Category: Calcium/Bone Disorders

Monitor: 22

22 - AN INTERESTING CASE OF LOW-GRADE PARATHYROID CARCINOMA

Saturday, Apr 27
10:30 AM – 11:00 AM

Objective : Parathyroid Carcinoma (PC) is a rare form of malignancy and accounts for <1% of cases of primary Hyperparathyroidism (PHT). It is challenging to diagnose PC due to the lack of specific clinical features and biochemical markers. Pathological diagnosis can be troublesome as well causing a delay in the ideal surgical treatment.


Methods : n/a


Results : n/a


Discussion :

A 39-year-old male with history of HTN, recurrent nephrolithiasis, asthma and drug abuse was involuntarily admitted to the hospital by his fiancé after a domestic fight. Labs at the time of presentation were significant for Ca13.2 mg/dl, Phos 2.8mg/dl, Mag 1.2 mg/dl, BUN 24 mg/dl, Cr 2 mg/dl. CT Brain and cervical spine showed multiple calcified discs with calcified bulges, along with diffusely hyperdense vertebral bodies and salt and pepper appearance of the cranial bones. In addition, a 2.7 x 2.3 x 4.5 cm mass near the posterior aspect of the left thyroid lobe concerning for parathyroid adenoma or thyroid neoplasm was reported.Further workup on hypercalcemia revealed intact PTH 194pg/ml, Ca 12.7mg/dl, Vit D25-OH 21ng/ml. Thyroid US and NM Parathyroid imaging confirmed a left parathyroid adenoma.The patient underwent parathyroidectomy, intraoperative PTH dropped from 233 to 64pg/ml. The patient was screened for MEN due to hyperparathyroidism and resistant hypertension. Gastrin, calcitonin, catecholamines were all within the normal range. During the surgery, a very large left superior parathyroid gland was noted with extension upto the level of the sternal notch without any local invasion. Gross pathologic examination of the surgical specimen showed a  enlarged, fragmented and hemorrhagic parathyroid gland (12.6 gm). Histologically, the tumor demonstrated uniform oxyphil cells with focal cellular atypia and low mitotic rate, divided by thick fibrous bands.  In addition, no definitive vascular invasion was seen, however, peripheral nerve entrapment was noted. Fragmentation of the specimen with limited representation of the tumor-stroma interface precluded accurate evaluation of capsular invasion and made this a difficult case to diagnose. An immunostain for parafibromin demonstrated abnormal loss of nuclear expression, a finding that is 95% specific for parathyroid carcinoma. Based on the combination of these atypical features, the loss of parafibromin staining, entrapment of peripheral nerve, and the markedly enlarged parathyroid, this lesion were best regarded as a low-grade parathyroid carcinoma. 


 


Conclusion :

PC is often a difficult pre-operative diagnosis and the patients are subjected to recurrent surgeries. Our patient underwent left thyroid lobectomy after the pathological confirmation of PC.

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Rachana Mundada

Internal Medicine Resident
Mercy Catholic Medical Center
Yeadon, Pennsylvania

I'm a third year medical resident and I matched to Endocrinology fellowship

Phillip Choi

Internal Medicine Resident
Mercy Catholic Medical Center

none

Edward Ruby

Faculty
Mercy Catholic Medical Center

Dr Ruby is an Endocrinology, Diabetes and Metabolism faculty at Mercy Catholic Medical Center.

Katarzyna Brzezinska

Pathology resident
Drexel University

Dr.Brzezinska is a pathology resident.

Randa Hennnawy

Pathology Faculty
Mercy Catholic Medical Resident

Dr. Hennawy is a pathology faculty at MCMC.