Choriocarcinoma

A 42-year-old woman with choriocarcinoma required emergency pulmonary embolectomy under cardiopulmonary bypass. After diagnosis of choriocarcinoma was confirmed by examination of tumor emboli specimens, the patient was treated and had complete remission by chemotherapy over a 6-month period. Although rare, choriocarcinoma should be considered in the differential diagnosis of fertile women presenting with pulmonary embolism.

Key words: cardiopulmonary bypass; choriocarcinoma; emergency; pulmonary artery; pulmonary embolectomy; pulmonary embolism

Abbreviations: hCG = human chorionic gonadotropin; MPA = main pulmonary artery; RPA = right pulmonary artery

**********

Due to their rarity, tumors of the pulmonary arteries are often incorrectly diagnosed as more common diseases, such as pulmonary thromboembolism, and are thus seldom diagnosed during a patient's lifetime. We report a patient with a choriocarcinoma mimicking pulmonary embolism, who required emergency pulmonary embolectomy and had a complete remission with adequate chemotherapy thereafter.

CASE REPORT

A 42-year-old woman presented with exertional dyspnea in August 1999. The patient had three children, the youngest being 4 years old, and she had two previous spontaneous abortions. The chest radiographs showed a bilateral diffuse infiltrative shadow. She was treated for interstitial pneumonia; however, her symptoms became worse. On December 16, pulmonary thromboembolism was suspected and she was urgently admitted to our hospital. On hospital admission, she was orthopneic and could not be placed in a left decubitus position. Arterial blood gas levels under oxygen mask inhalation (5 L/min) were as follows: pH, 7.49; P[O.sub.2], 44 mm Hg; and PC[O.sub.2], 26 mm Hg. The chest enhanced CT showed a filling defect from the main pulmonary artery (MPA) to the right pulmonary artery (RPA) [Fig 1]. On the same day, the patient underwent emergency pulmonary embolectomy under cardiopulmonary bypass, Opening from the MPA to the bilateral pulmonary arteries, a whitish, soft tumor embolus with a papillary surface was found occluding the MPA and extending into the RPA. The tumor embolus was removed as much as possible. Pulmonary arterial pressure dropped from 80 to 50 mm Hg immediately after the operation. However, the patient required ventilator support for subsequent respiratory failure owing to residual tumor emboli.

[FIGURE 1 OMITTED]

Microscopically, the pulmonary tumor emboli specimens showed necrotic tissue in the central area and proliferation of atypical cells in the peripheral areas (Fig 2, top). The cells had hyperchromatic nuclei and eosinophilic cytoplasm with indistinct cell borders forming "syncytiotrophoblastic cells" (Fig 2, bottom). After a diagnosis of choriocarcinoma was made, serum human chorionic gonadotropin (hCG) level was measured and a gynecologic examination was performed. As serum hCG values were > 70,000 mIU/mL, chemotherapy was initiated with actinomycin D, 0.1 mg/[m.sup.2] for 5 days. Then, etoposide, 80 mg/[m.sup.2] on days 1 to 5, and carboplatin at a dose set to the area under the concentration-time curve of 4.0 on day 1 were administered during two courses. After her performance status improved by a level of 2, a high-risk chemotherapy regimen was initiated: etoposide, 100 mg/[m.sup.2] on days 1 to 5; methotrexate, 100 mg/[m.sup.2] via IV bolus on day 1 and 200 mg/[m.sup.2] via IV infusion over 12 h on day 1; actinomycin D, 500 [micro]g via IV bolus on day 2; cyclophosphamide, 600 mg via IV infusion on day 8; and vincristine, 1.0 mg/[m.sup.2] on day 8. This treatment regimen was continued until three consecutive normal hCG levels were reached. After a 6-month period of chemotherapy, the residual lung tumor decreased in size and lung fields of the chest radiographs became clear. On July 20, 2000, the patient was discharged from our hospital in complete remission.

[FIGURE 2 OMITTED]

COMMENT

Bagshawe and Brooks (1) were the first to suggest that pulmonary embolism and pulmonary hypertension could be due to a choriocarcinoma of the pulmonary arteries. Choriocarcinoma is the most aggressive form of gestational trophoblastic disease. Most cases occur following a complete hydatidiform mole. The natural history of untreated choriocarcinoma is characterized by the development of early hematogenous metastases. (2) Some of the vagaries of this tumor have attracted attention, and failure to find a primary growth in the uterus, even on careful microscopic examination, is not infrequent. To the best of our knowledge, only a few cases of primary choriocarcinoma in a patient's lifetime have been reported. (3-6) However, this is the first patient who underwent emergency pulmonary embolectomy and was treated with subsequent chemotherapy after a confirming pathologic diagnosis. The patient had been monitored for interstitial pneumonia for > 5 months, and pulmonary thromboembolism was finally diagnosed. Diagnosis of choriocarcinoma in the pulmonary artery is very difficult in the early stage. (1) In the present case, a pulmonary tumor thrombus was examined histologically and diagnosed as choriocarcinoma for the first time.

Many medical textbooks omit choriocarcinoma as a cause of pulmonary emboli and pulmonary artery hypertension. However, Seckl and coworkers (4) reported that although rare, choriocarcinoma should be considered in the differential diagnosis of fertile women presenting with pulmonary embolism or pulmonary artery hypertension. Furthermore, Savage et al (6) emphasized the importance of considering choriocarcinoma and measuring serum hCG in the investigation of fertile women presenting with pulmonary emboli or pulmonary artery hypertension. In our case, choriocarcinoma was not diagnosed in an early stage. However, chemotherapy was initiated as soon as the diagnosis was made and the patient responded positively, with serum hCG falling to within normal levels. Unfortunately, because the hospitalization was long, the cost of treatment became expensive. The problem of the limited health-care resources is a further consideration. Our results indicate that although rare, choriocarcinoma should be considered in the differential diagnosis of fertile women presenting with pulmonary embolism, because complete remission can be achieved with appropriate chemotherapy.

REFERENCES

(1) Bagshawe KD, Brooks WDW. Subacute pulmonary hypertension due to chorioepithelioma. Lancet 1959; 28:653-658

(2) Rosai J. Female reproductive system. In: Rosai J, ed. In: Ackerman's surgical pathology. 8th ed. St. Louis, MO: Mosby, 1996; 1319-1554

(3) Graham JP, Rotman HH. Tumor emboli presenting as pulmonary hypertension: a diagnostic dilemma. Chest 1976; 69:229-230

(4) Seckl MJ, Rustin GJS, Newlands ES, et al. Pulmonary embolism, pulmonary hypertension, and choriocarcinoma. Lancet 1991; 338:1313-1315

(5) Trubenbach J, Pereira PL, Huppert PE, et al. Primary choriocarcinoma of the pulmonary artery mimicking pulmonary embolism. Br J Radiol 1997; 70:843-845

(6) Savage P, Roddie M, Seckl MJ. A 28-year-old woman with a pulmonary embolus. Lancet 1998; 352:30

* From the Second Department of Surgery (Dr. Higashi) and the Second Department of Pathology (Drs. Watanabe, Shimokawa, Sakasegawa, Masuda, and Sakata), Kagoshima University Faculty of Medicine, Kagoshima, Japan.

Manuscript received April 3, 2001; revision accepted July 12, 2001.

Correspondence to: Shun-ichi Watanabe, MD, The Second Department of Surgery, Kagoshima University Faculty of Medicine, 8-35-1 Sakuragaoka, Kagoshima, 890-8520 Japan

COPYRIGHT 2002 American College of Chest Physicians
COPYRIGHT 2002 Gale Group