Indian Journal of Pathology and Microbiology

LETTER TO EDITOR
Year
: 2013  |  Volume : 56  |  Issue : 3  |  Page : 328--329

Double adenoma of the parathyroid: Reinforcing the existence of this entity


Sandhya Venkatachala1, S Rajesh Kumar2, S Premkumar2,  
1 Department of Pathology, PSG Institute of Medical Sciences and Research, Peelamedu, Coimbatore, Tamil Nadu, India
2 Department of Surgery, PSG Institute of Medical Sciences and Research, Peelamedu, Coimbatore, Tamil Nadu, India

Correspondence Address:
Sandhya Venkatachala
Department of Pathology, PSG Institute of Medical Sciences & Research, Peelamedu, Coimbatore - 641 004, Tamil Nadu
India




How to cite this article:
Venkatachala S, Kumar S R, Premkumar S. Double adenoma of the parathyroid: Reinforcing the existence of this entity .Indian J Pathol Microbiol 2013;56:328-329


How to cite this URL:
Venkatachala S, Kumar S R, Premkumar S. Double adenoma of the parathyroid: Reinforcing the existence of this entity . Indian J Pathol Microbiol [serial online] 2013 [cited 2022 May 25 ];56:328-329
Available from: https://www.ijpmonline.org/text.asp?2013/56/3/328/120420


Full Text

Sir,

A 37-year-old female with no known comorbidities came with complaints of muscle weakness over the face, extremities for the past 2 months and persistent vomiting from the preceding week. General physical examination and systemic examination revealed no abnormality. Biochemical investigations showed a raised serum calcium level of 12 mg/dl. Subsequently an ultrasound and magnetic resonance imaging (MRI) of the soft parts of the neck were performed. MRI revealed two soft-tissue masses, measuring 4 × 1.5 × 1.5 cm and 1.5 × 1.0 × 1.0 cm posterior inferior and posterior superior respectively to the right lobe of the thyroid gland suggesting a right parathyroid adenoma. Surgery was planned and pre-operative serum parathormone (PTH) levels were determined. An elevated serum PTH level of 223 pg/ml (normal range 15-65 pg/ml) was recorded.

On the operating table, MRI findings were confirmed. Right superior and inferior parathyroidectomy was performed. Both the parathyroids on the left side were grossly normal. PTH levels about 10 min following excision of both the enlarged glands was 65 pg/ml. The excised glands were sent for histopathological examination.

Right inferior parathyroid weighed 6 g, measured 3.0 × 2.3 × 0.3 cm [Figure 1]a and the right superior parathyroid weighed 0.8 g, measured 1.3 × 0.6 × 0.6 cm. Cut surface of both the glands were pale brown, firm and vaguely lobular. Microscopic examination of both the enlarged glands revealed capsulated neoplasms composed of polygonal cells arranged in solid sheets traversed by thin vascular septae [Figure 1]b. The cells exhibited distinct cytoplasmic borders, clear cytoplasm and round regular nuclei. Few cells with enlarged hyperchromatic nuclei were noted. The tumor cells showed regimentation of nuclei toward the vascular septae [Figure 1]c. Interspersed among these clear cells were seen cells with pale eosinophilic cytoplasm-oxyphil cells [Figure 1]d. There was no evidence of capsular or vascular invasion. A rim of normal compressed parathyroid tissue however could not be identified. These morphological features were correlated with clinical findings - grossly normal Left superior, inferior parathyroid glands at surgery and greater than 50% fall in serum PTH from the baseline levels. Thus, a diagnosis of double parathyroid adenomas was favored.{Figure 1}

 Discussion



The pathologic lesions causing primary hyperparathyroidism include solitary adenoma (80-85%), multigland hyperplasia (15%) and the rare carcinoma (1%). Double adenomas have been found in 2-15% of patients undergoing surgery for primary hyperparathyroidism. [1] The criteria for the diagnosis of multiple parathyroid adenomas have been defined by Harness and others as: (i) More than one and fewer than 4 enlarged parathyroid glands at operation (ii) operative finding of at least one normal parathyroid gland (iii) evidence of neither men or familial hyperparathyroidism and (iv) permanent normocalcemia after resection of enlarged parathyroid glands. [2] The current approach to the diagnosis of hyperparathyroidism is based on preoperative evaluation, intraoperative findings and pathological examination of parathyroid tissue. [3]

Our patient, a 37-year-old female with no family history of hyperparathyroidism presented with persistent vomiting and muscle weakness which along with bone pain are more common in patients with double adenoma than those with single adenoma or hyperplasia.

The excised right inferior and superior parathyroid was enlarged as determined by their weight (6 g 0.8 g respectively) and greatest dimension (3 cm, 1.3 cm respectively). The maximum permissible weight of each parathyroid gland is 60 mg and the permissible greatest dimension is 6 mm. [4] Double adenomas have been identified in different configurations. Both superior, both inferior, one inferior with contralateral superior, both left and both right (as seen in our case) have been described. [1] The classification of patients with more than 1 but less than 4 enlarged parathyroids as was seen in our case has been debated - whether the condition is double adenoma or asymmetric hyperplasia. [1]

The most reliable distinction between the two entities can be achieved by histological examination of the additional parathyroid glands. Hypercellularity with very few or no adipocytes distinguishes abnormal (hyperplasia/adenoma) from the normal parathyroid. Lipid staining in a frozen section to demonstrate the absence of intracytoplasmic lipid in hyperplastic or adenomatous cells has been suggested by some authors for this purpose. [4]

Histopathological examination and frozen section analysis are not completely reliable and always effective. [3],[4] Intra-operative parathyroid hormone measurement has been preferred to identify any residual hyperfunctioning parathyroid. [3] Thus, in our case, serum PTH and calcium levels were elevated preoperatively and following excision of both the enlarged parathyroids, the intraoperative PTH levels showed greater than 50% drop (from 223 pg/ml to 65 pg/ml), defining successful treatment. Normal calcium levels have been maintained over a yearlong follow-up.

The drop in the intraoperative levels of PTH, maintenance of normocalcemia both post-operatively and on long-term follow-up confirms previous reports that double adenomas do exist and are not simply missed cases of four-gland hyperplasia. Thus, identifying this entity avoids an unnecessary resection of normal parathyroid glands, thereby, preventing the risk of permanent hyperparathyroidism.

References

1Baloch ZW, LiVolsi VA. Double adenoma of the parathyroid gland: Does the entity exist? Arch Pathol Lab Med 2001;125:178-9.
2Harness JK, Ramsburg SR, Nishiyama RH, Thompson NW. Multiple adenomas of the parathyroids: Do they exist? Arch Surg 1979;114:468-74.
3Kandil E, Alabbas HH, Bansal A, Islam T, Tufaro AP, Tufano RP. Intraoperative parathyroid hormone assay in patients with primary hyperparathyroidism and double adenoma. Arch Otolaryngol Head Neck Surg 2009;135:1206-8.
4Yao K, Singer FR, Roth SI, Sassoon A, Ye C, Giuliano AE. Weight of normal parathyroid glands in patients with parathyroid adenomas. J Clin Endocrinol Metab 2004;89:3208-13.