A guide to Thyroid Cancer Histopathology Reporting Includes the International Collaboration on Cancer reporting dataset denoted by * Clinical details Microscopic findings cont. S1.02 Clinical info. on request Text S3.03 *Mitotic activity Not identified/ form (complete as narrative OR **Note: 2 mm2 approximates 10 high power low (<3 mitoses/2 2 or use the structured format Information not fields on some microscopes. mm ) below) provided* High (>3 mitoses/2 mm2) *Previous history of Text Can’t be assessed, thyroid tumour or related specify abnormality __ mitotic figures/2 mm2** *Relevant biopsy/ Text cytology results G3.01 *Histological grade Well differentiated Poorly *Imaging findings Text differentiated Undifferentiated/ *Previous surgery/ Text anaplastic therapy S3.04 *Tumour encapsulation/ Encapsulated *Relevant family history Text circumscription Infiltrative Other, specify *Presence of clinical Text S3.05 *Capsular invasion Not applicable syndrome Uncertain Not identified G1.01 Copy to doctor Text Present Can’t be assess’d, S1.03 Pathology accession Text specify number S3.06 *Lymphovascular invasion Can’t be assess’d, S1.04 Principal clinician Text specify Not identified G1.02 Other clinical information Text Present received *Vascular invasion See p2 Macroscopic findings S3.07 *Necrosis Not identified S2.01 Specimen labelled as Text Present S2.02 Text *Clinical information S3.08 *Extrathyroidal extension See p3 S2.03 See p2 *Operative procedure S3.09 *Margin status Not involved Type of partial excision Text Involved, specify (anterior or S2.04 *Operative findings See p2 posterior) Can’t be assess’d, S2.05 Specimen(s) submitted See p2 * specify G2.01 Specimen weight __ g Distance to closest margin __ mm S2.06 Can’t be assess’d, *Tumour focality Margin (anterior or posterior) Text specify Unifocal S3.10 *Lymph node status No nodes Multiple submitted or found *Number of tumours in ___ Not involved specimen Involved S2.07 *Tumour site See p2 *No. of lymph nodes Number can’t be examined determined S2.08 Macroscopic description Text OR __ G2.02 Thyroid appearance Text *No. of positive lymph nodes __ S2.09 Block identification key Text *Location of involved lymph Text G2.03 Other macro. comment Text nodes *Greatest dimension of __ mm Microscopic findings largest lymph node with metastasis S3.01 *Histological tumour See p2 type *Greatest dimension of __ mm largest metastatic focus in S3.02 Microscopic tumour Can’t be assess’d, * lymph node dimension specify OR Max. tumour dimension *Extranodal extension (ENE) Not identified __ mm OR Present (largest tumour) Can’t be Additional dimensions __ mm x __ mm determined (largest tumour) G3.02 *C-cell hyperplasia Not identified Present Unilateral Bilateral V2.0 Guide derived from Thyroid Cancer Structured Reporting Protocol 2nd Edition Page 1 of 3 Microscopic findings cont. S2.05 Specimen(s) submitted S3.11 *Parathyroid gland status Not identified Present (normal, Not specified* involved by OR (Select all that apply) carcioma, • Thyroid gland hypercellular/ o Left enlarged) o Right o Isthmus *No. of parathyroid gland(s) __ • Parathyroid gland(s) S3.12 Not identified *Distant metastases • Lymph node(s), specify site(s) and laterality Not assessed Present, specify • Other, specify site(s) and laterality site(s) S3.13 Coexistent abnormalities See p3 S2.07 Tumour site G3.03 Additional microscopic comment Text Not specified* OR (Select all that apply) Ancillary findings • Lobe o Left G4.01 *Ancillary studies Not performed Performed, o Right specify • Isthmus • Pyramidal lobe Results Text • Soft tissue or muscle, specify site(s) and laterality G4.02 Molecular studies Text • Other, specify site(s) and laterality Synthesis and overview S3.01 Histological tumour type See p3 S5.01 *PATHOLOGICAL STAGING • Papillary thyroid carcinoma S5.02 Year and edition of staging Text o Classic (usual, conventional) o Cribriform-morular variant system o Diffuse sclerosing variant G5.01 Diagnostic summary Text o Encapsulated variant o Encapsulated/well-demarcated follicular variant with invasion Include: Operative procedure; o Infiltrative follicular variant Tumour site; Histological tumour o Hobnail variant type; Tumour stage; Margin o Microcarcinoma status. o Oncocytic variant o Solid variant S5.03 Overarching comment Text o Tall cell variant o Warthin-like variant G5.02 Edition/version of RCPA protocol Text o Other variant, specify • Follicular thyroid carcinoma (FTC) o FTC, minimally invasive o FTC, encapsulated angioinvasive S2.03 Operative procedure o FTC, widely invasive Not specified* • Hürthle (oncocytic) cell tumours OR (Select all that apply) o Hürthle cell carcinoma, minimally invasive o Hürthle cell carcinoma, encapsulated angioinvasive • Total thyroidectomy o Hürthle cell carcinoma, widely invasive • Near total thyroidectomy • Poorly differentiated thyroid carcinoma • Hemithyroidectomy • Anaplastic thyroid carcinoma • Lobectomy • Squamous cell carcinoma • Isthmusectomy • Medullary thyroid carcinoma • Partial excision* • Mixed medullary and follicular thyroid carcinoma • Mucoepidermoid carcinoma • Lymph node dissection • Sclerosing mucoepidermoid carcinoma with eosinophilia • Other, specify • Mucinous carcinoma • Spindle epithelial tumour with thymus-like differentiation *Note: Anything less than a lobectomy excluding isthmusectomy, including • Intrathyroid thymic carcinoma substernal excision. • Other, specify S3.06 Vascular invasion S2.04 Operative findings • Not identified • Not specified* • Present, for encapsulated neoplasms • Intra-operative macroscopic evidence of extrathyroidal extension o Focal, <4 foci o Yes, specify location and tissue invadedt o Extensive, >4 foci o No o Information not available • Extrathyroidal blood vessel invasion o Not identified • Intra-operative impression of completeness of excision o Present o R0/R1 o R2, specify location • Small vessel, not otherwise classifiable o Information not available • Cannot be assessed, specify • Other, specify o Neuroblastoma, specify o Ganglioneuroma, specify o Malignant peripheral nerve sheath tumour, specify • Other, specify V2.0 Guide derived from Thyroid Cancer Structured Reporting Protocol 2nd Edition Page 2 of 3 S3.08 Extrathyroidal extension S5.01 Stage & stage group## • Cannot be assessed Suffixes • Not identified m - multiple primary tumours; y - post therapy; r - recurrent OR (Select all that apply) Primary Tumour (pT) • Invasion into perithyroid fibroadipose tissue TX Primary tumour cannot be assessed • Invasion into skeletal muscle T0 No evidence of primary tumour • Invasion into subcutaneous soft tissue, larynx, trachea, oesophagus or recurrent laryngeal nerve T1 Tumour <2 cm in greatest dimension limited to the thyroid • Invasion into prevertebral fascia or encasing the carotid artery or T1a Tumour <1 cm in greatest dimension limited to the thyroid mediastinal vessel T1b Tumour >1 cm but <2 cm in greatest dimension limited to the thyroid T2 Tumour >2 cm but <4 cm in greatest dimension limited to S3.13 Coexistent pathological the thyroid abnormalities T3 Tumour >4 cm limited to the thyroid, or gross extrathyroidal extension invading only strap muscles None identified T3a Tumour >4 cm limited to the thyroid T3b Gross extrathyroidal extension invading only strap muscles OR (Select all that apply) (sternohyoid, sternothyroid, thyrohoid, or omohyoid • Nodular hyperplasia muscles) from a tumour of any size • Diffuse hyperplasia T4 Includes gross extrathyroidal extension beyond the strap • Dyshormonogenetic goitre muscles • Chronic lymphocytic thyroiditis T4a Gross extrathryroidal extension invading subcutaneous soft • Follicular adenoma tissues, larynx, trachea, oesophagus, recurrent laryngeal nerve from a tumour of any size • Hurthle cell adenoma T4b Gross extrathyroidal extension invading prevertebral fascia • Non-invasive follicular thyroid neoplasm with papillary-like nuclear or encasing the carotid artery or mediastinal vessels from features (NIFTP) a tumour of any size • Other, specify Regional lymph node (pN) NX Regional lymph nodes cannot be assessed N0 No evidence of locoregional lymph node metastasis N0a One or more cytologically or histologically confirmed benign lymph nodes N0b No radiologic or clinical evidence of locoregional lymph node metastasis N1 Metastasis to regional nodes N1a Metastasis to level VI or VII (pretracheal, paratracheal, or prelaryngeal/Delphian, or upper mediastinal) lymph nodes. This can be unilateral or bilateral disease. N1b Metastasis to unilateral, bilateral or contralateral lateral neck lymph nodes (levels I, II, III, IV or V) or retropharyngeal lymph nodes ## Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Eighth Edition (2017) published by Springer Science and Business Media LLC, www.springerlink.com . V2.0 Guide derived from Thyroid Cancer Structured Reporting Protocol 2nd Edition Page 3 of 3.