Thallium 201 scanning can diagnose multiple recurrences in forearm implanted parathyroid tissue post total parathyroidectomy:

Wagih, Sherin

doi:10.21608/egyjnm.2011.5494

Thallium 201 scanning can diagnose multiple recurrences in forearm implanted parathyroid tissue post total parathyroidectomy:

Document Type : Case Presentation

Author

Sherin Wagih

King Abdulla Medical City, Nuclear medicine department and Oncology Center*

10.21608/egyjnm.2011.5494

Abstract

We report a case of a 48 years old male known to have chronic renal failure for more than 17 years. Patient was on regular haemodialysis for the last eleven years post failure of renal transplant due to graft rejection. Patient developed secondary hyperparathyroidism .He underwent total parathyroidectomy (surgical removal of the four parathyroid glands) with reimplantation of parathyroid tissue in the proximal right forearm in July 2009. Three months later, In November 2009, serum parathormone level (PTH) was elevated reaching up to 766pg/ml (N: 15-65 pg/ml) .Patient was operated upon for removal of the implanted tissue in the right forearm (no available preoperative diagnostic imaging modalities). Gross description in histopathology was two pieces of tissue representing two nodules each2X1 cm. Microscopically, the picture was consistent with chief cell hyperplasia .Post operatively both serum calcium and parathormone levels were normalized (Jan.2010). First presentation to king Abdulla Medical city was in August 2010, patient presented with mildly tender small swelling in proximal right forearm associated with intermittent generalized bony pains. Laboratory data revealed hypercalcemia (serum calcium level: 3.4 mmol/L -N:2.1-2.5 mmol/L)with markedly elevated serum PTH level (2184pg/ml) . CT scan of right forearm revealed presence of a nodular enhancing lesion of 29X11.6X7.7 mm with well defined margin in the site of implantation at lateral (radial) aspect of proximal right forearm just underlying the skin. Thallium201(TL201) scan revealed a well defined TL201 avid lesion located at lateral aspect of proximal right forearm just below the scar (Fig1). Besides, it revealed absence of any TL201 uptake that may represent overfunctioning parathyroid tissue neither in the neck nor in the mediastinum.(Fig 2) Patient was operated upon by removal of the lesion in the forearm for the second time (September2010). Histopathology proved to be parathyroid hyperplasia (Fig3). Post operative serum PTH level was still elevated (416.2 pg/ml) with persistent hypercalcemia (2.83 mmol/L). TL201 scan was repeated in January 2011. It revealed presence of small linear TL201 avid lesion in proximal right forearm (Fig4). Again, no TL201 avid lesions depicted in the neck or in mediastinum that may represent overfunctioning parathyroid tissue at normal anatomical sites of parathyroid glands nor at any expected ectopic site. The patient was reoperated upon with re-excision of the lesion in the right forearm for the third time. Again, Histopathology proved to be parathyroid hyperplasia. Serum partarthormone level at 2 months post surgery (March 2011) was 20.2pg/ml(N:15-65),with normal serum calcium level 2.2mmol/L. Patient is under regular follow up with normal serum calcium and parathormone levels till September 2011.