Multiple endocrine neoplasia type 2A: a case report and literature review

Abstract

Objective To improve the diagnosis and treatment of multiple endocrine neoplasia type 2A (MEN 2A).Methods We have retrospectively reviewed one case of MEN 2A,admitted in our hospital on August 22th,2011.A 38-year-old female admitted due to headache,palpitation,sweating with the CT image of left adrenal tumor for 1 month.Her blood pressure was 200/100 mmHg.Multiple firm thyroid nodules were felt,and there was no abnormal in the abdomen.Endocrine examination revealed high catecholamines:norepinephrine 4.09 nmol/L,epinephrine 0.54 nmol/L,and dopamine 0.53 nmol/L.Parathormone was 216.7 ng/L.Abdominal ultrasound showed a 9 cm cystic solid mass located in the left adrenal area.The border line of mass was clear.And the spetum was noticed in the cystic part.In the solid part,no blood flow was observed.CT scan revealed a large well defined mass lesion (8.5 cm) in left adrenal area with obvious enhanced,and left renal agenesis (2 cm×1 cm).131Ⅰ-MIBG was positive for the pheochromocytoma.The cervical ultrasound showed multiple nodulars in the thyroid with rich blood supply,which was considered as thyroid carcinoma.And the CT examination also demonstrated the multiple low density solid mass in the thyroid with mild enhancement.No lymphadenopathy was observed in the neck.Preoperative diagnosis was the left adrenal pheochromocytoma,medullary thyroidcarcinoma,parathyroid hyperplasia,and left renal agenesis.The patient was undergone laparoscopic adrenalectomy with general anesthesia.There were fluctuations in the patient's blood pressure during operation.The systolic blood pressure (SBP) ranged from 80 to 230 mmHg.The neoplasm was completely resected.Results The operative time was 130 minutes,and blood loss was 50 ml.The tumor had a well-defined capsule (8.5 cm in diameter).The cross section of the tumor showed liquefactive necrosis inside the mass.The microscopic observation revealed that chromaffin cells were found to be arranged as cell nests and showed moderate heteromorphism.Immunohistochemically,the tumor cells were positive for chromogranin A,neuron-specific enolase,S-100,synaptophysin,Vimentin,Melan-A.Ki-67 labeling was approximately 5％.The tumor cells were negative for CD34 and cytokeratins.Histopathologic examination demonstrated a pheochromocytoma.The following day,her blood pressure was 110/70 mmHg.One week later,the elevated serum nor-metanephrine levels dropped to the normal range.After one month,open thyroidectomy with neck lymph node dissection and parathyroidectomy were operated on the patient.Histopathologic examination demonstrated a medullary thyroid carcinoma and parathyroid hyperplasia.Medullary cancer metastases were found in one of six lymph nodes.After surgery,the patient was given adequate thyroid hormone and calcium supplementation.Genetic Analysis showed the RET mutation observed in the patient and her relatives at codon 634 (exon 11) was TGC→CGC.After a 1-year follow-up,the patient was alive with normal blood pressure and with no evidence of recurrent.Conclusions When pheochromocytoma is concomitant with thyroid carcinoma and parathyroid hyperplasia/adenoma,MEN 2A should be considered.Genetic analysis is the best way to approve the diagnosis.Operations,concerning the pheochromocytoma and medullary thyroid carcinoma,should be performed earlier. Key words: Multiple endocrine neoplasia type 2A; RET proto-oncogene; Pheochromocytoma; Medullary thyroid carcinoma; Renal agenesis