Generalized myelolipoma
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《伊朗医学》
Departments of Pediatric Hematology-Onco-logy, Pediatric Surgery, and Pathology, Mofid Children’s Hospital, Tehran, Iran .
Myelolipoma is a benign tumor originating from hematopoietic and adipose tissue. This tumor usually develops in the adrenal gland, but rare presentations of extraadrenal myelolipoma are also reported, which usually arise from the presacral region. Herein, we present a 6-year-old girl with myelolipoma with generalized involvement of her abdomen, pelvis, chest, and retroorbital region.
Keywords: Adrenal;apoptosis;Cushing’s syndrome;extramedullary hematopoiesis;myelolipoma
Introduction
yelolipoma is a rare benign adrenal tumor originating from hematopoietic and adipose tis-sue.1 – 4 Though rare, extraadrenal presentations of the tumor also occur. About half of these have occurred in presacral region and others in mediastinum, liver, stomach, lung, spleen, retro-peritoneum, and mesenterium.1, 4 –6, 7 – 12 The exact pathogenesis of the tumor is not well-unders-tood, but the presence of a disorder in the apoptosis pathway was shown.2
Extraadrenal myelolipoma (EAML) can cause tumoral mass effects on adjacent organs, or it is detected incidentally during routine work-up. Hemorrhage, hematoma formation, or rupture may occur in massive tumoral involvement.13 Extramedullary hematopoietic tumors can cause anemia and marrow erythroid hyperplasia, and are on the top of the differential diagnosis list.14
Myelolipoma has four distinct clinicopathologic patterns:3 – 5 1) adrenal myelolipoma; 2) adrenal myelolipoma with hematoma formation; 3) adrenal myelolipoma with other disorders such as Cushing’s syndrome, congenital adrenal hyperplasia, and ganglioneuroma; and 4) EAML.
Imaging studies of the tumor with ultrasonography, computerized tomography (CT), and magnetic resonance imaging (MRI) are helpful in the diagnosis, but the definite diagnosis is only made by biopsy.15, 16
Treatment is not necessary for asymptomatic and nonhemorrhagic tumors; surgical excision of the tumor is reserved only for diagnostic purposes or development of clinical symptoms. Myelolipoma may spontaneously regress in some cases.
Case Report
The patient was a 6-year-old Iranian girl, the forth child of her family, who was born from unrelated parents with a birth weight of 3 kg. She had congenital aplasia of her left upper extremity. In her past medical history occasional episodes of pneumonia and a nasal septum defect repair in her 4th year of age were significant. The patient developed recurrent abdominal pains with moderate distension, one year before admission to Mofid Children’s Hospital, Tehran at the age of six. Laparotomy was done and tissue sampling was performed. The histopathologic study revealed fibroadipose tissue with hematopoietic elements. Review of that specimen revealed myelolipoma without any malignant transformation. Six months later, she was referred to us because of recurrence of her abdominal distension. Then, she weighed 19 kg, had a height of 109 cm, and a head circumference of 50 cm. On physical examination, she had multiple nontender abdominal masses. Her spleen was palpable 5 cm below the left costal margin. She was admitted to and evaluated in the Department of Pediatric Hematology-Oncology. Laboratory studies revealed a white blood cell count of 9200/μL with 74% polymorphonuclear cells and 26% lymphocytes; hemoglobin of 10 g/dL; red cell count of 4.108 × 106/μL; MCV of 83 fL; MCH of 23 pg; platelet count of 532,000/μL; and a 3% reticulocytes. She had an erythrocyte sedimentation rate of 41 mm after first hour; LDH of 560 U/L; blood urea nitrogen of 10 mg/dL; creatinine of 0.5 mg/dL; plasma glucose of 77 mg/dL; uric acid of 4.4 mg/dL; calcium of 9 mg/dL; and phosphorus of 4.5 mg/dL. She had an AST of 9 U/L; ALT of 8 U/L; total bilirubin of 0.3 mg/dL with 0.1mg/dL of direct bilirubin; prothrombin time of 14 sec with control of 13 sec; and a partial thromboplastin time of 35 sec with control of 43 sec.
Abdominal and pelvic ultrasonography revealed infiltrative hyperechoic lesions in the renal sinuses with indistinct borders and decreased renal cortical thickening due to fatty infiltrations. Multiple hyperechoic mass lesions in the right side of the abdomen, below the margin of the kidney were also notable. The size of the spleen and the echogenecity of the liver and spleen were increased.
Abdominal CT scan showed multiple abdominal and pelvic lesions with displacement of the left kidney. Some similar lesions were visible in the retroperitoneum, liver, and spleen too; but the kidneys were, however, normal. Chest CT and brain CT scans were also normal. Bone survey revealed generalized increased bone density. Bone marrow aspiration and biopsy had normal cellularity with 46XX karyotype.
During follow-up, she developed headache. She was reevaluated with orbital and brain CT scans, which revealed bilateral multiple retroorbital masses. For further evaluation, MRI was performed which revealed masses with intermediate signal intensity on T1- and T2-weighed images in the intracraniall space of both orbits. These lesions caused optic nerve sheath displacement, especially on the left side as well as displacement of extraocular muscles in the left orbit. Optic nerve was normal. These findings were compatible with metastatic lesions to the orbit.
Then, she did not have any new hematologic and biochemical findings. Reevaluations of chest and abdominal CT scan also indicated multiple metastases to the lung and abdominal cavity.
The second operation was carried out because of increasing abdominal pain. Multiple abdominal and iliac lesions with mesenteric involvement were resected and an ileoileal anastomosis was performed. The pathology report was myelolipoma.
After six months, she became well. She did not receive any specific therapy and is currently under our follow-up.
Discussion
Although the signs and symptoms of myelolipoma were first described by Gierke in 1906, the term “myelolipoma” was coined by Oberling in 1929. Myelolipoma most commonly involves adrenal gland, which may cause enzyme defects or adrenal hyperplasia. Reported cases of EAML with involvement of mediastinum, lung, liver, spleen, and stomach are very rare.1, 6 – 9, 17 This tumor does not have any pathognomonic signs or symptoms and thus cannot be diagnosed without histopathologic evaluations; ultrasonography and CT scan of the involved site, done by an expert radiologist, may give some clues to the correct diagnosis.15, 16 Fine-needle aspiration under the guidance of CT scan or ultrasonography, can be used instead of open excisional biopsy.17 Foci of extramedullary hemato-poiesis, which can cause severe anemia, marrow erythroid hyperplasia, peripheral blood changes, and hepatosplenomegaly are one of the differential diagnoses. They often occur in the mediastinum or epidural spaces with diverse blood changes but extramedullary myelolipomas usually develop as a single abdominal mass without any hematologic abnormalities.11
There were several points of special interest in our patient; her problems started during early childhood, which is very infrequent for myelolipomas. Adrenal and EAMLs usually develop after the age of 40 years. Problow in 1995 reported two EAMLs in 76 and 68 years of age.8 The first case was a 76-year-old female with involvement of her retroperitoneal region, and the other was a 68-year-old male with renal sinus involvement. Amin et al in 1999, also reported a case of myelolipoma of renal sinus in a 66-year-old male.17 Another specification of our case was diffuse tumoral involvement of her abdomen, pelvis, chest, and retroorbital area. A case of giant bilateral myelolipoma was also reported in 1995 by Allison et al. 3
In the first pathologic review of our case, the possibility of extramedullary hematopoiesis was considered which, for lack of any clinical and hematologic abnormalities, was ruled out. Histopathologic review of the first biopsy specimen in Iran and Germany, and then the second biopsy confirmed the diagnosis of EAML. The patient is currently doing well despite of massive involvement of the trunk and retroperitoneum. She is under close observation in our Hematology Clinic without use of any specific medications.
References
1 Gao B, Sugimura H, Sugimura S, Hattori Y, Iriyama T, Kano H. Mediastinal myelolipoma. Asian Cardiovasc Thorac Ann. 2002; 10: 189 – 190.
2 Cappello F, Farina F, Di Felice V, Marciano V, Todaro M, Balsano G, et al. Defective apoptosis as potential mechanism in the tumorogenesis of myelolipoma. Eur J Histochem. 1999; 43: 15 – 18.
3 Allison KH, Mann GN, Norwood TH, Rubin BP. An unusual case of multiple giant myelolipomas: clinical and pathogenetic implications. Endocr Pathol. 2003; 14: 93 – 100.
4 Yamura Y. A case of retroperitoneal teratoma difficult to distinguish from myelolipoma. Hinyokika Kiko. 2000; 46: 891 – 894.
5 Merchant SH, Herman CM, Amin MB, Ro JY, Troncoso P. Myelolipoma associated with adrenal ganglioneuroma. Arch Pathol Lab Med. 2002; 126: 736 – 737.
6 Franiel T, Fleischer B, Raab BW, Fuzesi L. Bilateral thoracic extraadrenal myelolipoma. Eur J Cardiol Thorac Surg. 2004; 26: 1220 – 1222.
7 Spanat R, Saleh HA, Khatib G. Fine needle aspiration diagnosis of extraadrenal myelolipoma presenting as a pleural mass. Acta Cytol. 1999; 43: 295 – 298.
8 Problow JA. Extraadrenal myelolipoma: report of two cases. South Med J. 1995; 88: 639 – 643.
9 Koizumi J, Harada H, Yamamoto N, Shiiku C, Ogasa T, Takahshi M, et al. A case of mediastinal myelolipoma. Kyobu Geka. 1999; 52: 869 – 871.
10 Appetecchia M, Chilelli M, Sciarretha F, Anza M. Bilateral symptomatic myelolipoma. Urol Int. 1999; 62: 37 – 39.
11 Fowler MR. Extraadrenal myelolipomas compared with extramedullary tumors, a case of presacral myelolipoma. Am J Surg Pathol. 1982; 6: 363 – 374.
12 Kenney PJ, Wagner BJ, Rao P, Heffess CS. Myelolipoma CT and pathologic features. Radiology. 1998; 208: 87 – 95.
13 Rao P, Kenny PJ, Wagner BJ, Davidson AJ. Imaging and pathologic factors of myelolipoma. Radigraphics. 1997; 17: 1373 – 1385.
14 Brietta LK, Watkins D. Giant extraadrenal myelolipoma. Arch Pathol Lab Med. 1994; 118: 188 – 190.
15 Vecchio R, Cacciola RR, Di Martino M, Cottini E, Polara V, Gangemi P, et al. Presacral myelolipoma. G Chir. 2002; 23: 93 – 96.
16 Amano T, Takemae K, Niikkura S, Kouno M, Amanom M. Retroperitoneal hemorrhage due to spontaneous rupture of adrenal myelolipoma. Int Urol. 1999: 6: 585 – 588.
17 Amin MB, Tickoo SK, Schultz D. Myelolipoma of the renal sinus. An unusual site for rare extraadrenal lesions. Arch Pathol Lab Med. 1999; 123: 631 – 634.(Mohammad-Taghi Arzanian M)
Myelolipoma is a benign tumor originating from hematopoietic and adipose tissue. This tumor usually develops in the adrenal gland, but rare presentations of extraadrenal myelolipoma are also reported, which usually arise from the presacral region. Herein, we present a 6-year-old girl with myelolipoma with generalized involvement of her abdomen, pelvis, chest, and retroorbital region.
Keywords: Adrenal;apoptosis;Cushing’s syndrome;extramedullary hematopoiesis;myelolipoma
Introduction
yelolipoma is a rare benign adrenal tumor originating from hematopoietic and adipose tis-sue.1 – 4 Though rare, extraadrenal presentations of the tumor also occur. About half of these have occurred in presacral region and others in mediastinum, liver, stomach, lung, spleen, retro-peritoneum, and mesenterium.1, 4 –6, 7 – 12 The exact pathogenesis of the tumor is not well-unders-tood, but the presence of a disorder in the apoptosis pathway was shown.2
Extraadrenal myelolipoma (EAML) can cause tumoral mass effects on adjacent organs, or it is detected incidentally during routine work-up. Hemorrhage, hematoma formation, or rupture may occur in massive tumoral involvement.13 Extramedullary hematopoietic tumors can cause anemia and marrow erythroid hyperplasia, and are on the top of the differential diagnosis list.14
Myelolipoma has four distinct clinicopathologic patterns:3 – 5 1) adrenal myelolipoma; 2) adrenal myelolipoma with hematoma formation; 3) adrenal myelolipoma with other disorders such as Cushing’s syndrome, congenital adrenal hyperplasia, and ganglioneuroma; and 4) EAML.
Imaging studies of the tumor with ultrasonography, computerized tomography (CT), and magnetic resonance imaging (MRI) are helpful in the diagnosis, but the definite diagnosis is only made by biopsy.15, 16
Treatment is not necessary for asymptomatic and nonhemorrhagic tumors; surgical excision of the tumor is reserved only for diagnostic purposes or development of clinical symptoms. Myelolipoma may spontaneously regress in some cases.
Case Report
The patient was a 6-year-old Iranian girl, the forth child of her family, who was born from unrelated parents with a birth weight of 3 kg. She had congenital aplasia of her left upper extremity. In her past medical history occasional episodes of pneumonia and a nasal septum defect repair in her 4th year of age were significant. The patient developed recurrent abdominal pains with moderate distension, one year before admission to Mofid Children’s Hospital, Tehran at the age of six. Laparotomy was done and tissue sampling was performed. The histopathologic study revealed fibroadipose tissue with hematopoietic elements. Review of that specimen revealed myelolipoma without any malignant transformation. Six months later, she was referred to us because of recurrence of her abdominal distension. Then, she weighed 19 kg, had a height of 109 cm, and a head circumference of 50 cm. On physical examination, she had multiple nontender abdominal masses. Her spleen was palpable 5 cm below the left costal margin. She was admitted to and evaluated in the Department of Pediatric Hematology-Oncology. Laboratory studies revealed a white blood cell count of 9200/μL with 74% polymorphonuclear cells and 26% lymphocytes; hemoglobin of 10 g/dL; red cell count of 4.108 × 106/μL; MCV of 83 fL; MCH of 23 pg; platelet count of 532,000/μL; and a 3% reticulocytes. She had an erythrocyte sedimentation rate of 41 mm after first hour; LDH of 560 U/L; blood urea nitrogen of 10 mg/dL; creatinine of 0.5 mg/dL; plasma glucose of 77 mg/dL; uric acid of 4.4 mg/dL; calcium of 9 mg/dL; and phosphorus of 4.5 mg/dL. She had an AST of 9 U/L; ALT of 8 U/L; total bilirubin of 0.3 mg/dL with 0.1mg/dL of direct bilirubin; prothrombin time of 14 sec with control of 13 sec; and a partial thromboplastin time of 35 sec with control of 43 sec.
Abdominal and pelvic ultrasonography revealed infiltrative hyperechoic lesions in the renal sinuses with indistinct borders and decreased renal cortical thickening due to fatty infiltrations. Multiple hyperechoic mass lesions in the right side of the abdomen, below the margin of the kidney were also notable. The size of the spleen and the echogenecity of the liver and spleen were increased.
Abdominal CT scan showed multiple abdominal and pelvic lesions with displacement of the left kidney. Some similar lesions were visible in the retroperitoneum, liver, and spleen too; but the kidneys were, however, normal. Chest CT and brain CT scans were also normal. Bone survey revealed generalized increased bone density. Bone marrow aspiration and biopsy had normal cellularity with 46XX karyotype.
During follow-up, she developed headache. She was reevaluated with orbital and brain CT scans, which revealed bilateral multiple retroorbital masses. For further evaluation, MRI was performed which revealed masses with intermediate signal intensity on T1- and T2-weighed images in the intracraniall space of both orbits. These lesions caused optic nerve sheath displacement, especially on the left side as well as displacement of extraocular muscles in the left orbit. Optic nerve was normal. These findings were compatible with metastatic lesions to the orbit.
Then, she did not have any new hematologic and biochemical findings. Reevaluations of chest and abdominal CT scan also indicated multiple metastases to the lung and abdominal cavity.
The second operation was carried out because of increasing abdominal pain. Multiple abdominal and iliac lesions with mesenteric involvement were resected and an ileoileal anastomosis was performed. The pathology report was myelolipoma.
After six months, she became well. She did not receive any specific therapy and is currently under our follow-up.
Discussion
Although the signs and symptoms of myelolipoma were first described by Gierke in 1906, the term “myelolipoma” was coined by Oberling in 1929. Myelolipoma most commonly involves adrenal gland, which may cause enzyme defects or adrenal hyperplasia. Reported cases of EAML with involvement of mediastinum, lung, liver, spleen, and stomach are very rare.1, 6 – 9, 17 This tumor does not have any pathognomonic signs or symptoms and thus cannot be diagnosed without histopathologic evaluations; ultrasonography and CT scan of the involved site, done by an expert radiologist, may give some clues to the correct diagnosis.15, 16 Fine-needle aspiration under the guidance of CT scan or ultrasonography, can be used instead of open excisional biopsy.17 Foci of extramedullary hemato-poiesis, which can cause severe anemia, marrow erythroid hyperplasia, peripheral blood changes, and hepatosplenomegaly are one of the differential diagnoses. They often occur in the mediastinum or epidural spaces with diverse blood changes but extramedullary myelolipomas usually develop as a single abdominal mass without any hematologic abnormalities.11
There were several points of special interest in our patient; her problems started during early childhood, which is very infrequent for myelolipomas. Adrenal and EAMLs usually develop after the age of 40 years. Problow in 1995 reported two EAMLs in 76 and 68 years of age.8 The first case was a 76-year-old female with involvement of her retroperitoneal region, and the other was a 68-year-old male with renal sinus involvement. Amin et al in 1999, also reported a case of myelolipoma of renal sinus in a 66-year-old male.17 Another specification of our case was diffuse tumoral involvement of her abdomen, pelvis, chest, and retroorbital area. A case of giant bilateral myelolipoma was also reported in 1995 by Allison et al. 3
In the first pathologic review of our case, the possibility of extramedullary hematopoiesis was considered which, for lack of any clinical and hematologic abnormalities, was ruled out. Histopathologic review of the first biopsy specimen in Iran and Germany, and then the second biopsy confirmed the diagnosis of EAML. The patient is currently doing well despite of massive involvement of the trunk and retroperitoneum. She is under close observation in our Hematology Clinic without use of any specific medications.
References
1 Gao B, Sugimura H, Sugimura S, Hattori Y, Iriyama T, Kano H. Mediastinal myelolipoma. Asian Cardiovasc Thorac Ann. 2002; 10: 189 – 190.
2 Cappello F, Farina F, Di Felice V, Marciano V, Todaro M, Balsano G, et al. Defective apoptosis as potential mechanism in the tumorogenesis of myelolipoma. Eur J Histochem. 1999; 43: 15 – 18.
3 Allison KH, Mann GN, Norwood TH, Rubin BP. An unusual case of multiple giant myelolipomas: clinical and pathogenetic implications. Endocr Pathol. 2003; 14: 93 – 100.
4 Yamura Y. A case of retroperitoneal teratoma difficult to distinguish from myelolipoma. Hinyokika Kiko. 2000; 46: 891 – 894.
5 Merchant SH, Herman CM, Amin MB, Ro JY, Troncoso P. Myelolipoma associated with adrenal ganglioneuroma. Arch Pathol Lab Med. 2002; 126: 736 – 737.
6 Franiel T, Fleischer B, Raab BW, Fuzesi L. Bilateral thoracic extraadrenal myelolipoma. Eur J Cardiol Thorac Surg. 2004; 26: 1220 – 1222.
7 Spanat R, Saleh HA, Khatib G. Fine needle aspiration diagnosis of extraadrenal myelolipoma presenting as a pleural mass. Acta Cytol. 1999; 43: 295 – 298.
8 Problow JA. Extraadrenal myelolipoma: report of two cases. South Med J. 1995; 88: 639 – 643.
9 Koizumi J, Harada H, Yamamoto N, Shiiku C, Ogasa T, Takahshi M, et al. A case of mediastinal myelolipoma. Kyobu Geka. 1999; 52: 869 – 871.
10 Appetecchia M, Chilelli M, Sciarretha F, Anza M. Bilateral symptomatic myelolipoma. Urol Int. 1999; 62: 37 – 39.
11 Fowler MR. Extraadrenal myelolipomas compared with extramedullary tumors, a case of presacral myelolipoma. Am J Surg Pathol. 1982; 6: 363 – 374.
12 Kenney PJ, Wagner BJ, Rao P, Heffess CS. Myelolipoma CT and pathologic features. Radiology. 1998; 208: 87 – 95.
13 Rao P, Kenny PJ, Wagner BJ, Davidson AJ. Imaging and pathologic factors of myelolipoma. Radigraphics. 1997; 17: 1373 – 1385.
14 Brietta LK, Watkins D. Giant extraadrenal myelolipoma. Arch Pathol Lab Med. 1994; 118: 188 – 190.
15 Vecchio R, Cacciola RR, Di Martino M, Cottini E, Polara V, Gangemi P, et al. Presacral myelolipoma. G Chir. 2002; 23: 93 – 96.
16 Amano T, Takemae K, Niikkura S, Kouno M, Amanom M. Retroperitoneal hemorrhage due to spontaneous rupture of adrenal myelolipoma. Int Urol. 1999: 6: 585 – 588.
17 Amin MB, Tickoo SK, Schultz D. Myelolipoma of the renal sinus. An unusual site for rare extraadrenal lesions. Arch Pathol Lab Med. 1999; 123: 631 – 634.(Mohammad-Taghi Arzanian M)