage. One week after cessation of the menses, chest radiography was normal and CT revealed regression of the lesions. Discussion

Thoracic endometriosis is an uncommon disorder. Knowledge of this disease has grown slowly because of the rarity of the condition and the ambiguities in diagnosis and treatment. Definitive diagnosis requires histologic verification, but histopathologic confirmation has been obtained in less than one-third of reported cases (2, 4). In most cases, the diagnosis is established on clinical grounds. A presumptive diagnosis frequently can be based on history alone. Respiratory symptoms usually develop within 72 h of the onset of menses and are typically recurrent. Most reported cases of parenchymal endometriosis in the literature demonstrate a history of hemoptysis (5). The diagnostic yield from bron-

choscopic examination in these patients has been low, since most cases of pulmonary endometriosis involve the distal parenchyma rather than the bronchial mucosa, and since the bleeding site may only be evident during the menses (2). On the other hand, serial CT images of the chest during and in the interval between menses indicate the etiology of bleeding, according to recent reports (2, 3). In the present case, the main symptom was dyspnea, which occurred suddenly on the second day of the menses. There was no hemoptysis. This may be due to the involvement of the distal parenchyma. For this reason, bronchoscopy was not diagnostic. CT images of the chest during and after the menses were, however, diagnostic. Chest radiography and CT can visualize lesions with variable size depending on the menstrual cycle. Both pleural and parenchymal lesions are found more often on the right side than the left (2, 5). Parenchymal endometriosis occurs more frequently in the lower lobes, where blood perfusion is greatest. Although chest radiographs often show normal findings, they can also reveal solitary or multiple nodules, cystic defects and opacities displaying cyclical changes in size (4, 5). CT findings in pulmonary endometriosis include ill-defined or well-defined opacities several centimeters in size, nodular lesions, thin-walled cavities, cystic changes, and bullous formation (4, 5, 7). All of these lesions may vary in size during the menstrual cycle and may disappear after the menses (1). Pulmonary nodules were observed more often in older women. With increasing age, hormonal support for the viable endometrial tissue decreases and endometrial tissue with surrounding fibrotic tissue may occur as a lung mass or infiltrate on a chest radiograph (6). In the present case with the diagnosis of paren-

Figure. A 33-year-old woman with parenchymal endometriosis. a) Posteroanterior chest radiograph shows poorly marginated area of consolidation in the right lower lobe. Note also multiple ill-defined opacities in the left lower lobe. b) CT through the mid-lungs shows bilateral multiple-shaped lesions of various sizes. Note parenchyma within the rings. c) CT through the lung bases shows an ill-defined opacity 4¿6 cm in size, which is located in the periphery of the right lower lobe. Note associated ring-shaped lesions in the left lung.

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chymal endometriosis, CT of the chest revealed a large opacity on the right side, which was a known radiological finding of parenchymal endometriosis. It also revealed bilateral multiple ring-shaped lesions. These rings, containing parenchyma, might be caused by parenchymal blood oozing through the interstitial space. To our knowledge, this radiological finding of parenchymal endometriosis has not been reported before.

2. 3. 4. 5. 6.

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