Endocrine Pathology, Pathology, USMLE Step 1 - Full Vignette with Extended Explanations скачать в хорошем качестве

Endocrine Pathology, Pathology, USMLE Step 1 - Full Vignette with Extended Explanations

In a tertiary endocrine clinic, four patients with thyroid nodules undergo ultrasound, cytology or histology, and other systematic investigations. Each presents with distinct clinical features, laboratory findings, and imaging results. How do you determine which patient's pathological and biochemical profile indicates a calcitonin-driven disease requiring further genetic and endocrine evaluation before surgical intervention? What clues in the workup guide your differential diagnosis for hereditary endocrine syndromes? VIDEO INFO Category: Endocrine Pathology, Pathology, USMLE Step 1 Difficulty: Hard - Advanced level - Challenges experienced practitioners Question Type: Pathology Case Type: Multi Patient Explore more ways to learn on this and other topics by going to https://endlessmedical.academy/auth?h... QUESTION Four patients are seen in a tertiary endocrine clinic on the same day. All have recent ultrasound of the thyroid and cytology or histology, along with other investigations submitted by referring clinicians.... OPTIONS A. The patient whose thyroid core biopsy shows nests of polygonal cells in an amyloid-rich stroma with Congo red birefringence and strong calcitonin immunostaining, consistent with medullary thyroid carcinoma and necessitating RET germline testing and MEN2 evaluation before any thyroid surgery. B. The patient whose fine-needle aspirate shows papillary fronds with fibrovascular cores, nuclear grooves, and optically clear Orphan Annie eye nuclei with psammoma bodies, compatible with papillary thyroid carcinoma that typically expresses thyroglobulin and TTF-1 rather than calcitonin. BRAF V6... C. The patient whose lobulated encapsulated nodule exhibits microinvasion of capsule and vasculature on histology with uniformly low calcitonin levels, indicating minimally invasive follicular thyroid carcinoma prone to hematogenous spread rather than amyloid deposition. D. The patient with a hypercellular oxyphilic (Hu rthle-cell) neoplasm showing abundant granular eosinophilic cytoplasm and mitochondria-rich oncocytic change, lacking amyloid and calcitonin staining, more often associated with chronic lymphocytic thyroiditis than with MEN2 syndromes. CORRECT ANSWER A. The patient whose thyroid core biopsy shows nests of polygonal cells in an amyloid-rich stroma with Congo red birefringence and strong calcitonin immunostaining, consistent with medullary thyroid carcinoma and necessitating RET germline testing and MEN2 evaluation before any thyroid surgery. EXPLANATION Calcitonin-producing thyroid malignancy with amyloid-rich stroma is medullary thyroid carcinoma (MTC), which mandates RET germline testing and MEN2 evaluation before thyroid surgery. Patient A s core biopsy shows nests of polygonal cells in an amyloid-rich stroma with Congo red birefringence and strong calcitonin and CEA immunostaining; serum calcitonin is markedly elevated. These features are diagnostic of MTC and trigger MEN2 work-up and perioperative catecholamine screening. Patient B s cytology shows papillary fronds with fibrovascular cores, nuclear grooves, optically clear Orphan Annie nuclei, and psammoma bodies with thyroglobulin and TTF-1 positivity-classic papillary thyroid carcinoma (PTC), a thyroglobulin-secreting tumor, not calcitonin-driven. Patient C s encapsulated follicular-patterned tumor with capsular and vascular microinvasion and low calcitonin fits minimally invasive follicular thyroid carcinoma.... Further reading: Links to sources are provided for optional further reading only. The questions and explanations are independently authored and do not reproduce or adapt any specific third-party text or content. --------------------------------------------------- Our cases and questions come from the https://EndlessMedical.Academy quiz engine - multi-model platform. Each question and explanation is forged by consensus between multiple top AI models (i.e. Open AI GPT, Claude, Grok, etc.), with automated web searches for the latest research and verified references. Calculations (e.g. eGFR, dosages) are checked via code execution to eliminate errors, and all references are reviewed by several AIs to minimize hallucinations. Important note: This material is entirely AI-generated and has not been verified by human experts; despite stringent consensus checks, perfect accuracy cannot be guaranteed. Exercise caution - always corroborate the content with trusted references or qualified professionals, and never apply information from this content to patient care or clinical decisions without independent verification. Clinicians already rely on AI and online tools - myself included - so treat this content as an additional focused aid, not a replacement for proper medical education. Visit https://endlessmedical.academy for more AI-supported resources and cases. This material can not be treated as medical advice. May contain errors. ---------------------------------------------------