Sarat Sunthornyothin

Bilateral pheochromocytoma during the postpartum period

BackgroundPheochromocytoma manifesting during pregnancy is uncommon but it is responsible for a high maternal and fetal mortality rate, especially when unrecognized. Most cases of pheochromocytoma are sporadic but they can be part of hereditary autosomal dominant syndromes.CaseWe describe a case of bilateral pheochromocytoma in a term-pregnant patient with a previous history of medullary thyroid carcinoma (MTC). Her genetic study revealed a heterozygous mutation, c.1900T>C, in the RET proto-oncogene which confirmed the diagnosis of multiple endocrine neoplasia type 2A (MEN2A). Unrecognized, the tumors caused a crisis with fatal outcome in the mother during the postpartum period. This event might have been prevented if the tumor had been detected previously.ConclusionMEN2A affected pregnancy is an unusual condition. This syndrome should be suspected when a pregnant patient has a history of MTC. Early detection and appropriate management can prevent serious maternal and fetal complications. We also reviewed the literature of MEN2A-affected pregnancies.

Two common and three novel PDS mutations in Thai patients with Pendred syndrome

Pendred syndrome is an autosomal recessive disorder characterized by congenital sensorineural deafness, goiter, and impaired iodide organification. It is caused by mutations in the PDS gene. Most published mutation studies of Pendred syndrome have dealt with Western populations. In this study, we examined clinical and molecular characteristics of 16 affected individuals in 6 unrelated Thai families. Of all the affected, 100% (16/16) had bilateral deafness, 68.8% (11/16) goiters, and 25% (4/16) hypothyroidism. Follicular thyroid carcinoma and Hürthle cell adenoma were found in affected members of a family, raising the possibility of an increased risk of thyroid carcinoma in Pendred syndrome patients. Sequence analysis of the entire coding region of the PDS gene successfully identified all 12 mutant alleles in these 6 families. The 12 identified mutant alleles constituted 6 distinct mutations including 3 splice site mutations (IVS4-1G>A, IVS7-2A>G, IVS9-1G>A), one frame shift mutation (1548insC) and 2 missense mutations (T67S, H723R). Eight mutations out of 12 were constituted by IVS7-2A>G and 1548insC, each one being present in 4 distinct alleles in our studied group. The identification of these two frequent PDS mutations will facilitate the molecular diagnosis of Pendred syndrome in Thai populations. In addition, three newly identified mutations, T67S, IVS4-1G>A, and IVS9-1G>A, were not observed in 50 unrelated healthy Thai controls.

Clinical characteristics of diabetic ketoacidosis in newly diagnosed adult patients

A retrospective review was conducted of medical records of newly diagnosed diabetes in adults who presented with DKA between 2003 and 2007. The majority of DKA in Thailand could not be classified as classical type 1 diabetes. Some newly diagnosed people presenting with DKA could be safely withdrawn from insulin treatment.

Prevalence of Somatic KCNJ5 Mutations in Thai Patients With Aldosterone-Producing Adrenal Adenomas

Abstract Somatic KCNJ5 mutations result in excess aldosterone production and are reported to be more common in Asia than elsewhere. To assess the prevalence of somatic KCNJ5 mutations in Thai patients with aldosterone-producing adrenal adenomas (APAs) in a single tertiary center, we analyzed the paraffin-embedded tissue of KCNJ5 mutations from 96 patients with sporadic APAs who underwent unilateral laparoscopic adrenalectomy at our center during 2007 to 2016. We also assessed the clinical characteristics, treatment outcomes, and biochemistry and histologic differences among patients with and without somatic KCNJ5 mutations. Of the 96 patients with APA, 67 (70%) had somatic mutations of the KCNJ5 gene: 39 patients with p.G151R, 26 patients with p.L168R, one patient with p.T158A, and one patient with p.W126R. All patients presented with hypertension. Hypokalemia was documented in 98% of patients. The hypertension cure rate at 1 year after surgery was 35%. Patients with somatic KCNJ5 mutations required more potassium supplementation and had adrenal histology compatible with zona fasciculata–like cells compared with patients without the mutations (all P < 0.05). There were no significant differences in preoperative plasma aldosterone concentration (PAC), plasma renin activity, aldosterone/renin ratio, potassium level, treatment of hypertension, tumor size, and hypertension cure rate among patients in the KCNJ5-mutant and nonmutant groups. In a multivariate analysis, a higher PAC was associated with the presence of somatic KCNJ5 mutations. In summary, the prevalence of somatic KCNJ5 mutations in patients with sporadic APAs in Thailand, an Asian country with residents of different ethnic backgrounds, is comparable to previous reports in Asia.

Renal infarction associated with adrenal pheochromocytoma.

The coexistence of pheochromocytoma and renal artery stenosis had been reported occasionally from the possible mechanism of catecholoamine-induced vasospasm and extrinsic compression of renal artery in some reported cases. However, renal infarction caused by pheochromocytoma is an uncommon phenomenon. Herein, we report an interesting case of adrenal pheochromocytoma associated with renal artery thrombosis, which should be included in the differential diagnosis of pheochromocytoma patients who present with abdominal pain.