Summary

Unlike medullary thyroid carcinomas, follicular cell-derived thyroid malignancies have rarely been associated with paraneoplastic endocrine syndromes. An ultrarare case of a middle-aged man with heavily treated broadly metastatic radioactive iodine-refractory widely invasive Hürthle cell carcinoma (HCC) of the thyroid with two synchronous paraneoplastic endocrine syndromes, T3 thyrotoxicosis and hypercalcemia of malignancy, is discussed here. The levothyroxine-induced T3 thyrotoxicosis was a gradual process that became more noticeable as the tumor burden, refractory to different modalities of therapy, expanded. The 1,25-dihydroxyvitamin-D-mediated hypercalcemia, on the other hand, developed in a manner of weeks, as it usually happens. It is important to emphasize that in patients with metastatic Hürthle cell and follicular carcinomas of the thyroid, on TSH suppressive therapy, the unexplained and progressive decline in FT4 and rise in FT3 levels, resulting in an elevated FT4/FT3 ratio, could be an indication of augmented type 1 (D1) and/or type 2 (D2) deiodinase expression in tumoral tissue, causing an increased conversion from the prohormone T4 into the active metabolite T3 via outer ring deiodination.

Learning points

• Albeit extremely rare, some patients with thyroid cancer can present with more than one concomitant paraneoplastic syndrome.

• Although medullary thyroid carcinoma is the thyroid malignancy that is usually associated with paraneoplastic endocrine syndromes, follicular cell-derived thyroid cancers have been rarely described as being the culprit.

• In patients with metastatic Hürthle cell and follicular thyroid carcinomas, the unexplained and progressive decline in FT4 and rise in FT3 levels could be an indication of augmented type 1 (D1) and/or type 2 (D2) deiodinase expression in tumoral tissue, causing an increased conversion from T4 into T3 leading to T3 thyrotoxicosis.

Summary

Pheochromocytomas are rare adrenal tumors characterized by excessive catecholamine secretion. Symptoms and signs associated with pheochromocytomas are usually intermittent and chronic but can rarely develop into life-threatening crises. We describe a case of acute severe congestive heart failure in a previously healthy female, who recovered rapidly (4 days after admission) with acute medical therapy. The etiology on evaluation was a spontaneous bleed in a previously undiagnosed pheochromocytoma, resulting in a pheochromocytoma crisis and transient stress cardiomyopathy, followed by quick recovery of cardiac function. Our aim is to describe pheochromocytoma as a rare cause of stress cardiomyopathy. We discuss the evaluation of pheochromocytoma during critical illness and triggers/treatment strategies for pheochromocytoma crises.

Learning points

• Hemorrhage in a pheochromocytoma can result in a pheochromocytoma crisis, with sudden release of excess catecholamines resulting in multisystem organ dysfunction and high mortality.

• Acute decompensated heart failure can be a rare presentation of pheochromocytoma, in a patient with no cardiac risk factors.

• Measurement of metanephrines in acutely stressful clinical situations can have considerable overlap with the biochemical picture of pheochromocytoma. Early imaging studies may help with the differential diagnosis.

• Pheochromocytoma should be ruled out before performing an adrenal biopsy.

• Emergent adrenalectomy in pheochromocytoma crisis results in high mortality. Medical management of the acute crisis followed by elective adrenalectomy after alpha-blockade results in better outcomes.

Summary

New-onset primary adrenal insufficiency is rare in pregnancy. The symptoms of adrenal insufficiency such as nausea, vomiting and dizziness may be attributed to the pregnancy itself, which can lead to a delay in the diagnosis. The presence of hypotension, hypoglycemia or hyperkalemia should raise the suspicion for adrenal insufficiency. We report the case of a 25-year-old woman who presented with tachycardia, left flank pain and vomiting at 36 weeks’ gestation. She was found to have primary adrenal insufficiency and started on hydrocortisone and fludrocortisone with resolution of the vomiting and tachycardia. MRI of the abdomen revealed an acute nonhemorrhagic infarct of the left adrenal gland. The contralateral adrenal gland was normal. Autoimmune and infectious etiologies of primary adrenal insufficiency were ruled out and the adrenal insufficiency was attributed to the unilateral adrenal infarction. Adrenal insufficiency persisted after delivery and then resolved at approximately 16 months post partum. This case highlights the need to test women with unilateral adrenal infarction in pregnancy for the presence of primary adrenal insufficiency.

Learning points

• Adrenal insufficiency should be considered when a pregnant woman develops nausea, vomiting and dizziness in association with hypotension or hypoglycemia. Hypovolemic hyponatremia related to vomiting can occur in pregnancy, but the failure to correct hyponatremia despite adequate IV hydration should raise the suspicion for adrenal insufficiency.

• Adrenal infarction should be in the differential diagnosis for unilateral flank pain in pregnancy. Other common etiologies for flank pain in pregnancy include nephrolithiasis, pyelonephritis and acute cholecystitis.

• Unilateral adrenal infarction in pregnancy can lead to the development of primary adrenal insufficiency. Following delivery, these patients need to be monitored for the resolution of the adrenal insufficiency.

Summary

An 11-year-old girl with past medical history of septic shock and multi-organ failure at age 5 presented to her primary care doctor with concern for pallor of the lips. Laboratory studies demonstrated low free thyroxine (T4) and normal thyroid-stimulating hormone (TSH). A referral to endocrinology was made where the patient was evaluated, and laboratory evaluation was repeated. The patient was asymptomatic and clinically euthyroid with a height consistent with her mid-parental height and was in mid- to late-puberty. The repeated laboratory evaluation demonstrated a pattern suggestive of primary hypothyroidism with low free T4 and an elevated TSH. However, the magnitude of elevation of TSH was less than expected, given the degree of lowering of free T4; therefore, central hypothyroidism was considered. Workup was initiated, and laboratory studies and MRI imaging confirmed an underlying diagnosis of panhypopituitarism in the setting of pituitary stalk interruption syndrome.

Learning points

• Pituitary stalk interruption syndrome is a rare but important cause of panhypopituitarism.

• Central hypothyroidism should be suspected in patients with low free thyroxine with an inappropriate degree of elevation of thyroid-stimulating hormone.

• Workup of central hypothyroidism should include multi-pituitary hormone assessment, and, if evident, MRI imaging should be done.

• Adrenal insufficiency should be suspected in a hypotensive, critically ill patient who is failing to improve on standard-of-care therapy.

Summary

Mitochondrial diseases are a group of rare diseases presenting with heterogeneous clinical, biochemical, and genetic disorders caused by mutations in the mitochondrial or nuclear genome. Multiple organs can be affected, particularly those with high energy demand. Diabetes is a common endocrine manifestation of mitochondrial diseases. The onset of mitochondrial diabetes can be latent or acute, and the presenting phenotype can be type 1- or type 2-like. Studies show that diabetes ais associated with latent progression of cognitive decline in patients with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Herein, we report a case of rapid cognitive decline after the acute onset of diabetes in a patient with MELAS syndrome. The patient was a 36-year-old woman who was hospitalized due to hyperglycemic crisis and seizures. She was diagnosed with MELAS syndrome two years previously, and had gradually progressing dementia and hearing loss. However, following the acute onset of diabetes, she developed rapid cognitive decline and loss of ability to perform daily activities. In conclusion, the acute onset of diabetes could be an associated risk factor for rapid cognitive decline in patients with MELAS syndrome. Thus, these patients as well as healthy carriers with related genetic mutations should undergo diabetes education and screening tests. Moreover, clinicians should be aware of the possibility for acute onset of hyperglycemic crisis, particularly in the presence of triggering factors.

Learning points

• Diabetes is a common endocrine manifestation of mitochondrial diseases, presenting with a type 1- or type 2-like phenotype depending on the level of insulinopenia.

• Metformin should be avoided in patients with mitochondrial diseases to prevent metformin-induced lactic acidosis.

• Mitochondrial diabetes can manifest before or after the onset of MELAS syndrome.

• In patients with MELAS syndrome, diabetes can initially manifest with a life-threatening severe hyperglycemic crisis and can cause rapid cognitive decline.

• Diabetes screening tests (e.g. hemoglobin A1c, oral glucose tolerance test, or random blood glucose level measurement) should be performed either systematically or in the presence of symptoms, particularly after triggering events.

• Genetic testing and counseling should be provided to patients and their families for the purpose of better understanding the inheritance, progression, and possible outcomes of the disease.

Summary

Kallmann syndrome (KS) is a genetically heterogeneous condition characterized by hypogonadotropic hypogonadism with coexisting anosmia or hyposmia along with potential other phenotypic abnormalities depending on the specific genetic mutation involved. Several genetic mutations have been described to cause KS. The ANOS1 (KAL1) gene is responsible for 8% of mutations causing KS. A 17-year-old male presented to our clinic with delayed puberty and hyposmia, along with a family history suggestive of hypogonadism in his maternal uncle. Genetic testing for KS revealed complete exon 3 deletion in the ANOS1 gene. To the best of our knowledge, this specific mutation has not been previously described in the literature.

Learning points

• Missense and frameshift mutations in the KAL1 or ANOS1 gene located in the X chromosome are responsible for 8% of all known genetic mutations of Kallmann syndrome.

• Exon 3 deletion is one of the ANOS1 gene is a novel mutation, not reported before.

• Targeted gene sequencing for hypogonadotropic hypogonadism can be employed based on the phenotypic presentation.

Summary

Neonatal hypoglycemia is a serious condition that can have a major impact on the growing neonatal brain. The differential diagnosis of neonatal hypoglycemia is broad and includes hyperinsulinism as well as panhypopituitarism. The FOXA2 gene has been involved in the development of the pancreas as well as the pituitary gland. Six cases have been reported thus far with FOXA2 mutations presenting with variable degrees of hypopituitarism, and only two patients had permanent hyperinsulinism; other cases have been reported with microdeletions in 20p11, the location that encompasses FOXA2, and those patients presented with a wider phenotype. A full-term female infant presented with severe hypoglycemia. Critical sampling showed an insulin of 1 mIU/mL, suppressed beta-hydroxybutyric acids, and suppressed free fatty acids. Blood glucose responded to glucagon administration. Growth hormone (GH) stimulation test later showed undetectable GH in all samples, and cortisol failed to respond appropriately to stimulation. Gonadotropins were undetectable at 1 month of life, and MRI showed ectopic posterior pituitary, interrupted stalk, hypoplastic anterior pituitary, cavum septum pellucidum, and diminutive appearance of optic nerves. Whole-exome sequencing revealed a likely pathogenic de novo c.604 T>C, p.Tyr202His FOXA2 mutation. We expand the known phenotype on FOXA2 mutations and report a likely pathogenic, novel mutation associated with hyperinsulinism and panhypopituitarism.

Learning points

• FOXA2 has been shown to play an important role in the neuroectodermal and endodermal development.

• FOXA2 mutation may lead to the rare combination of hyperinsulinism and panhypopituitarism.

• Patients reported so far all responded well to diazoxide. Dysmorphology may be subtle, and liver functions should be monitored.

Summary

We report a rare case of biopsy-proven isolated immunoglobulin G4 (IgG4)-related hypophysitis and Rathke’s cleft cyst (RCC) presenting as panhypopituitarism. A 54-year-old Caucasian female presented with symptoms of slurred speech, altered mental status, polyuria and polydipsia and was found to have panhypopituitarism. Brain MRI showed a suprasellar mass with suspected intralesional hemorrhage. She underwent trans-sphenoidal resection due to MRI evidence of compression of the optic chiasm and left optic nerve. Preoperatively, she was started on hydrocortisone, levothyroxine and desmopressin. Histopathology demonstrated a RCC with adjacent lymphoplasmacytic hypophysitis with numerous IgG4-immunoreactive plasma cells. Hydrocortisone was stopped at 10 months after confirming hypothalamic-pituitary-adrenal (HPA)-axis recovery and desmopressin was stopped at 1 year. There was recurrence of a cystic mass at 1 year follow-up. Over 4 years of follow-up, she continued to require levothyroxine, and the mass remained stable in size. In order to begin to understand how this case’s unique histopathological presentation influences clinical presentation, pituitary imaging and prognosis, we present an accompanying literature review.

Learning points

• Isolated IgG4 hypophysitis and coexisting Rathke’s cleft cyst is a rare condition, which presents a diagnostic challenge.

• Recognizing its characteristic features can assist with early recognition and initiation of therapy to promote optimal outcomes.

• Further studies investigating the mechanisms promoting co-occurrence of these entities and their effect on prognosis are needed.

Summary

Multiple research studies address the anti-insulinemic effect of growth hormone (GH). We report a case of a patient with anterior hypopituitarism on GH replacement who later developed type 1 diabetes mellitus (T1DM). Recombinant human growth hormone (rhGH) therapy was discontinued at the time of growth completion. Because of significantly improved glycemic control, this patient was weaned off subcutaneous insulin. He regressed from stage 3 to stage 2 T1DM and remained in this status for at least 2 years and until the writing of this paper. The diagnosis of T1DM was established based on relatively low C-peptide and insulin levels for the degree of hyperglycemia as well as seropositivity of zinc transporter antibody and islet antigen-2 antibody. Additional laboratory data obtained 2 months after discontinuing rhGH revealed improved endogenous insulin secretion. This case report calls attention to the diabetogenic effect of GH therapy in the setting of T1DM. It also demonstrates the possibility of regression from stage 3 T1DM requiring insulin therapy to stage 2 T1DM with asymptomatic dysglycemia after discontinuing rhGH.

Learning points

• Given the diabetogenic effect of growth hormone, blood glucose levels should be monitored in patients with type 1 diabetes mellitus (T1DM) on insulin therapy and recombinant human growth hormone (rhGH) replacement.

• Clinicians should closely monitor for risk of hypoglycemia after discontinuing rhGH among T1DM patients who are on insulin treatment.

• The discontinuation of rhGH in the setting of T1DM may cause regression of symptomatic T1DM to asymptomatic dysglycemia requiring no insulin treatment.

Summary

A 44-year-old athletic man presented in 2009 with severe low back pain. Dual-energy x-ray absorptiometry revealed severe osteoporosis; serum testosterone was 189 ng/dL while serum estradiol (E₂) measured by liquid chromatography/mass spectrometry was 8 pg/mL. DNA was extracted and sequenced from a blood sample from the patient since his maternal first cousin also had low bone mass and both patients were screened for aromatase dysfunction by PCR analysis for the CYP19A1 gene, which encodes aromatase. No known pathologic mutations were observed in the coding exons, but novel single nucleotide polymorphisms were detected both in the proband and in his cousin. Treatment with topical testosterone started in August 2010. Over the next 8 years, testosterone dosage was varied and switched from topical gel to injections and maintained on depo-injections of testosterone at about 60 mg once per week. Re-examination in March 2012 included a brain MRI to exclude pituitary lesions; hyperparathyroidism was ruled out (normal serum parathyroid hormone, calcium, and calcium to phosphorous ratio) and celiac disease was excluded (negative transglutaminase antibodies). Follow-up in October 2018 showed improved bone mineral density of the lumbar spine by 29% and of the left femoral hip by 15% compared to baseline measurements. This reveals the importance of measuring serum E₂ for making the correct diagnosis, as well as for monitoring a therapeutic effect. Herein, we propose treatment of male osteoporosis where serum E₂ levels are below about 20 pg/mL with testosterone to reverse osteoporosis.

Learning points

• Estrogen deficiency in the diagnosis of male idiopathic osteoporosis.

• Importance of serum estradiol in male osteoporosis.

• Role of polymorphisms in aromatase gene on bone health.

• Reversal of osteoporosis.

• Tailored testosterone treatment for bone health.