Unsuspected Metastatic Choriocarcinoma Presenting as Unilateral Spontaneous Pneumothorax Denise Ouellette, FRCSC, and Richard Inculet, FRCSC Victoria Hospital, London, Ontario, Canada
Spontaneous pneumothoraces are usually caused by subpleural apical blebs but may also be secondary to metastasis to the lung. We present the case of a 20-year-old woman with spontaneous pneumothorax secondary to choriocarcinoma metastatic to the lung. (Ann Thorac Surg 1992;53:1445)
S
pontaneous pneumothorax in young adults is relatively common. The overall incident is estimated at 5 to 10 per 100,000 per year and as high as 1 in 500 young men. Pneumothorax in this age group is usually the result of the rupture of an apical lung bleb but may also be secondary to underlying pulmonary pathology such as emphysema, tuberculosis, eosinophilic granuloma, and rarely lung neoplasm (primary and secondary). The latter group is quite uncommon. In a review of 1,143 patients with spontaneous pneumothorax, 10 cases were attributed to metastases to lung. Five of these were secondary to metastatic sarcoma [l]. Although choriocarcinoma frequently metastasizes to the lung, in the English-language literature there is only 1 reported case of bilateral spontaneous pneumothorax in a patient with choriocarcinoma, but lung metastases was not proven [2]. We report a case of metastatic choriocarcinoma to the lung presenting as a spontaneous pneumothorax. A 20-year-old woman was seen at a community hospital with sudden shortness of breath and chest pain. She was found to have a left spontaneous pneumothorax. A chest tube was inserted, but an air leak persisted for 3 weeks. Attempted clamping of the chest tube resulted in collapse of the lung. She was referred to our institution. On arrival she was in no distress and her physical examination was essentially normal except for an air leak from her chest tube. The chest tube was soon able to be removed, with the lung reexpanded, and she was discharged. She returned 2 days later with left-sided chest pain and shortness of breath. A chest roentgenogram showed recurrence of her left pneumothorax. A Heimlich valve was inserted with relief of symptoms and complete expansion of her lung. As this was her second pneumothoAccepted for publication June 14, 1991. Address reprint requests to L k Inculet, Division of Thoracic Surgery, Victoria Hospital, 375 South St, London, Ont, N6A 4G5, Canada.
0 1992 by The Society of Thoracic Surgeons
rax in a short period it was decided to proceed with a left transaxillary thoracotomy and exploration. This was performed the following day. A bulla was found at the apex and was excised. Mechanical pleurodesis of the apex of the pleura was then performed. Postoperatively she did well, and after a few days, the chest tube was removed as there was no air leak and minimal drainage. The following day a chest roentgenogram showed a basal pneumothorax. Over the next few days it continued to increase in size, but with the apex well adherent to the chest wall. The decision was then made to perform a formal left thoracotomy to explore for further bullae. At thoracotomy, air could be seen leaking from the fissure. On the undersurface of the left upper lobe a 2-mm yellowish nodule was found from which air could be seen bubbling out. This was excised with a wedge excision. Postoperatively the lung remained well expanded. On the specimen of the lung a 1 x 0.6 x 0.3-cm nodule was visible. Microscopic examination revealed the nodule to be subpleural, containing necrotic cells and a few islands of viable cells. These cells consisted of large, highly atypical cells with abundant cytoplasm and irregular nuclei. They stained positively for cytokeratin and &human chorionic gonadotropin. These features are consistent with a choriocarcinoma. Thus the diagnosis of metastatic choriocarcinoma to the left upper lobe was made. With this information, the patient was further questioned and admitted to being pregnant 5 years earlier and having a therapeutic abortion. At the time of her dilation and curettage she was told that she had a ”grapelike lesion” that may reoccur. The pathologic slides from material obtained were reviewed and showed multiple edematous avascular chorionic villi covered by trophoblast, consistent with hydatidiform mole. Subsequent full metastatic work-up including p h u m a n chorionic gonadotropin analysis and computed tomographic scan of the head, chest, and abdomen has failed to demonstrate other sites of metastases.
Comment The lung is a frequent site for metastasis from malignant neoplasms presenting as a diffuse infiltrate, a single mass, multiple nodules, or pleural effusion. Pneumothorax is an unusual presentation of lung metastasis and was first described by de Barrin in 1937 [3]. Tumors associated with pneumothorax include sarcoma; Ewing’s sarcoma; teratoma; Wilm’s tumor; malignant melanoma; carcinoma of 0003-4975/92/$3.50
Ann Thorac Surg 1992;- 144-5
the cervix, pancreas, or kidney; leiomyosarcoma of the uterus; and, most commonly, osteogenic sarcoma. Two mechanisms have been speculated for pneumothorax secondary to cancer. The first consists of tumor emboli in a subpleural position with infarction of the lung, necrosis, and air leakage [4]. The second mechanism involves tumor growth causing obstruction as a ball-valve effect, resulting in the disruption of the alveoli and leaking of air, which dissects into the subpleural space and forms blebs that rupture [5]. The only other reported case of choriocarcinoma with bilateral pneumothoraces was in a young woman who had a pelvic mass that was found to be a primary nongestational choriocarcinoma of the ovary. She died postoperatively with respiratory failure and hypotension. Unfortunately an autopsy was not performed; thus it is unclear if she had lung metastasis [2]. Hydatidiform mole is considered a benign disorder, but choriocarcinoma develops in 1%of these patients. Choriocarcinoma is a rare, highly malignant tumor and frequently metastasizes hematogenously to the lung, vagina, liver, and brain [6]. Spontaneous pneumothorax is relatively frequent in
CASE REPORT OUELLETTE AND INCULET METASTATIC CHORIOCARCINOMA
145
young patients and is usually primary in nature and due to rupture of an apical subpleural bleb. However, one should keep in mind the possibility of pneumothorax occurring secondary to a lung metastasis.
References 1. Dines DE, et al. Malignant pulmonary neoplasm predisposing to spontaneous pneumothorax. Mayo Clin Proc 1973;48:541-4. 2. Stevens RP, Peirce TH, Dooly PC, Parson GH. Bilateral spontaneous pneumothorax in nongestational choriocarcinoma. CMAJ 1979;12083&1. 3. De Barrin J. Haemopmeunothorax spontane dans une metastase pulmonaire de sarcome osseux. Bull Mem Soc Radio1 Fr 1937;25:73. 4. Thornton TF, Bigelow RR. Pneumothorax due to metastatic sarcoma: report of 2 cases. Arch Pathol 1944;37334. 5. Macklii CC. Transport of air along sheaths of pulmonary blood vessels from alveoli to mediastinum: clinical implication. Arch Intern Med 1939;64:913. 6. Stander RW. Abnormality of the placenta, membranes and fetus. In: Danforth DN. Obstetrics and gynecology. Harper and Row, 3rd ed. 19T7:72&9.
Spontaneous pneumothoraces are usually caused by subpleural apical blebs but may also be secondary to metastasis to the lung. We present the case of a 20-year-old woman with spontaneous pneumothorax secondary to choriocarcinoma metastatic to the lung. (Ann Thorac Surg 1992;53:1445)
S
pontaneous pneumothorax in young adults is relatively common. The overall incident is estimated at 5 to 10 per 100,000 per year and as high as 1 in 500 young men. Pneumothorax in this age group is usually the result of the rupture of an apical lung bleb but may also be secondary to underlying pulmonary pathology such as emphysema, tuberculosis, eosinophilic granuloma, and rarely lung neoplasm (primary and secondary). The latter group is quite uncommon. In a review of 1,143 patients with spontaneous pneumothorax, 10 cases were attributed to metastases to lung. Five of these were secondary to metastatic sarcoma [l]. Although choriocarcinoma frequently metastasizes to the lung, in the English-language literature there is only 1 reported case of bilateral spontaneous pneumothorax in a patient with choriocarcinoma, but lung metastases was not proven [2]. We report a case of metastatic choriocarcinoma to the lung presenting as a spontaneous pneumothorax. A 20-year-old woman was seen at a community hospital with sudden shortness of breath and chest pain. She was found to have a left spontaneous pneumothorax. A chest tube was inserted, but an air leak persisted for 3 weeks. Attempted clamping of the chest tube resulted in collapse of the lung. She was referred to our institution. On arrival she was in no distress and her physical examination was essentially normal except for an air leak from her chest tube. The chest tube was soon able to be removed, with the lung reexpanded, and she was discharged. She returned 2 days later with left-sided chest pain and shortness of breath. A chest roentgenogram showed recurrence of her left pneumothorax. A Heimlich valve was inserted with relief of symptoms and complete expansion of her lung. As this was her second pneumothoAccepted for publication June 14, 1991. Address reprint requests to L k Inculet, Division of Thoracic Surgery, Victoria Hospital, 375 South St, London, Ont, N6A 4G5, Canada.
0 1992 by The Society of Thoracic Surgeons
rax in a short period it was decided to proceed with a left transaxillary thoracotomy and exploration. This was performed the following day. A bulla was found at the apex and was excised. Mechanical pleurodesis of the apex of the pleura was then performed. Postoperatively she did well, and after a few days, the chest tube was removed as there was no air leak and minimal drainage. The following day a chest roentgenogram showed a basal pneumothorax. Over the next few days it continued to increase in size, but with the apex well adherent to the chest wall. The decision was then made to perform a formal left thoracotomy to explore for further bullae. At thoracotomy, air could be seen leaking from the fissure. On the undersurface of the left upper lobe a 2-mm yellowish nodule was found from which air could be seen bubbling out. This was excised with a wedge excision. Postoperatively the lung remained well expanded. On the specimen of the lung a 1 x 0.6 x 0.3-cm nodule was visible. Microscopic examination revealed the nodule to be subpleural, containing necrotic cells and a few islands of viable cells. These cells consisted of large, highly atypical cells with abundant cytoplasm and irregular nuclei. They stained positively for cytokeratin and &human chorionic gonadotropin. These features are consistent with a choriocarcinoma. Thus the diagnosis of metastatic choriocarcinoma to the left upper lobe was made. With this information, the patient was further questioned and admitted to being pregnant 5 years earlier and having a therapeutic abortion. At the time of her dilation and curettage she was told that she had a ”grapelike lesion” that may reoccur. The pathologic slides from material obtained were reviewed and showed multiple edematous avascular chorionic villi covered by trophoblast, consistent with hydatidiform mole. Subsequent full metastatic work-up including p h u m a n chorionic gonadotropin analysis and computed tomographic scan of the head, chest, and abdomen has failed to demonstrate other sites of metastases.
Comment The lung is a frequent site for metastasis from malignant neoplasms presenting as a diffuse infiltrate, a single mass, multiple nodules, or pleural effusion. Pneumothorax is an unusual presentation of lung metastasis and was first described by de Barrin in 1937 [3]. Tumors associated with pneumothorax include sarcoma; Ewing’s sarcoma; teratoma; Wilm’s tumor; malignant melanoma; carcinoma of 0003-4975/92/$3.50
Ann Thorac Surg 1992;- 144-5
the cervix, pancreas, or kidney; leiomyosarcoma of the uterus; and, most commonly, osteogenic sarcoma. Two mechanisms have been speculated for pneumothorax secondary to cancer. The first consists of tumor emboli in a subpleural position with infarction of the lung, necrosis, and air leakage [4]. The second mechanism involves tumor growth causing obstruction as a ball-valve effect, resulting in the disruption of the alveoli and leaking of air, which dissects into the subpleural space and forms blebs that rupture [5]. The only other reported case of choriocarcinoma with bilateral pneumothoraces was in a young woman who had a pelvic mass that was found to be a primary nongestational choriocarcinoma of the ovary. She died postoperatively with respiratory failure and hypotension. Unfortunately an autopsy was not performed; thus it is unclear if she had lung metastasis [2]. Hydatidiform mole is considered a benign disorder, but choriocarcinoma develops in 1%of these patients. Choriocarcinoma is a rare, highly malignant tumor and frequently metastasizes hematogenously to the lung, vagina, liver, and brain [6]. Spontaneous pneumothorax is relatively frequent in
CASE REPORT OUELLETTE AND INCULET METASTATIC CHORIOCARCINOMA
145
young patients and is usually primary in nature and due to rupture of an apical subpleural bleb. However, one should keep in mind the possibility of pneumothorax occurring secondary to a lung metastasis.
References 1. Dines DE, et al. Malignant pulmonary neoplasm predisposing to spontaneous pneumothorax. Mayo Clin Proc 1973;48:541-4. 2. Stevens RP, Peirce TH, Dooly PC, Parson GH. Bilateral spontaneous pneumothorax in nongestational choriocarcinoma. CMAJ 1979;12083&1. 3. De Barrin J. Haemopmeunothorax spontane dans une metastase pulmonaire de sarcome osseux. Bull Mem Soc Radio1 Fr 1937;25:73. 4. Thornton TF, Bigelow RR. Pneumothorax due to metastatic sarcoma: report of 2 cases. Arch Pathol 1944;37334. 5. Macklii CC. Transport of air along sheaths of pulmonary blood vessels from alveoli to mediastinum: clinical implication. Arch Intern Med 1939;64:913. 6. Stander RW. Abnormality of the placenta, membranes and fetus. In: Danforth DN. Obstetrics and gynecology. Harper and Row, 3rd ed. 19T7:72&9.
