Amyloid goiter in cystic fibrosis

Diagnosis and management of treatment-refractory hypothyroidism: an expert consensus report

There is a frequently encountered subset of hypothyroid patients who are refractory to standard thyroid hormone replacement treatment and require unexpectedly high doses of levothyroxine. In addition to clinical situations where hypothyroid patients are non-compliant, or where there is the possibility of excipient-induced disease exacerbation (gluten/celiac disease), therapeutic failure may be due to impaired absorption of the administered drug. The common approach to managing patients with unusual thyroxine needs is to escalate the dose of levothyroxine until targeted TSH levels are achieved. This approach can increase the risk for prolonged exposure to supratherapeutic doses of levothyroxine, which increase the chances of adverse outcomes. Repeated adjustments of levothyroxine can also escalate the costs of treatment, as frequent office visits and laboratory tests are required to determine and maintain the desired dose. Clinicians should take a systematic approach to managing patients whom they suspect of having treatment-refractory hypothyroidism. This may include searching for, and adjusting, occult medical conditions and/or other factors that may affect the absorption of levothyroxine, before up-titrating the dose of traditional levothyroxine therapy. Depending on the underlying pathology, another approach that may be considered is to try alternative formulations of levothyroxine that are less susceptible to intolerance issues related to excipients, or, in some cases, to malabsorption. The early discovery of these factors via a thoughtful patient work-up may avoid unnecessary thyroid medication adjustments and their consequences for both patients and clinicians.

When thyroid hormone replacement is ineffective?

PURPOSE OF REVIEW

In this article, we will consider the failure of thyroid hormone replacement therapy to normalize serum thyroid stimulating hormone concentrations. We will review circumstances and causes for failures, discuss pertinent unpublished personal cases of didactical value, and provide practical suggestions for providers encountering patients with similar presentations.

RECENT FINDINGS

Recent data are available on the benefit of novel formulations of levothyroxine therapy on malabsorption.

SUMMARY

Most frequently, reasons for ineffectiveness are noncompliance, inappropriate administration of levothyroxine, gastrointestinal disorders, and drug interactions. The diagnostic work-up should include careful history to elucidate the potential reasons for the ineffective therapy.

Amyloid goiter as a manifestation of primary systemic amyloidosis

Primary amyloidosis involving the thyroid gland is rare and limited to case reports. We report the case of a previously healthy 47-year-old female presenting with a 1-month history of nausea, vomiting, and diffuse thyroid enlargement. Over the next 3 months, she simultaneously developed renal insufficiency dysphagia and hoarseness of voice. Biopsies from the gastric antrum, duodenum, bone marrow, and kidney were positive for vascular deposition of amyloid. Ultrasound of the thyroid revealed diffuse enlargement of the thyroid gland, which was 32.8 ML in volume, with diffuse hyperechogenicity. Fine needle aspiration (FNA) biopsy was positive for amyloid by Congo red staining, and cytology was negative for malignancy. The patient was treated with dexamethasone 40 mg daily on days 1-4, 9-12, and 17-20 for 3 months. On 3-month follow-up, the patient's nausea and vomiting had resolved and renal insufficiency improved. Ultrasound of the thyroid demonstrated decrease in the size of the goiter to 23.2 ML. Amyloid goiter is seen only in approximately 0.04% of patients with primary systemic amyloidosis. No data is currently available regarding treatment of primary amyloidosis and its effect on the goiter. However, we have evidence demonstrating that successful treatment of amyloidosis decreases thyroid enlargement and improves organ dysfunction.

Amyloidosis in cystic fibrosis: A case series

As the life expectancy of patients with cystic fibrosis increases, unusual complications including amyloidosis are increasingly recognised. We report three cases of amyloidosis including a unique case presenting with a hemorrhagic and thrombotic diatheisis. This complication of amyloidosis has never been reported in cystic fibrosis.

Amyloid goiter: report of two cases and review of the literature

OBJECTIVE

To describe two recent cases of amyloid goiter that occurred in two patients with a history of diffuse enlargement of the thyroid gland, progressing over several years' time.

METHODS

We reviewed the medical histories as well as the histologic, immunohistochemical, and electron microscopic findings in these patients.

RESULTS

Assessment of the clinical records of a 59-year-old man and a 64-year-old woman revealed histories that included chronic psoriasiform arthritis and asthma in conjunction with chronic obstructive pneumonia and bronchiectasis. In both cases, total thyroidectomy was performed. On histologic examination of both thyroid glands, the appearance was characterized by moderate to severe distortion of the normal thyroid architecture by amyloid in a perifollicular distribution and focally abundant interfollicular adipose tissue. In both cases, the amyloid stained intensely positive with Congo red, which bleached after treatment with potassium permanganate. Immunohistochemical staining patterns were consistent with AA amyloid, and electron microscopy showed nonbranching 9-nm fibrils consistent with amyloid.

CONCLUSION

The diagnosis of amyloid goiter should be suspected in patients with a diffusely enlarging thyroid gland and an appropriate clinical history.

Amyloid goiter due to primary systemic amyloidosis: a diagnostic challenge

We describe a euthyroid patient who presented with a goiter that continued to enlarge despite levothyroxine administration. Three fine-needle aspirations for cytology were nondiagnostic. An open biopsy was complicated by bleeding from the surgical site. Primary systemic amyloidosis was diagnosed on the basis of the goiter histology, bone marrow aspirate, and urine immunoelectrophoresis. The patient received melphalan and steroid treatment and survived for an additional 16 months. This period was complicated by congestive heart failure, generalized seizures, and upper gastrointestinal bleeding. Our case illustrates the difficulties in making the diagnosis and in treatment of primary systemic amyloidosis.