{
  "abstract": "Background: Thyroid nodules are highly prevalent in the general population, yet their diagnostic assessment may require accurate differential diagnosis in patients with hematologic malignancies. In this context, immune dysregulation, prior cytotoxic therapies, and the potential for atypical extramedullary involvement may confound conventional risk stratification algorithms. Although ultrasonography remains the first-line imaging modality, fine-needle aspiration with ancillary studies is often required for definitive characterization.\n\nCase report: A 47-year-old woman with relapsed multiple myeloma, previously treated with multiagent chemotherapy, radiotherapy, and autologous stem cell transplantation, was evaluated for biochemical and clinical disease progression. Bone marrow biopsy demonstrated no evidence of plasma cell infiltration. However, 18F-fluorodeoxyglucose positron emission tomography/computed tomography identified focal hypermetabolic uptake in the right thyroid lobe. Dedicated neck ultrasonography revealed a 26-mm solid, markedly hypoechoic nodule with peri-nodular vascularity and without definitive sonographic features of papillary thyroid cancer. Given the discordance between imaging findings and marrow status, ultrasound-guided fine-needle aspiration was performed. Cytologic evaluation demonstrated numerous atypical plasma cells, and immunocytochemistry confirmed lambda light chain restriction, consistent with clonal plasma cell proliferation. These findings established intrathyroidal involvement by multiple myeloma, representing an isolated extramedullary relapse in the absence of bone marrow disease.\n\nDiscussion: Intrathyroidal manifestation of multiple myeloma is rare but clinically significant. In patients with systemic malignancies, fluorodeoxyglucose-avid thyroid nodules should prompt consideration of secondary involvement, even when bone marrow evaluation is negative. Conventional ultrasound-based risk stratification systems are primarily designed to detect epithelial thyroid malignancies and may fail to identify nonepithelial neoplasms. Cytologic assessment supplemented by immunophenotypic analysis remains essential for accurate diagnosis.\n\nConclusion: This case highlights the importance of integrating clinical history, functional imaging, cytopathology, and immunocytochemistry to avoid diagnostic pitfalls and to guide appropriate oncologic management.",
  "abstract_shown": true,
  "affiliations": [
    "Interdisciplinary Department of Medicine, School of Medicine, University of Bari Aldo Moro, Bari, Italy",
    "Section of Molecular Pathology, Department of Precision and Regenerative Medicine and Ionian Area (DiMePRe-J), University of Bari Aldo Moro Bari, Italy"
  ],
  "article_type": "case report",
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Domenico Triggiani"
    },
    {
      "affs": [
        0
      ],
      "name": "Giuseppe Lisco"
    },
    {
      "affs": [
        1
      ],
      "name": "Giuseppina Renzulli"
    },
    {
      "affs": [
        1
      ],
      "name": "Mario Della Mura"
    },
    {
      "affs": [
        0
      ],
      "name": "Vincenzo Triggiani"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/c0ma8e7912s06.bib",
  "cited_by": 0,
  "doi": "10.1016/j.aed.2026.06.011",
  "fulltext_url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC13728306/",
  "id": "c0ma8e7912s06",
  "issns": [
    "3050-9157"
  ],
  "landing_url": "https://doi.org/10.1016/j.aed.2026.06.011",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "heading",
      "Case Report"
    ],
    [
      "openalex",
      "2720|Multiple Myeloma Research and Treatments"
    ]
  ],
  "openalex": "W7166888573",
  "pdf_url": "https://www.endocrinologydiabetes.org/article/S3050-9157(26)00140-2/pdf",
  "pmcid": "PMC13728306",
  "pmid": "42978806",
  "published": "2026-07-01",
  "publisher": "American Association of Clinical Endocrinology",
  "ris": "https://research.draconitic.com/paper/c0ma8e7912s06.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T12:24:01Z",
      "native_id": "PMC13728306",
      "source": "pmc",
      "url": "https://doi.org/10.1016/j.aed.2026.06.011"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "journal-openalex:2712|Thyroid Disorders and Treatments",
      "subfield": "endocrinology-metabolism"
    }
  ],
  "title": "Intrathyroidal Relapse of Multiple Myeloma Mimicking Primary Thyroid Neoplasia: A Case Report and Literature Review",
  "title_text": "Intrathyroidal Relapse of Multiple Myeloma Mimicking Primary Thyroid Neoplasia: A Case Report and Literature Review",
  "type": "peer-reviewed",
  "updated_at": "2026-11-07T12:21:19Z",
  "url": "https://research.draconitic.com/paper/c0ma8e7912s06",
  "venue": "AACE Endocrinology and Diabetes",
  "versions": []
}