Detection of ectopic thyroid remnants: a serious diagnostic dilemma. When molecular biology and immunohistochemistry can solve the problem

Rare Coexistence of Aldosterone-producing Adrenocortical Adenoma Confirmed by an Immunohistochemical Analysis of Steroidogenic Enzymes with Adrenal Ectopic Thyroid Tissue: A Case Report and Literature Review

A 56-year-old man presented with a history of hypertension; clinically, the patient had primary aldosteronism (PA) and a 4-cm left adrenal tumor. The left adrenal glands, resected by adrenalectomy, also contained ectopic thyroid tissue (ETT). An immunohistochemical analysis of steroid-converting enzymes revealed an aldosterone-producing adenoma (APA). Among 19 previously reported cases of adrenal ETT, 4 had adrenal hormonal abnormalities, all of which were PA. This is the first case of adrenal ETT coexisting with APA, confirmed by steroid-converting enzyme expression. Further analyses using cumulative case data are required to clarify the correlation between adrenal ETT and APA.

Ectopic thyroid tissue in adrenal gland, case report and review of literature

Ectopic thyroid tissue is a rare pathological finding bellow the diaphragm and extremely rare finding is ectopic thyroid tissue in the adrenal gland (ETTAG). Thyroid tissue can be located anywhere along the way of embryological migration pathway of thyroglossal duct. In most cases of ectopic thyroid tissue, it is located in the neck. Here we present a case of 29 years old patient that was laparoscopically operated because of adrenal incidentaloma which showed 28 mm in maximal diameter on MRI. The patient had normal adrenal function. Pathohistological finding confirmed ETTAG. Follicular cells express TTF-1, Thyroglobulin, PAX8, and cytokeratin 7, and lack expression of calretinin. This is the 15th such case described in literature. Women are much more affected than men (14:1), and it usually presents in the fifth decade (mean age 49). In all cases ETTAG was composed of normal follicular cells, and C cells were not found. Review of the literature reveals that adrenal ectopic thyroid tissue is almost always cystic, and has distinctive pathologic features. The most important thing is that ETTAG must be distinguished from metastatic deposits from thyroid gland carcinoma. Our patient had normal thyroid function, without any nodules in thyroid gland. We report the youngest patient with ectopic thyroid tissue located in the adrenal gland.

Incidence of ectopic thyroid tissue in the adrenal gland

Ectopic thyroid tissue is a rare pathological finding bellow the diaphragm and extremely rare finding is ectopic thyroid tissue in the adrenal gland. Thyroid tissue can be located anywhere along the way of embryological migration pathway of thyroglossal duct. In most cases of ectopic thyroid tissue, it is located in the neck. Pathohistologically ectopic thyroid tissue in all cases was formed of follicular cells that expressed TTF-1, Thyroglobulin, PAX8, and cytokeratin 7, and there was lack expression of calretinin. In the literature we found 15 such cases. Women are much more affected than men (14:1), and it usually presents in the fifth decade (mean age 49). In all cases it was composed of normal follicular cells, and C cells were not found. Review of the literature reveals that adrenal ectopic thyroid tissue is almost always cystic, and has distinctive pathologic features. The most important thing is that ectopic thyroid tissue must be distinguished from metastatic deposits from thyroid gland carcinoma.

Ectopic thyroid in the gallbladder accompanied with gallbladder adenoma: A case report

RATIONALE

Ectopic thyroid is most common in the tongue. Here we reported a rare case of thyroid tissue located in the gallbladder wall, accompanied with adenoma and a cyst lined with pseudostratified ciliated columnar epithelium in the neck region of gallbladder neck.

PATIENT CONCERNS

A 39-year-old female presented with recurrent upper abdominal pain and radiating back pain.

DIAGNOSES

Based on ultrasonography, gallbladder polyps and calculous cholecystitis were suspected.

INTERVENTIONS

The patient was treated by laparoscopic cholecystectomy, and thyroid tissue located in the gallbladder wall was found. Histopathological examination showed no features of papillary thyroid neoplasm.

OUTCOMES

The patient had no thyroid nodules or suspicious enlarged lymph nodes, and no other symptoms or complications by follow-up for 2.5 years up to September 2019.

LESSONS

We should pay attention to the rare location of ectopic thyroid tissue in the gallbladder and rule out primary thyroid malignancy to avoid unnecessary overtreatment.

Hürthle Cells Adenoma of the Thyroid with Post-surgical Implants in the Neck: Clinical, Morphological, and Molecular Analysis of Three Cases

Thyroid implants in the soft tissue of the neck are very rare findings of traumatic, iatrogenic, or neoplastic origins. We describe the clinico-pathological and molecular analysis of three cases with an initial diagnosis of follicular adenoma, Hürthle cell variant (FA-HCT), which developed cervical thyroid implants at 60, 59, and 36 months after thyroid surgery, followed by further neck recurrences, and, eventually, by distant metastases. A systematic review of all histopathological samples of both the primary lesions and the neck implants was performed. Molecular study included the analysis of pan-RAS and BRAF mutations and RET/PTC1, RET/PTC3, and PAX8/PPARγ rearrangements. The review of the original slides and of additional re-cuts of each block of the thyroid lesions did not show any sign of capsular and/or vascular invasion; thus, the original diagnoses of FA-HCT were confirmed. When sampling adequacy was considered, it turned out that the capsule was completely evaluable in case #3, whereas 85 % was evaluable for case #1 and less than 50 % for case #2. We cannot exclude that cases #1 and #2 were carcinomas that had not been completely sampled. The first occurring neck implants showed neither histological signs of malignancy nor the presence of lymphoid tissue. However, further neck recurrences had different histological aspects, with a clear infiltrative growth. Moreover, a mesenchymal reaction forming a sort of capsule was observed around oncocytic cells along with signs of vascular invasion. Molecular analysis revealed no alterations in the genes and rearrangements studied. Oncocytic thyroid implants in the neck soft tissue should be regarded as metastasis, even in the absence of clear-cut signs of malignancy and in the case of a bona fide diagnosis of Hürthle cells adenoma of the thyroid.

Thyroglossal duct cyst cancer most likely arises from a thyroid gland remnant

Thyroglossal duct cancer is a rare entity, occurring in 1.5 % of all thyroglossal duct cysts (TDC). A definitive consensus about its neoplastic origin has not been established as two contrasting theories exist, one proposing an origin in extra-thyroid remnants and the other a metastatic localization of a primary thyroid cancer. We compare morphological and molecular characteristics of both thyroglossal and thyroid carcinomas in a case series from our institute. We evaluated histology of 80 TDC. In 12 cases, prior cytological evaluation had been performed by liquid-based cytology (LBC). The BRAF gene was examined for mutations, and the histology of both thyroglossal duct and synchronous thyroid carcinoma was reevaluated. In 9 out of 80 (11 %) TDC cases, a papillary thyroid cancer (PTC) was diagnosed. In five out of nine (56 %) thyroglossal carcinomas, a synchronous thyroid cancer was diagnosed: 3 PTC and 2 follicular variant PTC (FVPC). In five thyroglossal carcinomas, mutated BRAF (V600E) was found, three in PTC and in thyroglossal as well as in the synchronous tumor in the thyroid. All the patients are in a disease-free status and still alive. Our results suggest that the majority of thyroglossal carcinomas most likely develop as a primary malignancy from a thyroid remnant. Neither the presence of V600E BRAF mutations nor that of a well-differentiated thyroid carcinoma changed the outcome or disease-free survival. We suggest that a diagnosis of thyroglossal carcinoma should be followed by a detailed evaluation of the thyroid gland. In the absence of clinical and radiological thyroid alterations, follow-up as for thyroid cancer is the correct management.