CASE REPORTS Primary Endobronchial Granular Cell Myoblastoma Raphael C. Lui, MD, F. Neil McKenzie, MD, FRCS(C), Yong-Doo Kim, MD, and Elliot Senderoff, MD Departments of Surgery and Pathology, Maimonides Medical Center, Brooklyn, New York, and Division of Cardiovascular and Thoracic Surgery, The University of Western Ontario, London, Ontario, Canada Granular cell myoblastoma is a common lesion of uncer- tain histogenesis. It commonly affects the tongue, breast, and subcutaneous tissues. However, its occurrence in the tracheobronchial tree is rare. Although generally a be- nign lesion, isolated malignant granular cell myoblas- toma as well as its coexistence with other primary bron- chogenic carcinomas has been documented. In spite of recent anecdotal reports advocating endoscopic removal of this lesion, we believe definitive surgical excision is a more rational choice of treatment. (Ann Thoruc Surg 1989;48:1135) ranular cell myoblastoma (GCM) is a benign tumor of G ubiquitous anatomical distribution. The most fre- quent sites of occurrence are the tongue, breast, and subcutaneous tissues. Other less common sites of occur- rence include the larynx, esophagus, mediastinum, retro- peritoneum, myocardium, and biliary tree. Its occurrence within the tracheobronchial tree as a primary lesion is rarely reported. The presenting symptoms of bronchial GCM such as cough, recurrent pneumonia, pleuritic pain or hemoptysis, and a mass lesion of the lungs on chest roentgenograms are similar to those of primary bron- chogenic tumors, making it difficult at times to differen- tiate between them. A 45-year-old black woman was seen in consultation for productive cough, exertional dyspnea, and right-sided pleuritic pain of 2 months duration. Medical history included cigarette smoking of one pack a day for 30 years. Chest roentgenograms showed a mass lesion of the right upper lobe, which was confirmed by a computed tomo- graphic scan of the thorax. On admission to the hospital, physical examination was entirely unremarkable except for diminished breath sounds over the right upper lung field. Her admission complete blood count, serum electrolyte levels, and arte- rial blood gases on room air were all within normal limits. Several sputum samples had a normal acid-fast bacillus smear and were negative for bacterial and fungal growth. Cytology was negative for malignant cells. A flexible bronchoscopy was performed under general anesthesia before thoracotomy. The trachea and the left tracheobronchial tree were normal. The orifice of the right upper lobe bronchus was distorted by a 1 x 1-cm grayish yellow submucosal lesion. A mediastinoscopy was per- formed after bronchoscopy, revealing no obvious subcar- inal or paratracheal lymphadenopathy. The patient then underwent a right posterolateral thoracotomy. The right Accepted for publication Dec 29, 1988 Address reprint requests to Dr Lui, Division of Cardiovascular and Thoracic Surgery, The University of Western Ontario Hospital, PO Box 5339, Station A, London, Ontario N6A 5A5, Canada. upper lobe appeared grossly abnormal with consolidation and fibrotic changes. A right upper Iobectomy was per- formed. Frozen section of the bronchial stump was free from tumor. Pathology sections of the right upper lobe showed an obstructing lesion of the proximal bronchus with large polygonal cells containing finely granular eo- sinophilic cytoplasm and small dark vesicular nuclei con- sistent with benign granular cell myoblastoma (Fig 1). There was marked bronchiectasis with acute and chronic inflammatory changes of the right upper lobe paren- chyma. All 12 lymph nodes from the right hilar and paratracheal area were free from tumor. The patient recovered well postoperatively and was discharged on postoperative day 7. She returned to work 6 weeks later and continued to do well 12 months after operation. Comment Granular cell myoblastoma was first described by Abri- kossoff [l] in 1926. The first case of primary endobronchial GCM was reported by Kramer [2] in 1939, and by 1978 only 47 cases had been reported [3]. Between 1978 and 1987, 20 more cases were added to the English-language literature, bringing the total to 68 with this report. Granular cell myoblastoma commonly occurs in the third or fourth decade of life, with the youngest reported patient being a 5-year-old child [4]. It seems to have a predilection for the black population, possibly because of the greater reactive potential of mesenchymal tissues in this group. An even distribution of GCM among both sexes has been observed. Cigarette smoking is a frequent but not constant finding in the reported cases. Although polycentric endobronchial GCM was thought to be rare by earlier authors, a recent review of the literature demon- strated a 13.3% incidence of polycentricity either within the same side or bilaterally [5]. The incidence of multiple organ involvement is about 15.9% [6]. The traditional myogenic origin of granular cell tumors as proposed by Abrikossoff [l] was convincingly chal- lenged in 1950 by I'earse [7], who identified cytoplasmic granules that contained protein and high concentrations of cerebrosides and gangliosides, suggesting a neural 0 1989 by The Society of Thoracic Surgeons 0003-4975/89/$3.50
Transcript
CASE REPORTS
Primary Endobronchial Granular Cell Myoblastoma Raphael C. Lui, MD, F. Neil McKenzie, MD, FRCS(C), Yong-Doo Kim, MD, and Elliot Senderoff, MD Departments of Surgery and Pathology, Maimonides Medical Center, Brooklyn, New York, and Division of Cardiovascular and Thoracic Surgery, The University of Western Ontario, London, Ontario, Canada
Granular cell myoblastoma is a common lesion of uncer- tain histogenesis. It commonly affects the tongue, breast, and subcutaneous tissues. However, its occurrence in the tracheobronchial tree is rare. Although generally a be- nign lesion, isolated malignant granular cell myoblas- toma as well as its coexistence with other primary bron-
chogenic carcinomas has been documented. In spite of recent anecdotal reports advocating endoscopic removal of this lesion, we believe definitive surgical excision is a more rational choice of treatment.
(Ann Thoruc Surg 1989;48:1135)
ranular cell myoblastoma (GCM) is a benign tumor of G ubiquitous anatomical distribution. The most fre- quent sites of occurrence are the tongue, breast, and subcutaneous tissues. Other less common sites of occur- rence include the larynx, esophagus, mediastinum, retro- peritoneum, myocardium, and biliary tree. Its occurrence within the tracheobronchial tree as a primary lesion is rarely reported. The presenting symptoms of bronchial GCM such as cough, recurrent pneumonia, pleuritic pain or hemoptysis, and a mass lesion of the lungs on chest roentgenograms are similar to those of primary bron- chogenic tumors, making it difficult at times to differen- tiate between them.
A 45-year-old black woman was seen in consultation for productive cough, exertional dyspnea, and right-sided pleuritic pain of 2 months duration. Medical history included cigarette smoking of one pack a day for 30 years. Chest roentgenograms showed a mass lesion of the right upper lobe, which was confirmed by a computed tomo- graphic scan of the thorax.
On admission to the hospital, physical examination was entirely unremarkable except for diminished breath sounds over the right upper lung field. Her admission complete blood count, serum electrolyte levels, and arte- rial blood gases on room air were all within normal limits. Several sputum samples had a normal acid-fast bacillus smear and were negative for bacterial and fungal growth. Cytology was negative for malignant cells.
A flexible bronchoscopy was performed under general anesthesia before thoracotomy. The trachea and the left tracheobronchial tree were normal. The orifice of the right upper lobe bronchus was distorted by a 1 x 1-cm grayish yellow submucosal lesion. A mediastinoscopy was per- formed after bronchoscopy, revealing no obvious subcar- inal or paratracheal lymphadenopathy. The patient then underwent a right posterolateral thoracotomy. The right
Accepted for publication Dec 29, 1988
Address reprint requests to Dr Lui, Division of Cardiovascular and Thoracic Surgery, The University of Western Ontario Hospital, PO Box 5339, Station A, London, Ontario N6A 5A5, Canada.
upper lobe appeared grossly abnormal with consolidation and fibrotic changes. A right upper Iobectomy was per- formed. Frozen section of the bronchial stump was free from tumor. Pathology sections of the right upper lobe showed an obstructing lesion of the proximal bronchus with large polygonal cells containing finely granular eo- sinophilic cytoplasm and small dark vesicular nuclei con- sistent with benign granular cell myoblastoma (Fig 1). There was marked bronchiectasis with acute and chronic inflammatory changes of the right upper lobe paren- chyma. All 12 lymph nodes from the right hilar and paratracheal area were free from tumor. The patient recovered well postoperatively and was discharged on postoperative day 7. She returned to work 6 weeks later and continued to do well 12 months after operation.
Comment Granular cell myoblastoma was first described by Abri- kossoff [l] in 1926. The first case of primary endobronchial GCM was reported by Kramer [2] in 1939, and by 1978 only 47 cases had been reported [3]. Between 1978 and 1987, 20 more cases were added to the English-language literature, bringing the total to 68 with this report.
Granular cell myoblastoma commonly occurs in the third or fourth decade of life, with the youngest reported patient being a 5-year-old child [4]. It seems to have a predilection for the black population, possibly because of the greater reactive potential of mesenchymal tissues in this group. An even distribution of GCM among both sexes has been observed. Cigarette smoking is a frequent but not constant finding in the reported cases. Although polycentric endobronchial GCM was thought to be rare by earlier authors, a recent review of the literature demon- strated a 13.3% incidence of polycentricity either within the same side or bilaterally [5]. The incidence of multiple organ involvement is about 15.9% [6].
The traditional myogenic origin of granular cell tumors as proposed by Abrikossoff [l] was convincingly chal- lenged in 1950 by I'earse [7], who identified cytoplasmic granules that contained protein and high concentrations of cerebrosides and gangliosides, suggesting a neural
0 1989 by The Society of Thoracic Surgeons 0003-4975/89/$3.50
114 CASE REPORT LUI ET AL ENDOBRONCHIAL GRANULAR CELL MYOBLASTOMA
Ann Thorac Surg 1989;48:113-5
A
B Fig 1. (A) Photomicrograph showing granular cell myoblastoma cells with eosinophilic granular cytoplasm arranged in cords. (Hematoxylin and eosin, x 100 before 51 % reduction.) ( B ) Photomicrograph showing large, polygonal granular cell myoblastoma cells with fine eosinophilic granules and eccentrically placed nuclei. (Hematoxylin and eosin, ~ 4 0 0 before 51% reduction.)
origin. Subsequent ultrastructural and immunohisto- chemical studies of GCM also demonstrated their similar- ities to Schwann cells [8, 91, thus lending more support to their more recent nomenclature, granular cell schwan- noma.
Granular cell myoblastomas of the bronchus are essen- tially benign neoplasms. However, both isolated malig- nant endobronchial GCM [lo] and the coexistence of a benign GCM and a bronchogenic adenocarcinoma [ l l ] or a squamous cell carcinoma [12] have been reported. As tracheobronchial GCM arises in the bronchi, its clinical manifestation is bronchial obstruction, and tissue diagno- sis is made by bronchoscopic biopsy.
The gross appearance of the endobronchial GCM ranges from a several-millimeter ridgelike thickening of the mucosa to a sessile or pedunculated, polypoid lesion up to 6.5 cm in diameter [13]. The cut surface of the lesion is usually yellowish gray in color. Microscopically the typical GCM cell is large (200 to 300 pm in diameter) and polygonal, with strongly eosinophilic cytoplasm contain- ing numerous prominent, deeply eosinophilic granules.
The nucleus is small and eccentrically placed. The nucleoli are not prominent. Pseudoepitheliomatous hyperplasia of the overlying mucosa is quite frequent and occasionally causes some confusion in differentiating between squamous cell carcinoma and GCM. In about one third of the cases the lesion extends through the entire thickness of the bronchial wall into the parabronchial tissue [13]; however, involvement of the lung parenchyma is quite rare. There are no serum markers for GCM and diagnosis by exfoliative cytology is usually not feasible.
The preferred management of bronchial GCM is clearly surgical resection when there is evidence of extensive destruction of the lung parenchyma caused by chronic obstruction. Depending on the location of the lesion and the extent of parenchymal destruction, either lobectomy or, infrequently, pneumonectomy may be required. Oc- casionally computed tomographic scan of the tracheo- bronchial tree is helpful in preoperative decision making between lobectomy with sleeve resection and pneu- monectomy when the main bronchus is involved [14]. Lesions occurring in the trachea can also be successfully managed by resection and reconstruction [15]. The appro- priate management of a small, asymptomatic GCM has not been clearly established. Several recent articles advo- cated endoscopic removal (with or without use of a laser) of these lesions. However, the incidence of recurrence within 2 years after endoscopic removal has been reported to range from 10% to 54% [3, 61. Because of the potential of GCM for rapid growth and bronchial obstruction, the high incidence of parabronchial tissue involvement ren- dering complete endoscopic removal unlikely, and the small but definite potential for malignant transformation, we feel that adequate surgical resection is the treatment of choice. After surgical excision, long disease-free intervals can be expected in 85% of the patients [16, 171. Radiation therapy and chemotherapy have not been proven efftc- tive [13, 181.
References 1.
2.
3.
4.
5.
6.
7.
8.
Abrikossoff A. Uber Myome, ausgehend von der quergestre- iften willkurlichen Muskulatur. Virchows Arch [A] 1926;260: 215-33. Kramer R. Myoblastoma of the bronchus. Ann Otol Rhino1 Laryngol 1939;48:108M. Valenstein SL, Thurer RJ. Granular cell myoblastoma of the bronchus--Case report and literature review. J Thorac Car- diovasc Surg 1978;76:465-8. Sawada K, Fukuma S, Karasawa K, Suchi T. Granular cell myoblastoma of the bronchus in a child: a case report. Jpn J Surg 1981;ll: 11 1-4. Ivatury R, Shah D, Ascer E, Srinivasan K, Heraud J, Roman M. Granular cell tumor of larynx and bronchus. Ann Thorac Surg 1982;33:69-73. Daniel TM, Smith RH, France HF, Sylvest VM. Transbron- choscopic versus surgical resection of tracheobronchial gran- ular cell myoblastoma. J Thorac Cardiovasc Surg 1980;80: 898-903 Pearse AGE. The histogenesis of granular-cell myoblastoma (? granular-cell perineural fibroblastoma). J Pathol Bacteriol 1950;62:35142. Sobel HJ, Marquet E, Avrin E, Schwarz R. Granular cell myoblastoma. Am J Pathol 1971;65:59-71.
Ann Thorac Surg 1989;48:1 l b 5
9. Nakazato Y, Ishizeki J, Takahashi K, Yamaguchi H. Immu- nohistochemical localization of S-100 protein in granular cell myoblastoma. Cancer 1982;49:1624-8.
10. Malette WG, Berardi RS, Neuberger KM, Lam RC, McClellan JT. Seemingly malignant granular cell myoblastoma of the bronchus. J Thorac Cardiovasc Surg 1972;63:99-104.
11. Gabriel JB Jr, Thomas L, Mendoza CB, Chauhan PM. Gran- ular cell tumor of the bronchus coexisting with a bron- chogenic adenocarcinoma: a case report. J Surg Oncol 1983; 24: 103-6.
12. Hurwitz SS, Conlan AA, Gritzman MC, Krut LH. Coexisting granular cell myoblastoma and squamous carcinoma of the bronchus. Thorax 1982;37392-3.
13. Oparah SS, Subramanian VA. Granular cell myoblastoma of
CASE REPORT LUI ET AL 115 ENDOBRONCHIAL GRANULAR CELL MYOBLASTOMA
the bronchus: report of two cases and review of literature. Ann Thorac Surg 1976;22:199-202.
14. Coleman BG, Arger PH, Stephenson LW. CT features of endobronchial granular cell myoblastoma. J Comput Assist Tomogr 1984;8:998-1000.
15. Archer FL, Harrison RW, Moulder PV. Granular cell myo- blastoma of the trachea and canna treated by resection and reconstruction. J Thorac Cardiovasc Surg 1963;45:53942.
16. Symbas PN, Logan WD Jr, Vakil HC. Granular cell myoblas- toma of the bronchus. Ann Thorac Surg 1970;9:136-42.
17. Benson W. Granular cell tumor (myoblastoma) of the tra- cheobronchial tree. J Thorac Cardiovasc Surg 1966;52:17-23.
18. Klima M, Peters J. Malignant granular cell tumor. Arch Pathol Lab Med 1987;111:1070-3.
