A Case of simultaneous occurrence of Marine - Lenhart syndrome and a papillary thyroid microcarcinoma

Abstract

Background: Marine-Lenhart syndrome is defined as the co-occurrence of Graves' disease and functional nodules. The vast majority of autonomous adenomas are benign, whereas functional thyroid carcinomas are considered to be rare. Here, we describe a case of simultaneous occurrence of Marine-Lenhart syndrome and a papillary microcarcinoma embedded in a functional nodule.

Case presentation: A 55 year-old, caucasian man presented with overt hyperthyroidism (thyrotropin (TSH) <0.01 μIU/L; free thyroxine (FT4) 3.03 ng/dL), negative thyroid peroxidase and thyroglobulin autoantibodies, but elevated thyroid stimulating hormone receptor antibodies (TSH-RAb 2.6 IU/L). Ultrasound showed a highly vascularized hypoechoic nodule (1.1 × 0.9 × 2 cm) in the right lobe, which projected onto a hot area detected in the 99mtechnetium thyroid nuclear scan. Overall uptake was increased (4.29%), while the left lobe showed lower tracer uptake with no visible background-activity, supporting the notion that both Graves' disease and a toxic adenoma were present. After normal thyroid function was reinstalled with methimazole, the patient underwent thyroidectomy. Histological work up revealed a unifocal papillary microcarcinoma (9 mm, pT1a, R0), positively tested for the BRAF V600E mutation, embedded into the hyperfunctional nodular goiter.

Conclusions: Neither the finding of an autonomously functioning thyroid nodule nor the presence of Graves' disease rule out papillary thyroid carcinoma.

Figure 1

Ultrasound. Thyroid ultrasound transverse (A, B and C) and sagittal view (D and E) of the right and left thyroid lobe showing a diffusely heterogenous gland with a clearly demarcated hypoechoic hypervascularized nodule in an anterior caudal position of the right lobe.

Figure 2

Thyroid Scan. Thyroid nuclear scan, showed an orthotopic, V-shaped thyroid gland with accentuated radiotracer uptake into the right lobe. The uptake within the right lobe was heterogeneous with a focal area of relatively increased tracer accumulation centro-caudally, which projected onto the location of the hypervascularized adenoma, detected in the ultrasound. Background-activitiy was completely missing, which is compatible with Graves’ disease. A small pyramidal lobe is emanating from the right lobe.

Figure 3

Histology. (A, B) H&E histology of papillary thyroid carcinoma, A, characteristic morphology at low power, B Nuclear morphology at high power. (C) Strip Assay demonstrating BRAF V600E mutation: Strip #1 patient, strip #2 negative control, strip #3 positive control; Formalin fixed paraffin embedded sections of carcinoma tissue were evaluated for the BRAF V600E mutation by using the ViennaLab BRAF Strip Assay.