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A Rare Case of Double Parathyroid Lipoadenoma With Hyperparathyroidism
CASE REPORT
A Rare Case of Double Parathyroid Lipoadenoma With Hyperparathyroidism Cristina Ogrin, MD
Abstract: A rare case of double lipoadenomas of parathyroid glands with hyperparathyroidism is described. A 56-year-old woman was referred for management of diabetes. Work up revealed: serum Calcium (Ca) 511.9 mg/dl, glomerular filtration rate (GFR) 5 103 ml/min/m2, parathyroid hormone (PTH) 5 60 pg/ml, Phosphorus 5 3.0 mg/dl, 25 hydroxy vitamin D (25 OH D) 516.5 ng/ml, 24 h urine Calcium 5179 mg/day. Parathyroid sestamibi scan showed increased activity in the left thyroid and right thyroid lobe. Single photon emission computed tomography demonstrated uptake in inferior left and right thyroid lobes. Her serum calcium following successful bilateral parathyroidectomy was 9.3 mg/dl. Pathology showed double parathyroid lipoadenomas. After surgery, her serum Calcium and PTH normalized to 9.8 mg/dl and 32 pg/ml respectively. Lipoadenoma has been described as a very rare lesion of the parathyroid gland and is most commonly non-functional. PubMed search failed to reveal any case of hyperparathyroidism due to double parathyroid lipoadenomas. Key Indexing Terms: Hypercalcemia; Parathyroid lipoadenomas; Primary hyperparathyroidism. [Am J Med Sci 2013;346(5):432–434.]
L
ipoadenoma of the parathyroid gland is an unusual cause of primary hyperparathyroidism. Only a few cases are reported in the literature, and the diagnosis was made after parathyroidectomy for primary hyperparathyroidism. Pathology in lipoadenomas usually shows chief cells and prominent stromal adipose tissue. The clinical manifestations and the laboratory findings are indistinguishable from those of the usual forms of primary hyperparathyroidism. A 56-year-old woman of German ethnicity presented for diabetes management. She was not aware of any abnormal high serum calcium in the past, had no family history of parathyroid or calcium disorders and no radiation to the neck. A detailed workup revealed serum calcium (Ca) 5 11.9 mg/dL, ionized Ca 5 6.5 mg/dL, glomerular filtration rate 5 103 mL/min/m2, parathyroid hormone (PTH) 5 60 pg/mL, phosphorus 5 3.0 mg/dL, alkaline phosphatase (ALP) 5 161 IU/L, gamma-glutamyl transferase 5 16 IU/L, bone ALP 5 59.4 mg/l, 25 hydroxyvitamin D 5 16.5 ng/mL, 24-hour urine Ca 5 179 mg/d (Table 1), normal serum and urine protein electrophoresis and normal mammography. Parathyroid sestamibi scan showed increased activity posterior and inferior to the left thyroid lobe and a possible small focus of increased activity superior and inferior to the right thyroid lobe. Single photon emission computed tomography fusion images demonstrated uptake From the From the Department of Endocrine, University of Iowa, Iowa City, Iowa. Submitted February 22, 2013; accepted in revised form May 10, 2013. The author has no financial or other conflicts of interest to disclose. Correspondence: Cristina Ogrin, MD, the Department of Endocrine, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52241 (E-mail: [email protected]).
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within an ovoid soft tissue lesion inferior to the thyroid bed just left of midline and uptake within triangular-shaped soft tissue lesion just inferior to the right thyroid lobe (Figures 1A and 1B). No suspicion of lung cancer was found on contrast chest computed tomography. A right thyroid nodule was found at thyroid ultrasound (Figure 2) and was benign by fine needle aspiration. Bone densitometry revealed osteoporosis of lumbar spine with a T-score of lumbar spine of 22.5, whereas the T-score of total left hip was 21.8. She underwent successful resection of left and right inferior parathyroid glands, and her serum Ca 5 hours after surgery was 9.3 mg/dL. A rapid preoperative PTH from the right internal jugular (IJ) vein was 101 pg/mL. The left inferior parathyroid gland was removed first, and a rapid PTH measured 15 minutes after excision from the left IJ vein was 54 pg/mL. Then the right inferior parathyroid gland was removed, and a rapid PTH level measured 10 minutes after excision was reported as 27 pg/mL (right IJ) and 34 pg/mL (left IJ). Left inferior parathyroid was described as a tanyellow glandular appearing tissue (2.3 3 1.7 3 0.9 cm, weight of 2130 mg), and the right inferior was a pink and tan-yellow well-circumscribed tissue (2.4 3 1.3 3 1.0 cm, weight of 1510 mg). Specimens from the 2 glands removed showed similar histology: hypercellular parathyroid glands composed of a mixture of benign loose connective tissue and adipose tissue, separating cords of chief cells admixed with some oxyphilic cells, characteristic of parathyroid lipoadenomas (Figures 3A and 3B). The proportion of fat was roughly similar between the 2 glands, approximately 40%. Two months after surgery, her serum Ca, PTH and ALP normalized to 9.8 mg/dL, 32 pg/ mL and 108 IU/L, respectively. Parathyroid lipoadenomas are very rare variants of adenomas characterized histologically by an abundance of fat cells and are commonly nonfunctional.1,2 The origin of the fatty tissue component remains unknown, but it has been speculated that the same factors that drive the enlargement of the parathyroid chief cells are responsible for the enlargement of the fatty component. The World Health Organization defines a parathyroid lipoadenoma as a “hamartoma-like benign neoplasm containing both chief cells and prominent stromal elements.” Fat normally occupies approximately 25% of the normal parathyroid gland and may be increased by advanced age and obesity. Chow et al2 were able to identify 5 cases of functioning parathyroid lipoadenomas among 7,120 parathyroidectomies performed for primary hyperparathyroidism over a 30-year period in which fat content was described as .50%. However, the fat content in most published series of parathyroid lipoadenomas is highly variable.1,3,4 In the largest series of 11 cases (8 lipoadenomas and 3 lipohyperplasias), Seethala et al3 reported a median fat content of 50% (range, 30%–70%) in lipoadenomas and 60% (range, 10%–90%) in lipohyperplasia while the mean weights were 1.553 and 389.1 mg for lipoadenomas and lipohyperplasia, respectively. He concluded that accurate weight
The American Journal of the Medical Sciences
Volume 346, Number 5, November 2013
A Rare Case of Double Parathyroid Lipoadenoma With Hyperparathyroidism
TABLE 1. Serum parameters before and after parathyroidectomy Date Ca GFR PTH ALP GGT 9/15/11 9/20/11 12/1/11 1/25/12 4/12/12 4/12/12 6/13/12 Normal range
Bone ALP
25(OH)D
PO4
Ionized Ca
11.1 103 — 168 — — — — — 11.4 108 — 192 — — — — — 11.8 103 42 161 16 — — 3.1 6.6 11.9 103 60 — — 59.4 16.5 3.0 6.5 Patient underwent removal of right and left parathyroid glands 9.3 — — — — — — — — 9.8 128 32 108 — — 32 3.8 — 8.5–10.5 .60 mL/min 15–65 pg/mL 42–121 IU/L 6–65 IU/L 0–21.3 ug/L 30–100 ng/mL 2.7–4.5 mg/dL 4.5–5.6 mg/dL
ALP, alkaline phosphatase; Ca, calcium; GFR, glomerular filtration rate; GGT, gamma-glutamyl transferase; PO4, Phosphorus; PTH, parathyroid hormone; 25(OH)D, 25 hydroxyvitamin D.
FIGURE 1. (A) Fused SPECT/CT (sestamibi) coronal images depict uptake within triangularshaped soft tissue lesion just inferior to the right thyroid lobe (white arrow) and uptake within an ovoid soft tissue lesion just inferior to the thyroid bed just left of midline (white arrowhead). (B) Fused SPECT (sestamibi) axial images depict uptake within triangularshaped soft tissue lesion just inferior to the right thyroid lobe (white arrow) and uptake within an ovoid soft tissue lesion just inferior to the thyroid bed just left of midline (white arrowhead). CT, computed tomography; SPECT, single photon emission computed tomography.
documentation and recognition of key histological features help decrease the challenge of differentiation between lipoadenomas and lipohyperplasia. Clinical manifestations and the laboratory results in patients with functioning lipoadenomas are difficult to differentiate from those of the usual forms of primary hyperparathy-
FIGURE 2. Thyroid ultrasound (sagittal images) shows right thyroid nodule of 1.1 3 0.7 3 0.9 cm with multiple internal calcifications (white arrow). Ó 2013 Lippincott Williams & Wilkins
roidism. The first case of a functional parathyroid lipoadenoma causing hyperparathyroidism was described in 1962,4 and only a few others have been reported since then with the largest series of only 5 patients described by Chow et al.2–13 The unique feature of this case was the presence of 2 functional lipoadenomas located in the inferior right and left parathyroid glands. Lipoadenomas are more difficult to localize preoperatively by imaging due to high fat content. Ultrasound has been reported to identify the tumors in 50% of cases, whereas sestamibi was successful in 71% in a series of 11 cases.3 In our patient, ultrasound did not identify lipoadenomas, whereas sestamibi single photon emission computed tomography images showed increased activity in the left inferior parathyroid gland and a possible small focus of increased activity in the right inferior parathyroid gland. Weight of the right inferior lipoadenoma (1500 mg) was similar to the mean weight previously reported by Seethala et al,3 whereas the weight of the right inferior lipoadenoma was higher (2130 mg). Rapid preoperative PTH measured from right IJ vein was elevated at 101 pg/mL. Rapid PTH measured from both left and right IJ veins after excision of the left and right inferior glands demonstrated a significant decrease in PTH levels to 54 and 34 pg/mL, respectively. In addition to normalization of her serum calcium levels, intraoperative PTH measurement was useful in assessing the adequacy of parathyroidectomy. A significant decrease of the intraoperative PTH confirms that further exploration is not indicated.14
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Ogrin
FIGURE 3. (A) Photomicrograph of parathyroid lipoadenoma shows hypercellular parathyroid glands composed of a mixture of benign loose connective and approximately 40% adipose tissue (black arrowhead) separating cords of chief cells admixed with some oxyphil cells, characteristic of parathyroid lipoadenomas. (Hematoxylin-eosin stain; low power magnification 310.) (B) Photomicrograph of parathyroid lipoadenoma shows hypercellular parathyroid glands composed of a mixture of benign loose connective and approximately 40% adipose tissue separating cords of chief cells (black arrowhead) admixed with some oxyphil cells, characteristic of parathyroid lipoadenomas (Hematoxylin-eosin stain; medium power magnification 340.)
Parathyroid lipoadenomas are rare tumors and uncommonly functional. Here, a unique case of primary hyperparathyroidism due to double parathyroid lipoadenoma is presented. REFERENCES 1. Weiland LH, Garrison RC, ReMine WH. Lipoadenoma of the parathyroid gland. Am J Surg Pathol 1978;2:3–7. 2. Chow LS, Erickson LA, Abu-Lebdeh HS, et al. Parathyroid lipoadenomas: a rare cause of primary hyperparathyroidism. Endocr Pract 2006;12:131–36. 3. Seethala RR, Ogilvie JB, Carty SE, et al. Parathyroid lipoadenomas and lipohyperplasias: clinicopathologic correlations. Am J Surg Pathol 2008;32:1854–67. 4. Abul-Haj SK, Conklin H, Hewitt WC. Functioning lipoadenoma of the parathyroid gland. Report of a unique case. N Engl J Med 1962;266:121–23. 5. Obara T, Fujimoto Y, Ito Y, et al. Functioning parathyroid lipoadenoma—report of four cases: clinicopathological and ultrasonographic features. Endocrinol Jpn 1989;36:135–45. 6. Bansal R, Trivedi P, Sarin J, et al. Lipoadenoma of the parathyroid gland—a rare cause of hyperparathyroidism. Gulf J Oncolog 2012;1:63–5.
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7. Bleiweiss IJ, Harpaz N, Strauchen JA, et al. Functioning lipoadenoma of the parathyroid: case report and literature review. Mt Sinai J Med 1989; 56:114–17. 8. Uden P, Berglund J, Zederfeldt B, et al. Parathyroid lipoadenoma: a rare cause of primary hyperparathyroidism. Case report. Acta Chir Scand 1987;153:635–39. 9. de Leacy EA, Axelsen RA, Kleinman DS, et al. Functioning lipoadenoma of the parathyroid gland. Pathology 1988;20:377–80. 10. Ducatman BS, Wilkerson SY, Brown JA. Functioning parathyroid lipoadenoma. Report of a case diagnosed by intraoperative touch preparations. Arch Pathol Lab Med 1986;110:645–7. 11. Hargreaves HK, Wright TC Jr. A large functioning parathyroid lipoadenoma found in the posterior mediastinum. Am J Clin Pathol 1981; 76:89–93. 12. Wolff M, Goodman EN. Functioning lipoadenoma of a supernumerary parathyroid gland in the mediastinum. Head Neck Surg 1980;2: 302–7. 13. Daroca PJ Jr, Landau RL, Reed RJ, et al. Functioning lipoadenoma of the parathyroid gland. Arch Pathol Lab Med 1977;101:28–9. 14. Lee AY, Wang BY, Heller KS. Importance of intraoperative parathyroid hormone measurement in the diagnosis of parathyroid lipoadenoma. Head Neck 2011;33:917–9.
Volume 346, Number 5, November 2013
A Rare Case of Double Parathyroid Lipoadenoma With Hyperparathyroidism Cristina Ogrin, MD
Abstract: A rare case of double lipoadenomas of parathyroid glands with hyperparathyroidism is described. A 56-year-old woman was referred for management of diabetes. Work up revealed: serum Calcium (Ca) 511.9 mg/dl, glomerular filtration rate (GFR) 5 103 ml/min/m2, parathyroid hormone (PTH) 5 60 pg/ml, Phosphorus 5 3.0 mg/dl, 25 hydroxy vitamin D (25 OH D) 516.5 ng/ml, 24 h urine Calcium 5179 mg/day. Parathyroid sestamibi scan showed increased activity in the left thyroid and right thyroid lobe. Single photon emission computed tomography demonstrated uptake in inferior left and right thyroid lobes. Her serum calcium following successful bilateral parathyroidectomy was 9.3 mg/dl. Pathology showed double parathyroid lipoadenomas. After surgery, her serum Calcium and PTH normalized to 9.8 mg/dl and 32 pg/ml respectively. Lipoadenoma has been described as a very rare lesion of the parathyroid gland and is most commonly non-functional. PubMed search failed to reveal any case of hyperparathyroidism due to double parathyroid lipoadenomas. Key Indexing Terms: Hypercalcemia; Parathyroid lipoadenomas; Primary hyperparathyroidism. [Am J Med Sci 2013;346(5):432–434.]
L
ipoadenoma of the parathyroid gland is an unusual cause of primary hyperparathyroidism. Only a few cases are reported in the literature, and the diagnosis was made after parathyroidectomy for primary hyperparathyroidism. Pathology in lipoadenomas usually shows chief cells and prominent stromal adipose tissue. The clinical manifestations and the laboratory findings are indistinguishable from those of the usual forms of primary hyperparathyroidism. A 56-year-old woman of German ethnicity presented for diabetes management. She was not aware of any abnormal high serum calcium in the past, had no family history of parathyroid or calcium disorders and no radiation to the neck. A detailed workup revealed serum calcium (Ca) 5 11.9 mg/dL, ionized Ca 5 6.5 mg/dL, glomerular filtration rate 5 103 mL/min/m2, parathyroid hormone (PTH) 5 60 pg/mL, phosphorus 5 3.0 mg/dL, alkaline phosphatase (ALP) 5 161 IU/L, gamma-glutamyl transferase 5 16 IU/L, bone ALP 5 59.4 mg/l, 25 hydroxyvitamin D 5 16.5 ng/mL, 24-hour urine Ca 5 179 mg/d (Table 1), normal serum and urine protein electrophoresis and normal mammography. Parathyroid sestamibi scan showed increased activity posterior and inferior to the left thyroid lobe and a possible small focus of increased activity superior and inferior to the right thyroid lobe. Single photon emission computed tomography fusion images demonstrated uptake From the From the Department of Endocrine, University of Iowa, Iowa City, Iowa. Submitted February 22, 2013; accepted in revised form May 10, 2013. The author has no financial or other conflicts of interest to disclose. Correspondence: Cristina Ogrin, MD, the Department of Endocrine, University of Iowa, 200 Hawkins Drive, Iowa City, IA 52241 (E-mail: [email protected]).
432
within an ovoid soft tissue lesion inferior to the thyroid bed just left of midline and uptake within triangular-shaped soft tissue lesion just inferior to the right thyroid lobe (Figures 1A and 1B). No suspicion of lung cancer was found on contrast chest computed tomography. A right thyroid nodule was found at thyroid ultrasound (Figure 2) and was benign by fine needle aspiration. Bone densitometry revealed osteoporosis of lumbar spine with a T-score of lumbar spine of 22.5, whereas the T-score of total left hip was 21.8. She underwent successful resection of left and right inferior parathyroid glands, and her serum Ca 5 hours after surgery was 9.3 mg/dL. A rapid preoperative PTH from the right internal jugular (IJ) vein was 101 pg/mL. The left inferior parathyroid gland was removed first, and a rapid PTH measured 15 minutes after excision from the left IJ vein was 54 pg/mL. Then the right inferior parathyroid gland was removed, and a rapid PTH level measured 10 minutes after excision was reported as 27 pg/mL (right IJ) and 34 pg/mL (left IJ). Left inferior parathyroid was described as a tanyellow glandular appearing tissue (2.3 3 1.7 3 0.9 cm, weight of 2130 mg), and the right inferior was a pink and tan-yellow well-circumscribed tissue (2.4 3 1.3 3 1.0 cm, weight of 1510 mg). Specimens from the 2 glands removed showed similar histology: hypercellular parathyroid glands composed of a mixture of benign loose connective tissue and adipose tissue, separating cords of chief cells admixed with some oxyphilic cells, characteristic of parathyroid lipoadenomas (Figures 3A and 3B). The proportion of fat was roughly similar between the 2 glands, approximately 40%. Two months after surgery, her serum Ca, PTH and ALP normalized to 9.8 mg/dL, 32 pg/ mL and 108 IU/L, respectively. Parathyroid lipoadenomas are very rare variants of adenomas characterized histologically by an abundance of fat cells and are commonly nonfunctional.1,2 The origin of the fatty tissue component remains unknown, but it has been speculated that the same factors that drive the enlargement of the parathyroid chief cells are responsible for the enlargement of the fatty component. The World Health Organization defines a parathyroid lipoadenoma as a “hamartoma-like benign neoplasm containing both chief cells and prominent stromal elements.” Fat normally occupies approximately 25% of the normal parathyroid gland and may be increased by advanced age and obesity. Chow et al2 were able to identify 5 cases of functioning parathyroid lipoadenomas among 7,120 parathyroidectomies performed for primary hyperparathyroidism over a 30-year period in which fat content was described as .50%. However, the fat content in most published series of parathyroid lipoadenomas is highly variable.1,3,4 In the largest series of 11 cases (8 lipoadenomas and 3 lipohyperplasias), Seethala et al3 reported a median fat content of 50% (range, 30%–70%) in lipoadenomas and 60% (range, 10%–90%) in lipohyperplasia while the mean weights were 1.553 and 389.1 mg for lipoadenomas and lipohyperplasia, respectively. He concluded that accurate weight
The American Journal of the Medical Sciences
Volume 346, Number 5, November 2013
A Rare Case of Double Parathyroid Lipoadenoma With Hyperparathyroidism
TABLE 1. Serum parameters before and after parathyroidectomy Date Ca GFR PTH ALP GGT 9/15/11 9/20/11 12/1/11 1/25/12 4/12/12 4/12/12 6/13/12 Normal range
Bone ALP
25(OH)D
PO4
Ionized Ca
11.1 103 — 168 — — — — — 11.4 108 — 192 — — — — — 11.8 103 42 161 16 — — 3.1 6.6 11.9 103 60 — — 59.4 16.5 3.0 6.5 Patient underwent removal of right and left parathyroid glands 9.3 — — — — — — — — 9.8 128 32 108 — — 32 3.8 — 8.5–10.5 .60 mL/min 15–65 pg/mL 42–121 IU/L 6–65 IU/L 0–21.3 ug/L 30–100 ng/mL 2.7–4.5 mg/dL 4.5–5.6 mg/dL
ALP, alkaline phosphatase; Ca, calcium; GFR, glomerular filtration rate; GGT, gamma-glutamyl transferase; PO4, Phosphorus; PTH, parathyroid hormone; 25(OH)D, 25 hydroxyvitamin D.
FIGURE 1. (A) Fused SPECT/CT (sestamibi) coronal images depict uptake within triangularshaped soft tissue lesion just inferior to the right thyroid lobe (white arrow) and uptake within an ovoid soft tissue lesion just inferior to the thyroid bed just left of midline (white arrowhead). (B) Fused SPECT (sestamibi) axial images depict uptake within triangularshaped soft tissue lesion just inferior to the right thyroid lobe (white arrow) and uptake within an ovoid soft tissue lesion just inferior to the thyroid bed just left of midline (white arrowhead). CT, computed tomography; SPECT, single photon emission computed tomography.
documentation and recognition of key histological features help decrease the challenge of differentiation between lipoadenomas and lipohyperplasia. Clinical manifestations and the laboratory results in patients with functioning lipoadenomas are difficult to differentiate from those of the usual forms of primary hyperparathy-
FIGURE 2. Thyroid ultrasound (sagittal images) shows right thyroid nodule of 1.1 3 0.7 3 0.9 cm with multiple internal calcifications (white arrow). Ó 2013 Lippincott Williams & Wilkins
roidism. The first case of a functional parathyroid lipoadenoma causing hyperparathyroidism was described in 1962,4 and only a few others have been reported since then with the largest series of only 5 patients described by Chow et al.2–13 The unique feature of this case was the presence of 2 functional lipoadenomas located in the inferior right and left parathyroid glands. Lipoadenomas are more difficult to localize preoperatively by imaging due to high fat content. Ultrasound has been reported to identify the tumors in 50% of cases, whereas sestamibi was successful in 71% in a series of 11 cases.3 In our patient, ultrasound did not identify lipoadenomas, whereas sestamibi single photon emission computed tomography images showed increased activity in the left inferior parathyroid gland and a possible small focus of increased activity in the right inferior parathyroid gland. Weight of the right inferior lipoadenoma (1500 mg) was similar to the mean weight previously reported by Seethala et al,3 whereas the weight of the right inferior lipoadenoma was higher (2130 mg). Rapid preoperative PTH measured from right IJ vein was elevated at 101 pg/mL. Rapid PTH measured from both left and right IJ veins after excision of the left and right inferior glands demonstrated a significant decrease in PTH levels to 54 and 34 pg/mL, respectively. In addition to normalization of her serum calcium levels, intraoperative PTH measurement was useful in assessing the adequacy of parathyroidectomy. A significant decrease of the intraoperative PTH confirms that further exploration is not indicated.14
433
Ogrin
FIGURE 3. (A) Photomicrograph of parathyroid lipoadenoma shows hypercellular parathyroid glands composed of a mixture of benign loose connective and approximately 40% adipose tissue (black arrowhead) separating cords of chief cells admixed with some oxyphil cells, characteristic of parathyroid lipoadenomas. (Hematoxylin-eosin stain; low power magnification 310.) (B) Photomicrograph of parathyroid lipoadenoma shows hypercellular parathyroid glands composed of a mixture of benign loose connective and approximately 40% adipose tissue separating cords of chief cells (black arrowhead) admixed with some oxyphil cells, characteristic of parathyroid lipoadenomas (Hematoxylin-eosin stain; medium power magnification 340.)
Parathyroid lipoadenomas are rare tumors and uncommonly functional. Here, a unique case of primary hyperparathyroidism due to double parathyroid lipoadenoma is presented. REFERENCES 1. Weiland LH, Garrison RC, ReMine WH. Lipoadenoma of the parathyroid gland. Am J Surg Pathol 1978;2:3–7. 2. Chow LS, Erickson LA, Abu-Lebdeh HS, et al. Parathyroid lipoadenomas: a rare cause of primary hyperparathyroidism. Endocr Pract 2006;12:131–36. 3. Seethala RR, Ogilvie JB, Carty SE, et al. Parathyroid lipoadenomas and lipohyperplasias: clinicopathologic correlations. Am J Surg Pathol 2008;32:1854–67. 4. Abul-Haj SK, Conklin H, Hewitt WC. Functioning lipoadenoma of the parathyroid gland. Report of a unique case. N Engl J Med 1962;266:121–23. 5. Obara T, Fujimoto Y, Ito Y, et al. Functioning parathyroid lipoadenoma—report of four cases: clinicopathological and ultrasonographic features. Endocrinol Jpn 1989;36:135–45. 6. Bansal R, Trivedi P, Sarin J, et al. Lipoadenoma of the parathyroid gland—a rare cause of hyperparathyroidism. Gulf J Oncolog 2012;1:63–5.
434
7. Bleiweiss IJ, Harpaz N, Strauchen JA, et al. Functioning lipoadenoma of the parathyroid: case report and literature review. Mt Sinai J Med 1989; 56:114–17. 8. Uden P, Berglund J, Zederfeldt B, et al. Parathyroid lipoadenoma: a rare cause of primary hyperparathyroidism. Case report. Acta Chir Scand 1987;153:635–39. 9. de Leacy EA, Axelsen RA, Kleinman DS, et al. Functioning lipoadenoma of the parathyroid gland. Pathology 1988;20:377–80. 10. Ducatman BS, Wilkerson SY, Brown JA. Functioning parathyroid lipoadenoma. Report of a case diagnosed by intraoperative touch preparations. Arch Pathol Lab Med 1986;110:645–7. 11. Hargreaves HK, Wright TC Jr. A large functioning parathyroid lipoadenoma found in the posterior mediastinum. Am J Clin Pathol 1981; 76:89–93. 12. Wolff M, Goodman EN. Functioning lipoadenoma of a supernumerary parathyroid gland in the mediastinum. Head Neck Surg 1980;2: 302–7. 13. Daroca PJ Jr, Landau RL, Reed RJ, et al. Functioning lipoadenoma of the parathyroid gland. Arch Pathol Lab Med 1977;101:28–9. 14. Lee AY, Wang BY, Heller KS. Importance of intraoperative parathyroid hormone measurement in the diagnosis of parathyroid lipoadenoma. Head Neck 2011;33:917–9.
Volume 346, Number 5, November 2013