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Benign lipoblastomatosis: a cervical tumor of children
International
Journal
o ElsevierlNorth-Holland
of Pediatric
Otorhinolaryngology,
Biomedical
Benign lipoblastomatosis:
3 (1981)
163-169
163
Press
a cervical tumor of children
B.S. SOLEM,
T.J. EIDE, H.H. ELVERLAND
Departments
of Otorhinolaryngology
and I.W.S. MAIR
and Pathology,
liniuersity
of Tromsd,
9000
Tromsd
(Norway)
(Received (Accepted
October 16th, 1980) November 24th, 1980)
--__
_--___-__I__
SUMMARY
Two cases are presented of a rarely reported cause of a supraclavicular mass in the neck of young children. Benign lipoblastomatosis has usually been confused clinically with cystic hygroma. The literature is reviewed and the histological differential diagnosis discussed.
The probability of a persistent cervical swelling being malignant in the adult is a cardinal precept in head and neck surgery [7,10]. In the posterior triangle of the neck, particularly inferiorly in the supraclavicular region, this likelihood is even higher, both in adults [ 61 and in children [ 81. I-Iowever, in very young children, developmental anomalies are an important cause of neck tumors, the cystic hygroma being the most frequently encountered, and also having a preferential location in the supraclavicular fossa [ 131. Two cases will be presented which were considered preoperatively to be cystic hygromas, but in which the supraclavicular mass proved to be due to benign lipoblastomatosis.
Case Reports Case 1. A 7-month-old white male was admitted to the Department of Otorhinolaryngology in 1973 with a 4 week history of a swelling on the left side of the neck and of the left upper arm. The previous medical and family history were unremarkable, and the patient was afebrile and without systemic symptoms. On examination, a comparatively well-defined swelling approximately 5 cm in diameter occupied the left supraclavicular region. The mass was soft and appeared cystic on palpation, while the skin and subcutaneous tissues were unremarkable. There was a slight, diffuse increase in the circumference of the left upper arm, while the peripheral pulsation and blood pressure were symmetrical in the upper extremities. Auscultation of the neck swelling was
164
noncontributory, as were routine hematological tests and chest X-rays. The preoperative diagnosis was considered to be either a cystic hygroma or a hemangioma. On the recommendation of the radiologist, contrast medium was injected into the neck tumor without revealing communication with the vascular or lymphatic systems. A low collar incision was made, and the tumor found to consist of numerous spherical masses which appeared macroscopically to be white fatty tissue. These surrounded the jugular sheath and the brachial plexus (Fig. l), and continued inferiorly behind the clavicle, both proximally into the upper mediastinum, and distally along the subclavian vessels into the axilla. External pressure on the floor of the axilla resulted in more of the globular masses appearing in the root of the neck, thus facilitating removal. The inferior extensions of the tumor mass were, however, numerous, and it was considered unlikely that all tissue was included in the operation specimen. Since the frozen section was reported as fatty tissue without evidence of malignancy, it was decided to accept incomplete removal while maintaining anatomical integrity of the contiguous vascular and neural structures. The postoperative course was unremarkable, and the swelling of the upper arm subsided. Two years later the patient was admitted to the general surgery
Fig. 1. View of the operative findings in Case 1 showing the spherical masses of fatty tissue, of which a portion has been removed in order to demonstrate the roots of the brachial plexus. J, internal jugular vein; C, clavicle.
165
department where macroscopically similar tumor masses were removed from the left axilla. No recurrence has been observed since the latter operation. Case 2. A 15-month-old white male was admitted to the department in 19’79 for treatment of a right-sided supraclavicular tumor which had been first observed 3 weeks previously. The mass was again approximately 5 cm in diameter and appeared cystic. Physical and all laboratory examinations were negative, and the lesion was again assumed to be a cystic hygroma. At operation a mass was found deep to the anterior border of the trapezius muscle and superficial to the brachial plexus. The appearance was again that of white adipose tissue, well delimited from surrounding structures, and with no extensions below the clavicle. The mass was removed intact, and the subsequent course has been uneventful. Pathological examination Case 1. The specimen measured 10 X 7 X 4 cm with a smooth nodular surface. On transection, the cut surface had an homogeneous lobular appearance, with interspersed septa of white fibrous tissue. Microscopically the individual lobes showed adipose tissue of varying degrees of differentiation, with mature lipocytes interspersed with various types of lipoblasts; some of
Fig. 2. Representative area from the first surgical specimen of Case 1 showing mature lipocytes intermingled with lipoblasts of varying size. Hematoxylin and eosin. Marker = 50 pm.
Fig. 3. Section from the first surgical specimen of Case 1 again showing mature lipocytes with, in addition, groups of darkly staining cells containing granular cytoplasm and centrally located, round or oval nuclei. Hematoxylin and eosin. Marker = 50 I_tm.
the latter were multivacuolar, round or polyhedral, with mostly eccentrically, but also some centrally, located nuclei (Fig. 2). In some areas lipoblasts with dense eosinophilic cytoplasm and centrally located nuclei resembling hibemoma cells were found (Fig. 3). Spindle shaped lipoblasts were scanty, and neither mitoses, chondroid metaplasia nor extramedullary erythropoiesis were seen. The recurrent tumor had a similar macroscopic appearance, whilst microscopically more mature adipose tissue was found consisting largely of mature lipocytes with only a few, small areas of multivacuolated lipoblasts. Case 2. This tumor was also lobulated, and consisted of well vascularized adipose tissue with mature lipocytes and univacuolar lipoblasts. The nuclei of the latter were eccentrically located, lightly staining, and either stellate or spindle shaped. Some areas of myxoid stroma were present but no mitoses were observed. Discussion The term lipoblastomatosis was introduced by Vellios et al. [12] for a subcutaneous, lobulated tumor removed from the upper trunk and axilla of an &month-old child, which histologically resembled fetal adipose tissue.
167
These authors also performed a study of fatty tissue in a series of human fetuses, and reported that delayed maturation of fat cells could be found up to the time of birth in the axillary, mediastinal and retroperitoneal regions. A similar tumor had been reported earlier [ 111, but was designated as an embryonic lipoma; this case is of interest since the mass appeared first in the axilla in a 5-month-old female child, with subsequent recurrences in the posterior triangle of the neck necessitating four reoperations. Kauffman and Stout [4] reviewed four cases of lipoblastomatosis, of which one was located in the neck, and noted that none of the patients was older than 7 months at the time of onset. A review of the records at the Armed Forces Institute of Pathology produced a series of 35 cases of benign lipoblastomatosis, 88% of which occurred in children younger than three years of age at the time of surgery [ 11; four of these tumors were located in the neck, and in all cases the preoperative diagnosis was cystic hygroma. There was a male predominance of 1.5 : 1, and a recurrence rate of 14% following primary surgery. These authors also described two different types of lipoblastomatosis; a diffuse, with infiltrative growth and a high tendency to recurrence, and a more superficial, encapsulated type, which was more commonly encountered (23 of the 35 cases) and was more amenable to surgical treatment [ 11. The two cases reported here would appear to be representative of this lesion as encountered by the head and neck surgeon. Both patients were young males, the cervical swelling apparently increased quite rapidly in size, was situated in the supraclavicular region, and the clinical picture was considered consistent with the diagnosis of a cystic hygroma. Case 1 is typical of the diffuse form of lipoblastomatosis, with subsequent recurrence due to incomplete removal, while the tumor in Case 2 was of the encapsulated variety. The microscopic findings are also characteristic, showing a lobular architecture with interspersed, vascular connective tissue; the lobules consist of fat cells showing considerable pleomorphism, with mature lipocytes and various types of lipoblasts, but without atypical mitoses [l-3,11,121. An interesting feature is the considerable degree of cellular maturation in the second specimen removed from Case 1, this development being similar to the findings reported by Van Meurs [ll] from successive operation specimens removed from a patient with four recurrences. The histogenesis of benign lipoblastomatosis is still uncertain [ 1,3], although it would appear to be primarily a developmental anomaly, and has been characterized as an adipose hamartoma [1,9,14]. Greco et al. [3] have recently postulated that benign lipoblastomatosis arises from fetal white fat. However, the first surgical specimen removed from Case 1 contained groups of cells which light microscopically resembled brown fat. This may indicate that benign lipoblastomatosis originates from mesenchymal cells or prelipoblasts [ 11, which have the ability to differentiate into both white and brown fat. Histologically, benign lipoblastomatosis must be distinguished from other tumorous conditions of adipose tissue, in particular the hibernoma and liposarcoma.
168
In a review of the world literature in 1976, only 40 cases of hibernoma could be traced [5]. This rare tumor is derived from vestigial remnants of brown fat, which is histologically similar to the tissue of the hibernating gland of lower animals. Only five cases have had a cervical location and, interestingly, four of these were also situated in the supraclavicular region; the hibernoma is, however, firm to palpation, in contrast to the cystic character of benign lipoblastomatosis, and the cells have a granular, eosinophilic cytoplasm with numerous vacuoles and a centrally located nucleus [ 51. The tissue is also more vascular, and ultrastructural studies have shown a considerably greater number and complexity of mitochondria than is found in the lipoblasts of lipoblastomatosis [ 31. Morphological differentiation between liposarcoma and lipoblastomatosis can be problematical, and is reported to be more reliable at the light microscopical level [3]. Liposarcoma is exceptionally rare in the first quinquenniurn of life [ 1,2], lipoblasts with atypical or hyperchromatic nuclei do not occur in benign lipoblastomatosis, and mitotic figures are only very exceptionally found [ 11. Benign lipoblastomatosis is a condition of embryonal fatty tissue, and may give rise to a cervical swelling in the supraclavicular region of young children, which is clinically consistent with a diagnosis of cystic hygroma. Although there are no other reports in the otorhinolaryngological literature, we suspect that the condition is probably more common than the literature would indicate [ 21. Treatment is surgical, but vital structures must be preserved, even at the expense of a possible second operation at a later date. REFERENCES 1 Chung, E.B. and Enzinger, F.M., Benign lipoblastomatosis. An analysis of 35 cases, Cancer, 32 (1973) 482-492. 2 Gibbs, M.K., Soule, E.H., Hayles, A.B. and Telander, R.L., Lipoblastomatosis: a tumor of children, Pediatrics, 60 (1977) 235-238. 3 Greco, M.A., Garcia, R.L. and Vuletin, J.C., Benign lipoblastomatosis, Cancer, 45 (1980) 511-515. 4 Kauffman, S.L. and Stout, A.P., Lipoblastic tumors of children, Cancer, 12 (1959) 912-925. 5 Lawson, W. and Biller, H.F., Cervical hibemoma, Laryngoscope (St. Louis), 86 (1976) 1258-1267. 6 Lundmark, G.J. and Acquarelli, M.J., Unusual supraclavicular masses, Arch. Otolaryng., 91 (1970) 529-533. 7 Martin, H. and Romieu, C., The diagnostic significance of a “lump in the neck”, Postgrad. Med., 11 (1952) 491-500. 8 Moussatos, G.H. and Baffes, T.G., Cervical masses in infants and children, Pediatrics, 32 (1963) 251-256. 9 Shear, M., Lipoblastomatosis of the cheek, Brit. J. Oral Surg., 5 (1967) 173-179. 10 Slaughter, D.P., Majarakis, J.D. and Southwick, H.W., Clinical evaluation of a swelling in the neck, Surg. Clin. N. Amer., 36 (1956) 3-9. 11 Van Meurs, D.P., The transformation of an embryonic lipoma to a common lipoma, Brit. J. Surg., 34 (1943) 282-284.
169 12 Vellios, F., Baez, J. and Shumacker, H.B., Lipoblastomatosis: a tumor of fetal fat different from hibernoma, Amer. J. Pathol., 34 (1958) 1149-1159. 13 Ward, P.H., Harris, P.F. and Downey W., Surgical approach to cystic hygroma of the neck, Arch. Otolaryng., 91 (1970) 508-514. 14 Willis, R.A., The Pathology of the Tumours of Children, Oliver and Boyd, Edinburgh, 1962.
Journal
o ElsevierlNorth-Holland
of Pediatric
Otorhinolaryngology,
Biomedical
Benign lipoblastomatosis:
3 (1981)
163-169
163
Press
a cervical tumor of children
B.S. SOLEM,
T.J. EIDE, H.H. ELVERLAND
Departments
of Otorhinolaryngology
and I.W.S. MAIR
and Pathology,
liniuersity
of Tromsd,
9000
Tromsd
(Norway)
(Received (Accepted
October 16th, 1980) November 24th, 1980)
--__
_--___-__I__
SUMMARY
Two cases are presented of a rarely reported cause of a supraclavicular mass in the neck of young children. Benign lipoblastomatosis has usually been confused clinically with cystic hygroma. The literature is reviewed and the histological differential diagnosis discussed.
The probability of a persistent cervical swelling being malignant in the adult is a cardinal precept in head and neck surgery [7,10]. In the posterior triangle of the neck, particularly inferiorly in the supraclavicular region, this likelihood is even higher, both in adults [ 61 and in children [ 81. I-Iowever, in very young children, developmental anomalies are an important cause of neck tumors, the cystic hygroma being the most frequently encountered, and also having a preferential location in the supraclavicular fossa [ 131. Two cases will be presented which were considered preoperatively to be cystic hygromas, but in which the supraclavicular mass proved to be due to benign lipoblastomatosis.
Case Reports Case 1. A 7-month-old white male was admitted to the Department of Otorhinolaryngology in 1973 with a 4 week history of a swelling on the left side of the neck and of the left upper arm. The previous medical and family history were unremarkable, and the patient was afebrile and without systemic symptoms. On examination, a comparatively well-defined swelling approximately 5 cm in diameter occupied the left supraclavicular region. The mass was soft and appeared cystic on palpation, while the skin and subcutaneous tissues were unremarkable. There was a slight, diffuse increase in the circumference of the left upper arm, while the peripheral pulsation and blood pressure were symmetrical in the upper extremities. Auscultation of the neck swelling was
164
noncontributory, as were routine hematological tests and chest X-rays. The preoperative diagnosis was considered to be either a cystic hygroma or a hemangioma. On the recommendation of the radiologist, contrast medium was injected into the neck tumor without revealing communication with the vascular or lymphatic systems. A low collar incision was made, and the tumor found to consist of numerous spherical masses which appeared macroscopically to be white fatty tissue. These surrounded the jugular sheath and the brachial plexus (Fig. l), and continued inferiorly behind the clavicle, both proximally into the upper mediastinum, and distally along the subclavian vessels into the axilla. External pressure on the floor of the axilla resulted in more of the globular masses appearing in the root of the neck, thus facilitating removal. The inferior extensions of the tumor mass were, however, numerous, and it was considered unlikely that all tissue was included in the operation specimen. Since the frozen section was reported as fatty tissue without evidence of malignancy, it was decided to accept incomplete removal while maintaining anatomical integrity of the contiguous vascular and neural structures. The postoperative course was unremarkable, and the swelling of the upper arm subsided. Two years later the patient was admitted to the general surgery
Fig. 1. View of the operative findings in Case 1 showing the spherical masses of fatty tissue, of which a portion has been removed in order to demonstrate the roots of the brachial plexus. J, internal jugular vein; C, clavicle.
165
department where macroscopically similar tumor masses were removed from the left axilla. No recurrence has been observed since the latter operation. Case 2. A 15-month-old white male was admitted to the department in 19’79 for treatment of a right-sided supraclavicular tumor which had been first observed 3 weeks previously. The mass was again approximately 5 cm in diameter and appeared cystic. Physical and all laboratory examinations were negative, and the lesion was again assumed to be a cystic hygroma. At operation a mass was found deep to the anterior border of the trapezius muscle and superficial to the brachial plexus. The appearance was again that of white adipose tissue, well delimited from surrounding structures, and with no extensions below the clavicle. The mass was removed intact, and the subsequent course has been uneventful. Pathological examination Case 1. The specimen measured 10 X 7 X 4 cm with a smooth nodular surface. On transection, the cut surface had an homogeneous lobular appearance, with interspersed septa of white fibrous tissue. Microscopically the individual lobes showed adipose tissue of varying degrees of differentiation, with mature lipocytes interspersed with various types of lipoblasts; some of
Fig. 2. Representative area from the first surgical specimen of Case 1 showing mature lipocytes intermingled with lipoblasts of varying size. Hematoxylin and eosin. Marker = 50 pm.
Fig. 3. Section from the first surgical specimen of Case 1 again showing mature lipocytes with, in addition, groups of darkly staining cells containing granular cytoplasm and centrally located, round or oval nuclei. Hematoxylin and eosin. Marker = 50 I_tm.
the latter were multivacuolar, round or polyhedral, with mostly eccentrically, but also some centrally, located nuclei (Fig. 2). In some areas lipoblasts with dense eosinophilic cytoplasm and centrally located nuclei resembling hibemoma cells were found (Fig. 3). Spindle shaped lipoblasts were scanty, and neither mitoses, chondroid metaplasia nor extramedullary erythropoiesis were seen. The recurrent tumor had a similar macroscopic appearance, whilst microscopically more mature adipose tissue was found consisting largely of mature lipocytes with only a few, small areas of multivacuolated lipoblasts. Case 2. This tumor was also lobulated, and consisted of well vascularized adipose tissue with mature lipocytes and univacuolar lipoblasts. The nuclei of the latter were eccentrically located, lightly staining, and either stellate or spindle shaped. Some areas of myxoid stroma were present but no mitoses were observed. Discussion The term lipoblastomatosis was introduced by Vellios et al. [12] for a subcutaneous, lobulated tumor removed from the upper trunk and axilla of an &month-old child, which histologically resembled fetal adipose tissue.
167
These authors also performed a study of fatty tissue in a series of human fetuses, and reported that delayed maturation of fat cells could be found up to the time of birth in the axillary, mediastinal and retroperitoneal regions. A similar tumor had been reported earlier [ 111, but was designated as an embryonic lipoma; this case is of interest since the mass appeared first in the axilla in a 5-month-old female child, with subsequent recurrences in the posterior triangle of the neck necessitating four reoperations. Kauffman and Stout [4] reviewed four cases of lipoblastomatosis, of which one was located in the neck, and noted that none of the patients was older than 7 months at the time of onset. A review of the records at the Armed Forces Institute of Pathology produced a series of 35 cases of benign lipoblastomatosis, 88% of which occurred in children younger than three years of age at the time of surgery [ 11; four of these tumors were located in the neck, and in all cases the preoperative diagnosis was cystic hygroma. There was a male predominance of 1.5 : 1, and a recurrence rate of 14% following primary surgery. These authors also described two different types of lipoblastomatosis; a diffuse, with infiltrative growth and a high tendency to recurrence, and a more superficial, encapsulated type, which was more commonly encountered (23 of the 35 cases) and was more amenable to surgical treatment [ 11. The two cases reported here would appear to be representative of this lesion as encountered by the head and neck surgeon. Both patients were young males, the cervical swelling apparently increased quite rapidly in size, was situated in the supraclavicular region, and the clinical picture was considered consistent with the diagnosis of a cystic hygroma. Case 1 is typical of the diffuse form of lipoblastomatosis, with subsequent recurrence due to incomplete removal, while the tumor in Case 2 was of the encapsulated variety. The microscopic findings are also characteristic, showing a lobular architecture with interspersed, vascular connective tissue; the lobules consist of fat cells showing considerable pleomorphism, with mature lipocytes and various types of lipoblasts, but without atypical mitoses [l-3,11,121. An interesting feature is the considerable degree of cellular maturation in the second specimen removed from Case 1, this development being similar to the findings reported by Van Meurs [ll] from successive operation specimens removed from a patient with four recurrences. The histogenesis of benign lipoblastomatosis is still uncertain [ 1,3], although it would appear to be primarily a developmental anomaly, and has been characterized as an adipose hamartoma [1,9,14]. Greco et al. [3] have recently postulated that benign lipoblastomatosis arises from fetal white fat. However, the first surgical specimen removed from Case 1 contained groups of cells which light microscopically resembled brown fat. This may indicate that benign lipoblastomatosis originates from mesenchymal cells or prelipoblasts [ 11, which have the ability to differentiate into both white and brown fat. Histologically, benign lipoblastomatosis must be distinguished from other tumorous conditions of adipose tissue, in particular the hibernoma and liposarcoma.
168
In a review of the world literature in 1976, only 40 cases of hibernoma could be traced [5]. This rare tumor is derived from vestigial remnants of brown fat, which is histologically similar to the tissue of the hibernating gland of lower animals. Only five cases have had a cervical location and, interestingly, four of these were also situated in the supraclavicular region; the hibernoma is, however, firm to palpation, in contrast to the cystic character of benign lipoblastomatosis, and the cells have a granular, eosinophilic cytoplasm with numerous vacuoles and a centrally located nucleus [ 51. The tissue is also more vascular, and ultrastructural studies have shown a considerably greater number and complexity of mitochondria than is found in the lipoblasts of lipoblastomatosis [ 31. Morphological differentiation between liposarcoma and lipoblastomatosis can be problematical, and is reported to be more reliable at the light microscopical level [3]. Liposarcoma is exceptionally rare in the first quinquenniurn of life [ 1,2], lipoblasts with atypical or hyperchromatic nuclei do not occur in benign lipoblastomatosis, and mitotic figures are only very exceptionally found [ 11. Benign lipoblastomatosis is a condition of embryonal fatty tissue, and may give rise to a cervical swelling in the supraclavicular region of young children, which is clinically consistent with a diagnosis of cystic hygroma. Although there are no other reports in the otorhinolaryngological literature, we suspect that the condition is probably more common than the literature would indicate [ 21. Treatment is surgical, but vital structures must be preserved, even at the expense of a possible second operation at a later date. REFERENCES 1 Chung, E.B. and Enzinger, F.M., Benign lipoblastomatosis. An analysis of 35 cases, Cancer, 32 (1973) 482-492. 2 Gibbs, M.K., Soule, E.H., Hayles, A.B. and Telander, R.L., Lipoblastomatosis: a tumor of children, Pediatrics, 60 (1977) 235-238. 3 Greco, M.A., Garcia, R.L. and Vuletin, J.C., Benign lipoblastomatosis, Cancer, 45 (1980) 511-515. 4 Kauffman, S.L. and Stout, A.P., Lipoblastic tumors of children, Cancer, 12 (1959) 912-925. 5 Lawson, W. and Biller, H.F., Cervical hibemoma, Laryngoscope (St. Louis), 86 (1976) 1258-1267. 6 Lundmark, G.J. and Acquarelli, M.J., Unusual supraclavicular masses, Arch. Otolaryng., 91 (1970) 529-533. 7 Martin, H. and Romieu, C., The diagnostic significance of a “lump in the neck”, Postgrad. Med., 11 (1952) 491-500. 8 Moussatos, G.H. and Baffes, T.G., Cervical masses in infants and children, Pediatrics, 32 (1963) 251-256. 9 Shear, M., Lipoblastomatosis of the cheek, Brit. J. Oral Surg., 5 (1967) 173-179. 10 Slaughter, D.P., Majarakis, J.D. and Southwick, H.W., Clinical evaluation of a swelling in the neck, Surg. Clin. N. Amer., 36 (1956) 3-9. 11 Van Meurs, D.P., The transformation of an embryonic lipoma to a common lipoma, Brit. J. Surg., 34 (1943) 282-284.
169 12 Vellios, F., Baez, J. and Shumacker, H.B., Lipoblastomatosis: a tumor of fetal fat different from hibernoma, Amer. J. Pathol., 34 (1958) 1149-1159. 13 Ward, P.H., Harris, P.F. and Downey W., Surgical approach to cystic hygroma of the neck, Arch. Otolaryng., 91 (1970) 508-514. 14 Willis, R.A., The Pathology of the Tumours of Children, Oliver and Boyd, Edinburgh, 1962.