Patología de la Tiroides: Visión General

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Questions and Answers

¿Qué característica es más común en el carcinoma de tiroides?

Es más frecuente en hombres que en mujeres.

Suele ser una masa dolorosa en el cuello.

Se presenta como un nódulo indoloro. (correct)

Generalmente se asocia con hipertiroidismo.

¿Cuál de las siguientes afirmaciones sobre la epidemiología del carcinoma de tiroides es correcta?

No tiene prevalencia en grupos étnicos específicos.

Es más común en mujeres en edad reproductiva. (correct)

Afecta mayormente a hombres de edad avanzada.

La incidencia es uniforme en todos los grupos de edad.

En un análisis histopatológico del carcinoma de tiroides, ¿qué características microscópicas se suelen observar?

Papilas complejas y ramificadas con núcleos en solapamiento. (correct)

Tejido adiposo en reposo.

Células con citoplasma abundante y oscuro.

Células grandes con núcleos prominentes.

¿Cuál es la diferencia principal entre un adenoma folicular y un carcinoma de tiroides?

Los adenomas foliculares tienen una cápsula y no invaden tejidos adyacentes. Signup and view all the answers

¿Qué porcentaje de carcinomas de tiroides se presenta con metástasis en los nodos linfáticos en el diagnóstico inicial?

14% Signup and view all the answers

¿Cuál es la característica principal de la enfermedad de Graves?

Hipertiroidismo Signup and view all the answers

En la tiroiditis de Hashimoto, ¿qué tipo de células se presentan en infiltración abundante?

Células inflamatorias Signup and view all the answers

¿Qué tipo de anticuerpos está elevado en la tiroiditis de Hashimoto?

Anticuerpos antiperoxidasa tiroidea Signup and view all the answers

¿Qué describe mejor el aspecto macroscópico de un quiste del conducto tirogloso?

Superficie externa redondeada y lisa Signup and view all the answers

¿Cuál es la principal diferencia histológica entre los folículos tiroideos en la tiroiditis de Hashimoto y en la tiroides normal?

Folículos atrofia con Hürthle en Hashimoto Signup and view all the answers

Las células oncocíticas se caracterizan por:

Células grandes con citoplasma eosinofílico Signup and view all the answers

¿Cuál es la prevalencia de la tiroiditis de Hashimoto en mujeres?

90-95% Signup and view all the answers

¿Qué tipo de epitelio se puede encontrar en un quiste del conducto tirogloso?

Todos los anteriores Signup and view all the answers

En un adenoma folicular, ¿qué hallazgo histológico es típico?

Crecimiento de folículos bien definidos Signup and view all the answers

La descripción macroscópica de un bocio multinodular incluye:

Aumento asimétrico del tiroides Signup and view all the answers

¿Cuál de las siguientes características es típica de la enfermedad de Graves?

Presencia de anticuerpos contra el receptor de TSH Signup and view all the answers

¿Cuál es la causa más común de bocio multinodular en el mundo?

Deficiencia de yodo Signup and view all the answers

¿Qué hallazgo microscópico es característico de un adenoma folicular?

Folículos dilatados, pero con cápsula gruesa Signup and view all the answers

¿Cuál de los siguientes es un síntoma asociado comúnmente con la enfermedad de Graves?

Oftalmopatía infiltrativa Signup and view all the answers

En un bocio multinodular, ¿qué describe mejor la clasificación de los nódulos?

Nódulos asimétricos y grandes Signup and view all the answers

¿Cómo se presenta típicamente el carcinoma folicular en un escáner radionúclido?

Nódulo frío Signup and view all the answers

¿Cuál de las siguientes características histológicas no se encuentra en un adenoma folicular?

Invasión de tejido adyacente Signup and view all the answers

¿Qué tipo de carcinoma tiroideo abarca entre el 6-10% de los carcinomas tiroideos?

Carcinoma folicular Signup and view all the answers

¿Cuál de las siguientes patologías suele presentar formación de glóbulos y puede mimetizar un carcinoma por sus proyecciones papilares?

Bocio multinodular Signup and view all the answers

¿Qué característica microscópica es típica en el carcinoma folicular?

Invasión de vasos sanguíneos Signup and view all the answers

¿Qué tipo de cambios secundarios se pueden observar en un adenoma folicular?

Hemorragia y cambios quísticos Signup and view all the answers

¿Cuál es la principal característica del carcinoma de células Hürthle?

Células más de 75% oncocíticas Signup and view all the answers

¿Cuál de las siguientes características diferencia la enfermedad de Hashimoto de la enfermedad de Graves?

Hipotiroidismo vs. hipertiroidismo Signup and view all the answers

¿Qué condición típicamente presenta cambios histológicos como fibroplasia y hemorragia en la tiroides?

Bocio multinodular Signup and view all the answers

Study Notes

Thyroid Pathology: General Overview

Thyroid pathology encompasses a range of diseases affecting the thyroid gland

Thyroid Gland: Anatomy

The thyroid gland is a bilobed organ located in the lower anterior neck
Composed of two lateral lobes connected by an isthmus
The shape of the adult thyroid resembles a butterfly or the capital letter H
Each lobe exhibits a pointed upper pole and a blunted lower pole
Understanding surgical specimen submission (lobectomy, hemithyroidectomy, total thyroidectomy) is crucial for pathologists
Thyroid biopsies, often combined with ultrasound, are frequently performed
Historical context: English name derives from Greek "thyreoeides," German name "Schilddrüse" meaning "shield gland." Leonardo da Vinci is credited with the first anatomical depiction of the thyroid, and Thomas Wharton named it due to its location near the thyroid cartilage.

Pyramidal Lobe

A vestige of the inferior portion of the thyroglossal duct
A small conical projection of thyroid tissue extending from the isthmus upward to the hyoid bone, often positioned on the surface of the thyroid cartilage
Present in approximately half of all thyroid glands
Average length is 24 mm, with some pyramidal lobes exceeding 20 mm
Typically attached to the left side of the isthmus or to the left lobe itself

Thyroid Gland: Histology

Composed of thyroid follicles, each lined by a single layer of cuboidal to low columnar epithelium
The lumen of the follicles usually contains colloid, which can appear scalloped or densely eosinophilic depending on activity levels
Stroma, including C cells (formerly known as parafollicular cells), are also present
C cells produce calcitonin

Thyroid Gland: Physiology

The regulation of thyroid hormones (T3 and T4) is a complex process involving the hypothalamus and pituitary gland
The hypothalamus releases TRH (thyrotropin-releasing hormone), which stimulates the anterior pituitary to synthesize and release TSH (thyroid-stimulating hormone)
TSH in turn stimulates the thyroid gland to produce T3 and T4
T3 and T4 exert a negative feedback loop on the hypothalamus and pituitary, regulating their respective secretions

Sanderson's Polsters

Collections of small follicles projecting into the lumen of larger follicles
Can mimic papillary carcinoma

Oncocytes (Hürthle Cells)

Large cells characterized by abundant, deeply eosinophilic cytoplasm and numerous mitochondria.

Positive Stains

Follicular cells stain positively for thyroglobulin, TTF1, and low molecular weight keratin.
Colloid stains positively for thyroglobulin.
C cells stain positively for calcitonin, neuron-specific enolase, chromogranin A, and synaptophysin.

Thyroglossal Duct Cyst (TGD)

Congenital anomaly of the thyroid gland
The most common congenital neck mass
Due to the persistence and cystic dilation of the thyroglossal duct.
External surfaces are usually smooth and rounded.
Contents can range from clear mucus to viscous gel, varying in color (clear, yellowish tan, reddish brown, and grayish white). Infected cysts may contain pus.
Histologically, lining can vary: Ciliated pseudostratified columnar (respiratory), squamous, or cuboidal epithelium. Cysts often lack epithelium in some areas, reflecting inflammation. Thyroid follicles may be present in cyst or duct wall.

Hashimoto's Thyroiditis

An autoimmune disease characterized by inflammation of the thyroid gland
Predominantly affects women (90-95%) typically between the ages of 45 and 65, with familial clustering.
More frequent in white individuals compared to black individuals.
Often characterized by a painless, gradual onset of impaired thyroid function (hypothyroidism).
Frequently results in an enlarged thyroid gland (goiter), though not always.

Graves' Disease ("Basedow Disease")

An autoimmune disorder leading to hyperthyroidism
Named after Robert J. Graves
Commonly affects middle-aged women
Characterized by increased thyroid hormone production
Associated with symptoms such as diffuse goiter, infiltrative ophthalmopathy, and, less frequently, infiltrative dermopathy.

Multinodular Goiter

The most common thyroid disease
Characterized by an enlarged thyroid gland with multiple nodules
Nodular enlargement with distorted outer surfaces
Can cause compression of the trachea, esophagus, or blood vessels
Frequently asymptomatic and euthyroid.
Iodine deficiency is the most common worldwide cause.
Serum thyroid-stimulating hormone (TSH) decreases with increasing goiter size as TSH is negatively correlated with the size of the goiter

Follicular Adenoma

A benign tumor of the thyroid gland
Often presents as a solitary "cold" nodule.
Usually encapsulated, but size variations exist (1-10 cm)
Solid, fleshy, and tan to light brown in appearance

Follicular Carcinoma

A malignant tumor of the thyroid gland, comprising 6-10% of thyroid carcinomas
Usually a solitary 'cold' nodule, warranting extensive sampling of the capsule.
Three subtypes distinguished by invasiveness: minimally invasive, capsular invasion only, and widely invasive
Grossly, shows solid, tan-brown solid cut surface, possible cystic changes, and hemorrhage

Oncocytic (Hürthle Cell) Tumors

A type of follicular neoplasm characterized by the presence of a significant proportion of oncocytes (Hürthle cells)
Oncocytes are characterized by abundant, granular eosinophilic cytoplasm and prominent mitochondria in high numbers.
Malignant if the tumor demonstrates capsular and vascular invasion

Papillary Carcinoma

The most common thyroid malignancy in adults (75-80%)
Frequently presents as a painless nodule or mass in the neck.
Frequently, diagnosed by FNA
Often associated with occult tumors at autopsy (1 to 10 mm). Can be multicentric (46%) or exhibit nodal metastases (14%).

Psammoma Bodies

Mineral-containing calcifications frequently observed within the fibrous stroma between papillary tumor cells
Commonly found in papillary thyroid carcinoma.

Medullary Carcinoma

A neuroendocrine tumor derived from C cells (formerly called parafollicular cells) in the thyroid.
Either sporadic (nonhereditary) or familial (hereditary)
Sporadic cases may result in a single tumor, whereas familial cases are more commonly bilateral
May have bilateral, multicentric growth
Frequently diagnosed via screening tests for calcitonin or for RET oncogene mutations
Frequently identified by an analysis of serum calcitonin levels
Usually a single circumscribed, non-encapsulated, gray-tan mass
Variety of morphologies may resemble other thyroid malignancies.

Secondary Tumours/Metastases

These tumors arise from other sites and spread to the thyroid through direct extension or via blood vessels
Not a common finding
Most often detected in individuals with known, pre-existing malignancies

Poorly Differentiated Thyroid Carcinoma

Anaplastic Carcinoma

A highly aggressive, undifferentiated thyroid cancer
Rare, accounting for a small percentage (2-5%) of thyroid cancers but contributing approximately 40% of cancer-related deaths
Rapidly enlarging, bulky neck mass

Classification of Thyroid Carcinoma

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Description

Este cuestionario ofrece una visión general de la patología tiroides, incluyendo su anatomía y las características del órgano. Explora aspectos como la lobectomía y la importancia de las biopsias en el diagnóstico, además de su contexto histórico. Ideal para aquellos interesados en la anatomía y enfermedades de la glándula tiroides.