- Email: [email protected]
Adenocarcinoma arising in a foregut cyst of the mediastinum
Adenocarcinoma Arising in a Foregut Cyst of the Mediastinurn Johnny B. Olsen, MD, Ole Clemmensen, MD, and Kurt Andersen, MD Department of Thoracic Surgery and Institute of Pathology, Odense University Hospital, Odense, Denmark
A case of malignant transformation in a mediastinal cyst of the esophageal reduplication type is presented. The cyst had been recognized 39 years previously, but remained asymptomatic until sudden growth occurred. It was resected totally from the esophagus and the patient recovered well. A review of the literature showed that malignancy in mediastinal foregut cysts is extremely rare. (Ann Thorac Surg 1991;51:497-9)
Comment
P
rimary mediastinal tumors comprise a broad spectrum of lesions. Among the mediastinal cystic lesions, a small group of primitive foregut derivatives are found. In this paper, a case of adenocarcinoma arising in an intraesophageal duplication cyst is presented. The literature concerning nondiverticular but true cystic mediastinal tumors has been reviewed, and the strategy to manage these lesions is discussed. A 61-year-old man was admitted for surgical removal of a mediastinal tumor. Forty years previously, the lesion had been recognized as a cyst. It had been asymptomatic and appeared unchanged on control roentgenograms for many years. Due to sudden growth and pain, the patient was referred to us (Fig 1).Through a right thoracotomy, a cyst of approximately 1,500 mL was totally excised. The cyst was in contiguity with the esophageal wall, from which it had to be divided by sharp dissection, but there was no attachment to other structures. Gross appearance of the specimen was that of a wellcircumscribed cyst measuring 5 x 8 x 14 cm with a smooth outer surface and a frayed, necrotic inner lining. It contained a brownish, cloudy, serous liquid. Its wall was solid with a thickness of 1 to 2 cm. Microscopic examination showed a varying luminal epithelial lining-simple cuboidal to a well-differentiated ciliated respiratory type of epithelium (Fig 2A). Focally, the epithelium was of immature intestinal type-cylindrical, nonciliated with a few goblet cells. In other areas, the epithelium appeared dysplastic, and there was focal ulceration. In the surrounding wall, foci of well-differentiated adenocarcinoma were found (Fig 2B). The wall had an intestine-like structure with a submucosal layer and a peripheral double Accepted for publication Aug 24, 1990. Address reprint requests to Dr Andersen, Department of Thoracic Surgery, Odense University Hospital, DK-5000Odense, Denmark.
0 1991 by
layered muscular coat. There were distinct ganglionic plexuses. The carcinoma invaded the outer muscular layer, but was not observed beyond it. No cartilage or bronchial glands were found. The cyst was classified as an esophageal reduplication cyst according to accepted criteria, vide infra, with a well-differentiated adenocarcinoma. The resected lymph nodes were without metastases. The postoperative course was uneventful, and the patient was in good condition at follow-up 2 months later.
The Society of Thoracic Surgeons
Thoracic cysts derived from the primitive gut are categorized as gastroenteric, bronchogenic, and esophageal reduplication cysts. The gastroenteric type is thought to arise in embryonic life from adherence of the endodermal tube to the notochord, and during growth, a traction diverticulum is formed, which later develops into a gastroenteric cyst [l-31. These cysts are often attached to the spine, and a great proportion is associated with vertebral malformations [3]. They are practically never in contiguity with the esophagus [l]. The respiratory system arises in the early embryonic life from a ventral outgrowth of the primitive foregut. Bronchogenic cysts are considered to be supernumerary lung buds [2], and they are often lined with ciliated columnar epithelium and have cartilage in the wall [l]. The esophageal reduplication cysts, too, arise from the primitive foregut, which in the early embryonic life is a solid tube. Later, vacuoles arise and fuse to form the lumen. Esophageal duplication cysts are thought to evolve from isolated vacuoles that fail to fuse with the lumen [l, 21. Distinction between bronchogenic and esophageal duplication cysts may be difficult, and esophageal reduplication cysts often are lined with respiratory as well as esophageal epithelium as in the present case. The presence of a double layer of smooth muscle in the cyst wall without any cartilage classifies the cyst as esophageal [2]. Our case satisfies these criteria. We have found few reports of malignancy in thoracic cysts unequivocally derived from the foregut [4, 51. One was an adenocarcinoma in a pedunculated cyst from a 41-year-old man. The pedicle was attached to the fourth costovertebral angle, and consequently, it was classified as a gastroenteric cyst [4]. Another report is of a squamous cell carcinoma in an esophageal sac-like structure in a 63-year-old man. In spite of communication to the esophageal lumen, a double layer of smooth muscle in 0003-4975/91/$3.50
498
CASE REPORT OLSEN ET AL MALIGNANT MEDIASTINAL CYST
Ann Thorac Surg 1991;51:497-9
B Fig 1 . Preoperative chest roentgenogram in anterior ( A ) and lateral (B)views shows the rounded mass protruding into the right hemithorax.
A
the wall was suggestive of a duplication cyst rather than a diverticulum [5]. Additional cases of malignancy in intrathoracic cysts have been reported, but exact classification of the cysts is unsettled: At autopsy of a 65-year-old man, an intramural cystic tumor was found in the deep submucosa and muscularis propria of the esophagus [6]. It was lined by squamous epithelium of esophageal type focally in continuity with an invasive squamous cell carcinoma. Between the cyst and the luminal normal esophageal squamous epithelium, there were nests of normal squamous and transitional epithelium, indicating an inclusion cyst origin of the process, rather than a developmental cyst. Another case [7] was an adenocarcinoma in a small polyp, protruding from the luminal surface of a cyst in the anterior mediastinum of a 48-year-old woman. The cyst was lined with “enteric epithelium,” but its relation to the esophagus was not described, and the cyst cannot be classified with certainty. In contrast to the rarity of malignancy in these primitive foregut cysts, 42% of all mediastinal tumors are malignant [8]. In addition, the close relation to vital mediastinal structures leaves these cysts potentially dangerous. Operation therefore has been strongly recommended in mediastinal tumors [l]. Despite the extreme rarity of malignancy in mediastinal cysts, the only definite diagnosis is obtained by thoracot-
omy, and resection of mediastinal cysts should always be considered when diagnosed.
References 1. Kinvan WO, Walbaum PR, McCormack JM. Cystic intrathoracic derivatives of the foregut and their complications. Thorax 1973;28:424-8. 2. Salyer DC, Salyer WR, Eggleston JC. Benign developmental cysts of the mediastinum. Arch Pathol Lab Med 1977;lOl: 136-9. 3. Fallon M, Gordon ARG, Lendrum AC. Mediastinal cysts of foregut origin associated with vertebral abnormalities. Br J Surg 1954;41:52&33. 4. Chuang MT, Barba FA, Kanako M, Teirstein AS. Adenocarcinoma arising in an intrathoracic duplication cyst of foregut origin: a case report and review of the literature. Cancer 1981;471887-90. 5. Tapia RH, White VA. Squamous cell carcinoma arising in a duplication cyst of the esophagus. Am J Gastroenterol 1985; 80:325-9. 6. McGregor DH, Mills G, Boudet RA. Intramural squamous cell carcinoma of the esophagus. Cancer 1976;371556-61. 7. Doub HI‘. Mediastinal cysts of embryological origin. J Fac Radio1 1951;2:302-11. 8. Davis RD, Oldham HN, Sabiston DC. Primary cysts and neoplasms of the mediastinum: recent changes in clinical presentation, methods of diagnosis, management, and results. Ann Thorac Surg 1987;44:229-37.
CASE REPORT OLSEN ET AL MALIGNANT MEDIASTINAL CYST
Ann Thorac Surg 1991;51:497-9
A
499
B
Fig 2 . The cyst wall has an intestine-like structure and is composed of smooth muscle fibers in perpendicularly oriented layers (A). The luminal surface is lined by respiratory-like epithelium (inset). In other foci the wall is infiltrated by an adenocarcinoma (B). (Hematoxylin and eosin, A, XlOO (X250, inset) before 8% reduction; B, x l 0 0 ( ~ 2 5inset) , before 8% reduction.)
A case of malignant transformation in a mediastinal cyst of the esophageal reduplication type is presented. The cyst had been recognized 39 years previously, but remained asymptomatic until sudden growth occurred. It was resected totally from the esophagus and the patient recovered well. A review of the literature showed that malignancy in mediastinal foregut cysts is extremely rare. (Ann Thorac Surg 1991;51:497-9)
Comment
P
rimary mediastinal tumors comprise a broad spectrum of lesions. Among the mediastinal cystic lesions, a small group of primitive foregut derivatives are found. In this paper, a case of adenocarcinoma arising in an intraesophageal duplication cyst is presented. The literature concerning nondiverticular but true cystic mediastinal tumors has been reviewed, and the strategy to manage these lesions is discussed. A 61-year-old man was admitted for surgical removal of a mediastinal tumor. Forty years previously, the lesion had been recognized as a cyst. It had been asymptomatic and appeared unchanged on control roentgenograms for many years. Due to sudden growth and pain, the patient was referred to us (Fig 1).Through a right thoracotomy, a cyst of approximately 1,500 mL was totally excised. The cyst was in contiguity with the esophageal wall, from which it had to be divided by sharp dissection, but there was no attachment to other structures. Gross appearance of the specimen was that of a wellcircumscribed cyst measuring 5 x 8 x 14 cm with a smooth outer surface and a frayed, necrotic inner lining. It contained a brownish, cloudy, serous liquid. Its wall was solid with a thickness of 1 to 2 cm. Microscopic examination showed a varying luminal epithelial lining-simple cuboidal to a well-differentiated ciliated respiratory type of epithelium (Fig 2A). Focally, the epithelium was of immature intestinal type-cylindrical, nonciliated with a few goblet cells. In other areas, the epithelium appeared dysplastic, and there was focal ulceration. In the surrounding wall, foci of well-differentiated adenocarcinoma were found (Fig 2B). The wall had an intestine-like structure with a submucosal layer and a peripheral double Accepted for publication Aug 24, 1990. Address reprint requests to Dr Andersen, Department of Thoracic Surgery, Odense University Hospital, DK-5000Odense, Denmark.
0 1991 by
layered muscular coat. There were distinct ganglionic plexuses. The carcinoma invaded the outer muscular layer, but was not observed beyond it. No cartilage or bronchial glands were found. The cyst was classified as an esophageal reduplication cyst according to accepted criteria, vide infra, with a well-differentiated adenocarcinoma. The resected lymph nodes were without metastases. The postoperative course was uneventful, and the patient was in good condition at follow-up 2 months later.
The Society of Thoracic Surgeons
Thoracic cysts derived from the primitive gut are categorized as gastroenteric, bronchogenic, and esophageal reduplication cysts. The gastroenteric type is thought to arise in embryonic life from adherence of the endodermal tube to the notochord, and during growth, a traction diverticulum is formed, which later develops into a gastroenteric cyst [l-31. These cysts are often attached to the spine, and a great proportion is associated with vertebral malformations [3]. They are practically never in contiguity with the esophagus [l]. The respiratory system arises in the early embryonic life from a ventral outgrowth of the primitive foregut. Bronchogenic cysts are considered to be supernumerary lung buds [2], and they are often lined with ciliated columnar epithelium and have cartilage in the wall [l]. The esophageal reduplication cysts, too, arise from the primitive foregut, which in the early embryonic life is a solid tube. Later, vacuoles arise and fuse to form the lumen. Esophageal duplication cysts are thought to evolve from isolated vacuoles that fail to fuse with the lumen [l, 21. Distinction between bronchogenic and esophageal duplication cysts may be difficult, and esophageal reduplication cysts often are lined with respiratory as well as esophageal epithelium as in the present case. The presence of a double layer of smooth muscle in the cyst wall without any cartilage classifies the cyst as esophageal [2]. Our case satisfies these criteria. We have found few reports of malignancy in thoracic cysts unequivocally derived from the foregut [4, 51. One was an adenocarcinoma in a pedunculated cyst from a 41-year-old man. The pedicle was attached to the fourth costovertebral angle, and consequently, it was classified as a gastroenteric cyst [4]. Another report is of a squamous cell carcinoma in an esophageal sac-like structure in a 63-year-old man. In spite of communication to the esophageal lumen, a double layer of smooth muscle in 0003-4975/91/$3.50
498
CASE REPORT OLSEN ET AL MALIGNANT MEDIASTINAL CYST
Ann Thorac Surg 1991;51:497-9
B Fig 1 . Preoperative chest roentgenogram in anterior ( A ) and lateral (B)views shows the rounded mass protruding into the right hemithorax.
A
the wall was suggestive of a duplication cyst rather than a diverticulum [5]. Additional cases of malignancy in intrathoracic cysts have been reported, but exact classification of the cysts is unsettled: At autopsy of a 65-year-old man, an intramural cystic tumor was found in the deep submucosa and muscularis propria of the esophagus [6]. It was lined by squamous epithelium of esophageal type focally in continuity with an invasive squamous cell carcinoma. Between the cyst and the luminal normal esophageal squamous epithelium, there were nests of normal squamous and transitional epithelium, indicating an inclusion cyst origin of the process, rather than a developmental cyst. Another case [7] was an adenocarcinoma in a small polyp, protruding from the luminal surface of a cyst in the anterior mediastinum of a 48-year-old woman. The cyst was lined with “enteric epithelium,” but its relation to the esophagus was not described, and the cyst cannot be classified with certainty. In contrast to the rarity of malignancy in these primitive foregut cysts, 42% of all mediastinal tumors are malignant [8]. In addition, the close relation to vital mediastinal structures leaves these cysts potentially dangerous. Operation therefore has been strongly recommended in mediastinal tumors [l]. Despite the extreme rarity of malignancy in mediastinal cysts, the only definite diagnosis is obtained by thoracot-
omy, and resection of mediastinal cysts should always be considered when diagnosed.
References 1. Kinvan WO, Walbaum PR, McCormack JM. Cystic intrathoracic derivatives of the foregut and their complications. Thorax 1973;28:424-8. 2. Salyer DC, Salyer WR, Eggleston JC. Benign developmental cysts of the mediastinum. Arch Pathol Lab Med 1977;lOl: 136-9. 3. Fallon M, Gordon ARG, Lendrum AC. Mediastinal cysts of foregut origin associated with vertebral abnormalities. Br J Surg 1954;41:52&33. 4. Chuang MT, Barba FA, Kanako M, Teirstein AS. Adenocarcinoma arising in an intrathoracic duplication cyst of foregut origin: a case report and review of the literature. Cancer 1981;471887-90. 5. Tapia RH, White VA. Squamous cell carcinoma arising in a duplication cyst of the esophagus. Am J Gastroenterol 1985; 80:325-9. 6. McGregor DH, Mills G, Boudet RA. Intramural squamous cell carcinoma of the esophagus. Cancer 1976;371556-61. 7. Doub HI‘. Mediastinal cysts of embryological origin. J Fac Radio1 1951;2:302-11. 8. Davis RD, Oldham HN, Sabiston DC. Primary cysts and neoplasms of the mediastinum: recent changes in clinical presentation, methods of diagnosis, management, and results. Ann Thorac Surg 1987;44:229-37.
CASE REPORT OLSEN ET AL MALIGNANT MEDIASTINAL CYST
Ann Thorac Surg 1991;51:497-9
A
499
B
Fig 2 . The cyst wall has an intestine-like structure and is composed of smooth muscle fibers in perpendicularly oriented layers (A). The luminal surface is lined by respiratory-like epithelium (inset). In other foci the wall is infiltrated by an adenocarcinoma (B). (Hematoxylin and eosin, A, XlOO (X250, inset) before 8% reduction; B, x l 0 0 ( ~ 2 5inset) , before 8% reduction.)