Incidentally detected primary hyperparathyroidism.

Sir,

A 26-year-old male patient was referred to the radiology department for high-resolution computed tomographic (HRCT) examination of the chest due to recurrent respiratory complaints. HRCT of the thorax was performed which showed patchy area of consolidation in the left upper lobe which was consistent with infective etiology [Figure 1a]. However, the spine, sternum, scapula, and ribs showed changes of diffuse osteosclerosis on the bone window setting [Figure 1b]. Visualized cuts of the neck revealed a well-defined hypodense nodular lesion located posterior to the left lobe of thyroid [Figure 2]. The presence of typical skeletal changes and nodular lesion in the location of left parathyroid gland raised the suspicion of parathyroid adenoma causing hyperparathyroidism. To support the diagnosis, various blood investigations were performed and conventional radiographs of the lateral view of skull and the anteroposterior view of bilateral hands were taken.

Figure 1

(a) Computed tomographic image of the thorax in coronal view showing area of consolidation with internal cavitation in left upper lobe (arrow). (b) Mid-sagittal view of the thorax in bone window setting showing changes of diffuse osteosclerosis involving spine (arrow) and sternum (arrowhead)

Figure 2

Computed tomographic sagittal section of neck showing a well-defined hypodense nodular lesion (arrow) located posterior to the left lobe of thyroid (t) suggestive of parathyroid adenoma

Lateral radiograph of the skull revealed the presence of multiple tiny well-defined lucencies with loss of definition between the inner and outer table giving typical salt and pepper appearance. Anteroposterior radiograph of the bilateral hands revealed subperiosteal bone resorption in radial aspects of the proximal and middle phalanges of the second and third digits with acroosteolysis [Figure 3]. Ultrasound evaluation of the neck revealed the presence of well-defined nodular lesion measuring 2 cm × 1.4 cm × 1.4 cm in the expected location of left parathyroid gland with increased internal vascularity. Abdominal ultrasound examination revealed bilateral nephrolithiasis and hydronephrosis [Figure 4]. On further interrogation, the patient admitted the complaints of increased urinary frequency, burning micturition, generalized body ache, and lethargy. There was no significant medical or surgical history.

Figure 3

(a) Lateral radiograph of the skull revealed the presence of multiple tiny well-defined lucencies with loss of definition between the inner and outer table giving typical salt and pepper appearance. (b) Anteroposterior radiograph of the bilateral hands revealed subperiosteal bone resorption in radial aspects of the proximal and middle phalanges of the second and third digits (arrows) with acroosteolysis (circles)

Figure 4

(a and b) Ultrasound evaluation of the neck revealed the presence of well-defined nodular lesion measuring 2 cm × 1.4 cm × 1.4 cm in the expected location of left parathyroid gland with increased internal vascularity. (c) Abdominal ultrasound examination showing hydronephrosis with renal calculus

Laboratory data revealed extremely elevated parathyroid hormone levels (1978 pg/ml), elevated calcium levels (11.6 mg/dl), slightly decreased serum phosphorus level (2 mg/dl), elevated urea (150 mg/dl), creatinine (6.44), and alkaline phosphatase (723 U/L). Provisional diagnosis of primary hyperparathyroidism due to parathyroid adenoma was made, and surgical excision of the adenoma was planned.

Primary hyperparathyroidism is a relatively common endocrine disorder, mostly caused by solitary parathyroid adenoma (85% cases) followed by parathyroid hyperplasia and rarely due to parathyroid carcinoma.[1] Most of the patients are asymptomatic. Previously encountered overt symptoms such as abdominal pain due to renal calculi, pancreatitis, and peptic ulcer disease are less common and so are the diffuse bone and joint pain. The classic imaging findings of advanced primary hyperparathyroidism are now less frequently seen.[2]

Generalized osteopenia is the most common imaging finding in primary hyperparathyroidism. Osteosclerosis is a more common finding in secondary hyperparathyroidism and is very rarely seen with the primary one. Classical stripped appearance of the affected spine is called as “Rugger jersey” spine. Subperiosteal bone resorption at the radial aspects of the second and third middle phalanges with acroosteolysis is the most common finding in hands and feet. Salt and pepper sign or pepper pot skull refers to resorption of the trabecular bone, leading to multiple tiny well-defined lucencies in the calvaria with loss of definition between the outer and inner tables of the skull.[34]

Our patient underwent surgical excision of parathyroid adenoma. Transient hypocalcemia in the immediate postoperative period was treated with calcium supplements. The patient had an uneventful hospital course. Plans are to continue current management with calcium supplementation and observation.

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Conflicts of interest

There are no conflicts of interest.