Vitamin D Deficiency and the Presentation of Primary Hyperparathyroidism: A Mini Review

The clinical presentation of primary hyperparathyroidism (PHPT) has evolved over the years from a symptomatic disorder to a predominantly asymptomatic condition. Altered vitamin D metabolism seems to play a role in the presentation of PHPT and may exacerbate the severity of disease. The epidemiology of PHPT differs in the developing versus the developed world, where more severe phenotypes occur in regions where vitamin D deficiency is common. Although it has been validated that patients with PHPT should be vitamin D sufficient, the threshold to supplement in relation to the severity of PHPT and the degree of vitamin D deficiency remains controversial. This review will highlight some of the controversy regarding vitamin D deficiency and the different phenotypes of PHPT.

Multiple myeloma presenting as acute tubulointerstitial nephritis

Background

Acute tubulointerstitial nephritis (ATIN) is a very rare paraneoplastic manifestation in patients with multiple myeloma (MM). It is an uncommon pattern of renal disease in such patients.

Case presentation

We report a case of an 82-year-old male who was admitted with acute kidney injury. Renal biopsy showed typical findings of light chain-associated ATIN with scattered inflammatory cells in the interstitium and associated active tubulitis. No other common manifestations of MM were present at the time of presentation, including hypercalcemia, hyperuricemia, proteinuria, bone pain or lytic bone lesions. Subsequent immunoassays revealed significant serum lambda light chain burden and Bence Jones protein in urine. Immunofluorescence demonstrated linear tubular basement membranes with positive staining for lambda light chain (3+). Electron microscopy (EM) further showed interstitial edema and inflammation. All the aforementioned findings are consistent with ATIN and supported the diagnosis of MM.

Conclusions

In conclusion, light chain-associated ATIN should be considered in the differential diagnosis of acute interstitial nephritis. Henceforth, serum free light chains as well as serum and urine protein electrophoresis should be included in the workup of such patients.

Appropriate Cutoff for 25OHD Levels in the Diagnosis of Normocalcemic Primary Hyperparathyroidism (NPHPT): A Systematic Review

Introduction: The Fourth International Workshop in 2014 delineated guidelines for the diagnosis of NPHPT which include ruling out secondary causes of hyperparathyroidism, and recommended cutoffs for 25 vitamin D (25OHD) to be ≥20ng/mL. Keeping in mind that the exact levels to optimize 25OHD in hyperparathyroid states are unknown, we aim to review possible variation in the prevalence of NPHPT if 25OHD cutoffs were to be raised to rule out vitamin D deficiency with more specificity. Methods: A PubMed search was conducted with key words “normocalcemic primary hyperparathyroidism” to review studies about NPHPT and 25OHD status. 533 articles were found, and 127 articles were identified by title/abstract screening with year of publication between 2014 to 2020. Ten studies were identified for the systematic review based on full text review for relevance. Results: Studies have been conducted in various countries across all continents to characterize NPHPT further. 5/10 studies used 25OHD cutoff of ≥20ng/mL and 4 studies had a cutoff of ≥30ng/mL and 1 study looked into the difference in prevalence with both cutoffs. All 3 studies from Italy used the higher cutoff. Rosario et al from Brazil reported a decrease in prevalence of NPHPT from 6.8% (25OHD≥20ng/mL) to 0.74% by supplementing those subjects to 25OHD ≥30ng/mL without any increase in serum calcium or parathyroid hormone (PTH) levels.1 Wang et al found that when total 25OHD levels were kept between 30–40 ng/mL, free 25OHD levels were actually lower compared to normal subjects.2 Conclusion: The levels of 25OHD that would define deficiency in NPHPT remain undetermined and both >20 ng/mL and >30ng/mL have been studied as cutoffs. It is well known that vitamin D insufficiency (25D 20-30ng/mL) drives up PTH and supplementation to 30-40ng/mL is required to reduce such effects. Wang et al suggest that free 25OHD levels correlate better with PTH as compared to total 25OHD and maybe a more reliable marker of 25OHD status. We suggest that a diagnostic criterion of ≥30ng/mL would be more appropriate in ruling out 25OHD deficiency in this special population. The role of free 25OHD levels in PHPT needs further evaluation. References: 1. Rosário PW, Calsolari MR. Normocalcemic Primary Hyperparathyroidism in Adults Without a History of Nephrolithiasis or Fractures: A Prospective Study. Horm Metab Res. 2019 Apr;51(4):243–247. doi: 10.1055/a-0859-1020. Epub 2019 Mar 6. PMID: 30840998. 2. Wang X, Meng L, Su C, Shapses SA. LOW FREE (BUT NOT TOTAL) 25-HYDROXYVITAMIN D LEVELS IN SUBJECTS WITH NORMOCALCEMIC HYPERPARATHYROIDISM. Endocr Pract. 2020 Feb;26(2):174–178. doi: 10.4158/EP-2019-0325. Epub 2019 Sep 26. PMID: 31557077

MON-382 An Adrenal Incidentaloma: The Dilemma over Dopamine

BACKGROUND: Pheochromocytomas are catecholamine secreting tumors that arise from the chromaffin cells of the adrenal medulla or from paraganglioma cells, in which case they would be extra-adrenal. They mostly secrete noradrenaline with or without adrenaline. A predominantly dopamine secreting tumor is extremely rare. About 35 cases of abdominal “dopaminomas” have been reported so far most of which are malignant. (1) They are believed to arise from enzymatic deficiency of dopamine beta-hydroxylase which converts dopamine to norepinephrine. CASE: A 65-year-old gentleman, with history of type 1 diabetes and ischemic cardiomyopathy was referred from urology for a pre-operative evaluation after being found to have a 1.4 cms, solid, enhancing right renal mass with an incidental finding of a 1.3 cms left adrenal nodule. An episode of diverticulitis had prompted an abdominal CT scan which revealed these findings. The patient denied any symptoms including hematuria, weight loss, episodic spells of dizziness, palpitations, sweating or headaches. Vitals and physical exam were otherwise unremarkable. Biochemical testing revealed plasma metanephrines of 38pg/ml(0-62), plasma normetanephrines of 62pg/ml(0-145), 24-hour-urine norepinephrine of 148ug(1-135), 24-hour-urine dopamine of 1778ug(0-510) with 8 am-serum-cortisol levels at 2.34ug/dl(5-22) . Adrenal protocol CT scan revealed a 1.4 cms left adrenal adenoma, regular borders with >50% washout at 10 minutes. Although dopaminomas have significant malignant potential, based on above the incidentaloma was thought to be benign. A diagnosis of Von-Hippel-Lindau was initially entertained until the patient underwent an uncomplicated right partial nephrectomy with pathology revealing a benign oncocytoma. CONCLUSION: Dopaminomas, apart from being extremely rare, could be missed as they are not routinely included in the workup of an adrenal mass. They could cause hypotension and/or bradycardia. Management differs significantly in terms of pre and post-op management from classic pheochromocytomas if adrenalectomy is to be pursued. Alpha and beta blockade isn’t required as dopamine acts via different receptors. Due to the malignant potential, follow up of dopamine levels and imaging should be done. Definitive treatment is surgery. Ref: Poirier É., Thauvette D., Hogue J.-C. Management of exclusively dopamine-secreting abdominal pheochromocytomas. Journal of the American College of Surgeons. 2013;216(2):340-346. doi: 10.1016/j.jamcollsurg.2012.10.002

SILICONE GRANULOMATOUS INFLAMMATION RESULTING IN HYPERCALCEMIA: A REVIEW OF THE LITERATURE

Objective

Silicone usage for cosmetic enhancement is common, although it is not approved by the U.S. Food and Drug Administration. Granulomatous inflammation leading to hypercalcemia is a rare complication. We present a case of non-parathyroid hormone (PTH), calcitriol-mediated hypercalcemia in a woman with a history of cosmetic injections.

Methods

Case report and review of the literature.

Results

A 48-year-old female with metabolic syndrome was evaluated for severe hypercalcemia (calcium >15 mg/dL). Laboratory tests revealed low-normal PTH, normal 25-hydroxyvitamin D, elevated 1,25-dihydroxyvitamin D, and hypercalciuria. Imaging studies, including a computed tomography (CT) scan of the lungs, was nonrevealing. Positron emission tomography/CT showed symmetric hypermetabolic subcutaneous stranding of bilateral gluteus and proximal thighs. She admitted to silicone injections in the buttocks 10 years prior. Her examination was unremarkable except for an intermittent pruritic rash over the right thigh. Labs revealed total serum calcium 11.3 mg/dL, PTH 18 pg/mL, 24-hour urinary calcium 509 mg, and PTH-related peptide 18 pg/mL. Serum and urine electrophoresis were normal, 25-hydroxyvitamin D was 47 pg/mL, and 1,25-dihydroxyvitamin D was 121 pg/mL. Angiotensin-converting enzyme level was 80 U/mL. A diagnosis of granulomatous inflammation resulting in calcitriol-mediated, PTH-independent hypercalcemia was entertained.

Conclusion

Silicone-induced hypercalcemia should be thought of in those with prior cosmetic injections. Tissue biopsy confirms the diagnosis, which is often delayed. We reviewed 19 cases with silicone usage and variable levels of hypercalcemia. Renal injury was common. One death was reported. Glucocorticoids, calcium restriction, and hydration have been used to treat calcitriol-mediated hypercalcemia but are not curative. Ketoconazole and bisphosphonates have been used with variable success. Surgical excision tends to be ineffective due to silicone migration. The treatment of this disorder is difficult and often ineffective.

Thyroid Abscess: Challenges in Diagnosis and Management

Thyroid abscess is an uncommon infectious pathology. The thyroid is highly resistant to infection due to high iodine content, capsular encasement, and rich vascularity. Acute suppurative thyroiditis represents <1% of thyroid diseases that could potentially become a life-threatening endocrine emergency. A 48-year-old woman with AIDS presented with 3 days of fever, tender neck swelling, and methicillin-resistant Staphylococcus aureus bacteremia. Apart from leukocytosis, initial laboratory values including thyroid function tests were normal. The initial plain computed tomography scan of the neck and ultrasound scan of the neck were inconclusive as well. By day 4, she worsened, and on repeat computed tomography scan of the neck with contrast, multiloculated abscesses in the thyroid and retro pharynx were seen, which needed emergent drainage. Acute suppurative thyroiditis, a rare disease, occurs in patients with either preexisting disorders of the thyroid or in the immunocompromised. The most common pathogen is Staphylococcus aureus. In our case, we highlight the fact that initial imaging may be negative in the early stages of acute suppurative thyroiditis and lead to an erroneous diagnosis of subacute thyroiditis. There are less than 5 cases of methicillin-resistant Staphylococcus aureus suppurative thyroiditis reported.

Hemoglobin E disease and glycosylated hemoglobin

Glycosylated hemoglobin (HbA1C) is a routinely measured parameter to monitor long-term glycemic control in people with diabetes mellitus. The presence of hemoglobin (Hb) variants can affect the accuracy of HbA1C methods. Hb E variant is the most common Hb variant in South-east Asia and North-east India. In the presence of Hb E, HbA1C may not be detectable by ion-exchange chromatography (high-pressure liquid chromatography), but may be estimated by immunoassay technique and boronate affinity chromatography. However, the result may be underestimated when correlated with plasma glucose and serum fructosamine levels. Clinicians should be aware of this limitation of HbA1C estimation in patients with Hb E and other Hb variants.