Intrathoracic teratomas almost always occur in the mediastinum, but occasionally, they may be found in the lung as intrapulmonary teratomas. Intrapulmonary teratomas have histologic findings that are similar to those of teratoma from other sites. Two successive patients with intrapulmonary teratomas presented to us in a variable manner. The clinical and radiologic features and the histopathologic findings are presented, and the relevant literature is discussed.

Intrapulmonary and gastric teratoma : report of two cases.J Korean Med Sci. 1999 Jun;14(3):330-4.

The lung and stomach are very unusual sites for teratoma. The histologic findings of intrapulmonary and gastric teratomas are not different from those arising in usual sites, such as the ovary or testis. However, preoperative diagnosis is sometimes difficult to make partly because of unusual location. We report here two cases of teratoma, one intrapulmonary teratoma and the other gastric. The intrapulmonary teratoma in our study had an endobronchial tumor growth, which rules out mediastinal teratoma. Meanwhile gastric teratomas usually present as a submucosal tumor and most cases are reported in infancy and childhood. Gastric teratoma in this study occurred in a 27-year-old man. To the best of our knowledge, this case of intrapulmonary teratoma is the eighth and the gastric teratoma is the first to be reported in Korea.

Intrapulmonary cystic benign teratoma: a case report and review of the literature.Ann Thorac Cardiovasc Surg. 2004 Oct;10(5):290-2.

We describe a 41-year-old woman with a short history of retrosternal chest pain and non-productive cough due to a benign intrapulmonary teratoma originating from the left upper lobe. The clinical, CT features of this rare tumor are presented and the relevant literature is discussed.

A case of intrapulmonary teratoma presenting with expectoration of white hair and cheese-like material.Nihon Kokyuki Gakkai Zasshi. 2003 Mar;41(3):191-5.

A 41-year-old man presented with expectoration of white hair and cheese-like material. The chest radiograph showed a round shadow adjacent to the right hilum. Bronchofiberscopy revealed strands of white hair and an obstruction consisting of sebaceous material in the right B3b bronchus. Right upper lobectomy was performed. Histological examination confirmed the diagnosis of intrapulmonary mature teratoma. This characteristic clinical presentation and the bronchofiberscopic findings may have been specific for the diagnosis of teratoma in this case.

Primary intrapulmonary teratoma presenting as pyothorax.Indian J Chest Dis Allied Sci. 1999 Jan-Mar;41(1):51-5.

A female patient presented with empyema thoracis and was planned for decortication. Peroperatively a cystic mass was found in the left lower lobe which was resected and diagnosed as a case of teratoma of lung on histopathological examination. This unusual case of primary intrapulmonary teratoma is being reported here.

Two cases of intrapulmonary teratoma.Nippon Kyobu Geka Gakkai Zasshi. 1993 Mar;41(3):498-502.

We encountered two unusual cases of intrapulmonary teratoma, one in a 31-year-old female and the other in a 15-year-old female. The chief complaint of both patients was fever, and in both a consolidation was detected in the left upper lobe using routine radiography. We performed left upper lobectomy for the former patient and segmentectomy of the left lingual segment for the latter. Neither tumor communicated with the mediastinum. Histological examination revealed a pulmonary teratoma containing no thymic tissue in both. Intrapulmonary teratoma has been reported to be extremely rare, and only 27 cases including these two have been reported in the literature.

An intrapulmonary teratoma associated with bronchiectasia containing various kinds of primordium: a case report and review of the literature.Virchows Arch. 2000 Apr;436(4):384-8.

An intrapulmonary teratoma (IPT), multiloculated and bronchiectatic, with two polyps inside a 23-year-old man is reported. The IPT, a very rare benign cystic lesion, was communicating with segmental bronchus and was removed by a segmental resection from the upper lobe of the left lung. The teratoma contained various kinds of primordial derivatives, such as mesoderm, ectoderm, and endoderm. Though 65 cases of IPT have been reported in the literature (1839-1996), in the present case there were over 15 germ derivatives, the largest number reported to date. The tumor contained thymic tissue, apart from mediastinum, which may be significant in relation to the pathogenesis of IPT. Clinical manifestations, age, and gender distributions and the kind of germ cell derivatives are discussed.

Intrapulmonary teratoma: a report of three cases.J Med Assoc Thai. 1998 Dec;81(12):1028-33.

Three cases of intrapulmonary teratoma are described. A specific symptom of trichoptysis occurred in two patients. The other presented with only recurrent hemoptysis. All were treated by lobectomy of the affected lung. Pathologic examination in each specimen showed that the tumor had a cystic portion which was connected to the bronchial system and contained sebaceous material and pieces of hair. The solid portion consisted of tissues representing all three germ cell layers. The pathologic findings correlated well with the clinical symptoms and radiologic findings in the patients.

Intrapulmonary teratoma: a case report and review of the literature.J Thorac Imaging. 1992 Jun;7(3):70-7.

Intrapulmonary teratomas are rare; only 30 cases have been reported in the world literature. These tumors are thought to originate from the third pharyngeal pouch. They occur equally in men and women and usually are diagnosed in the second to fourth decade of life. They are more often benign than malignant, although malignant lesions may have a favorable postoperative prognosis and benign lesions may exhibit high morbidity and mortality because of their size and location. These tumors present radiographically as lobulated masses that may contain calcification or peripheral collections of air. They most often occur in the upper lobes. The computed tomographic findings of intrapulmonary teratoma are less well known but have been described in two cases. An additional case is presented with a review of the literature and a tabular summary of the characteristics of this unusual entity.

Benign cystic teratoma of the lung.Postgrad Med. 1988 Mar;83(4):85-6, 91.

A young man with recurrent cough and hemoptysis was found at thoracotomy to have benign intrapulmonary cystic teratoma. Although benign cystic teratomas are a common mediastinal neoplasm, they rarely occur within the lung parenchyma. Fewer than 30 cases have been reported in the literature. Occasionally, patients present with bronchiectasis, abscess, or pneumonia in addition to cough and hemoptysis. The patient in this report had little evidence of infection and recovered rapidly following surgical excision of the mass.

A resected case of teratoma of the lung.Nihon Kyobu Shikkan Gakkai Zasshi. 1992 Jul;30(7):1360-4.

Teratoma of the lung in a 32-year-old female is reported. Abnormal shadow on chest X-ray film was noted at the age of 15 years. Her symptoms were subclinical fever, couch, hemosputum and frequent respiratory infections. Chest X-ray film and CT scan revealed a cyst with an intracystic solid mass in the left upper lung. Bronchogram demonstrated communication of the cyst with B5a and B5b bronchi. The left upper lobe was resected. Microscopic examination of the resected specimen revealed a mature teratoma of the lung. Teratoma of the lung is very rare. This case was diagnosed at surgery and was confirmed by microscopic examination.

Primary choriocarcinoma of the lung manifesting as diffuse alveolar hemorrhage.Arch Pathol Lab Med. 2006 Apr;130(4):540-3

An autopsy case of primary pulmonary choriocarcinoma that manifested as diffuse alveolar hemorrhage is reported. A 44-year-old nurse presented with fever, dry cough, hemoptysis, and progressive dyspnea, and died after a downhill course of 2 weeks. Chest radiographs showed diffuse parenchymal shadows throughout the entire lung and a nodular lesion in the right lower lobe. Findings suggestive of acute renal failure were not seen. The autopsy revealed primary pure choriocarcinoma of the right lower lobe and diffuse alveolar hemorrhage throughout the entire lung. Findings of small vessel vasculitis ("pulmonary alveolar capillaritis") were not observed, and extensive neoplastic involvement of the pulmonary vasculature was considered the cause of the diffuse alveolar hemorrhage. Small metastatic foci were found in the liver, adrenal glands, pancreas, and ovaries. This case shows that primary pulmonary neoplasms, on rare occasions, can produce the clinical and pathologic features of diffuse alveolar hemorrhage, probably through elevated pulmonary venous pressure caused by extensive destruction of the vasculature.

Primary pulmonary choriocarcinoma combined with adenocarcinoma. Pathol Int. 2006 Jul;56(7):402-7.

An extremely rare autopsy case of primary pulmonary choriocarcinoma combined with adenocarcinomatous components in a 77-year-old Japanese man is described. The patient died of rapidly progressive respiratory dysfunction without ante-mortem diagnosis. Autopsy revealed necro-hemorrhagic areas of the primary lung tumor with a typical biphasic pattern of choriocarcinoma. Topographical analysis suggested that moderately to poorly differentiated adenocarcinoma components partially surrounded the choriocarcinomatous components. Moreover, dedifferentiated carcinomatous components were scattered next to both adenocarcinomatous and choriocarcinomatous areas, and a few cells of the dedifferentiated carcinomatous components had a similar immunoreaction to conventional adenocarcinomatous or choriocarcinomatous components, such as surfactant apoprotein A, placental alkaline phosphatase or beta-human chorionic gonadotropin. Additionally, epithelial membrane antigen-positive cytotrophoblastic cells were rarely found in choriocarcinomatous areas. The present case suggests that primary lung choriocarcinoma can occur closely related to conventional pulmonary adenocarcinoma, although collision tumor was not completely ruled out.

Primary pulmonary choriocarcinoma--a series of 7 cases.Indian J Pathol Microbiol. 2004 Oct;47(4):494-6.

Primary pulmonary choriocarcinoma is a rare manifestation of extra-genital malignant germ cell tumour. This is a report of seven such cases, seen in autopsy and surgical materials in a span of 20 years. The age range was from 25 to 60 years, affecting six women and one male. These are aggressive tumours requiring prompt therapy. Only one among the seven survived.

Primary choriocarcinoma of the lung.Hum Pathol. 1985 Dec;16(12):1281-4

Choriocarcinoma was found in the lung of a 34-year-old woman. Examination of the patient's entire body, especially the genital tract, failed to disclose foci of choriocarcinoma other than that in the right lung. After surgery, the levels of human chorionic gonadotropin in the blood and the urine fell. It was concluded that the choriocarcinoma of the lung was, in fact, the primary tumor. The genesis of choriocarcinoma was also studied in ten patients who died after delivery or abortion. Autopsy disclosed trophoblasts in the pulmonary arteries in nine of these ten patients. These findings suggest that primary choriocarcinoma in women is due to pulmonary embolism caused by trophoblasts at the time of abortion or delivery.

Primary choriocarcinoma of the lung. Arch Pathol Lab Med. 1987May;111 (5):477-9.

A case of primary choriocarcinoma of the lung in a postmenopausal woman is described and the literature is reviewed. To our knowledge, this is the first report in the English-language literature of pulmonary choriocarcinoma documented by immunoperoxidase staining for human chorionic gonadotropin, and shown to be primary in the lung by a thorough autopsy. Extragonadal, nongestational choriocarcinoma rarely occurs in the lung; less than 15 cases interpreted as primary pulmonary choriocarcinoma have been reported. This tumor exemplifies expression of a fetal gene in a malignancy of somatic cell origin. We propose that primary pulmonary choriocarcinoma arises from epithelial cells which may undergo metaplasia or divergent differentiation. Such differentiation may occur in visceral carcinomas as a focal change, and rarely as the sole pathway of tumor differentiation in extragonadal organs, where it has been termed primary choriocarcinoma or giant cell carcinoma with ectopic human chorionic gonadotropin production.

Primary choriocarcinoma and human chorionic gonadotrophin-producing giant cell carcinoma of the lung: are they independent entities?Histopathology. 2000 Jan;36(1):17-25

AIMS: Human chorionic gonadotrophin (hCG) is a useful marker for chorionic proliferative disorders, such as choriocarcinoma. Although hCG synthesis in lung cancers is frequent, primary pulmonary choriocarcinoma (PCC) is rare. To clarify the differences between primary choriocarcinoma and hCG-producing giant cell carcinoma (GCC) of the lung, we compared the clinicopathological and immunohistochemical findings of these tumours. METHODS AND RESULTS: Three patients, one with PCC and two with hCG-producing GCC, were included in this study. They were all middle-aged men and habitual smokers. The growth of these tumours and the progression of the clinical courses were extremely rapid, and the patients all died within 8 months after the pulmonary tumours were found. Haemorrhagic appearance was a common macroscopic feature of the specimens obtained. Microscopically, both types of tumours mainly consisted of atypical polygonal cells. While PCC contained many syncytial trophoblast-like multinucleated cells that had strong immunoreactivity for anti-hCG, such cells were relatively few in hCG-producing GCC. These histological and immunohistochemical findings reflected the serum test result for hCG, which was higher in the case of PCC. CONCLUSIONS: There are a few differences between PCC and hCG-producing GCC, as described above. Reliable distinction between them seems to be difficult for pathologists and worthless for clinicians.

Primary choriocarcinoma of the lung. Three cases in men.Zentralbl Pathol. 1991;137(1):74-7.

Choriocarcinoma of the lung was recorded from three males, twice by autopsy and once by biopsy. Its histogenetic aspects are discussed in some detail. High levels of human choriogonadotropin (HCG) were recorded from blood serum and urine. The presence of this hormone in the syncytiotrophoblast and that of carcinoembryonic antigen (CEA) in the cytotrophoblast was positively verified by means of immunofluorescence. Granules of HCG were recordable electron microscopically from cytoplasm of the syncytiotrophoblast.