ABSTRACT
Glandular/pseudoglandular pattern 4 Ductal glandular pattern 4 Tubular pattern 5 Acinar/microacinar pattern 6 Papillary and pseudopapillary pattern 6 Cribriform pattern 9 Follicular pattern 9 Adenoid cystic pattern 10 Canalicular pattern 11 Endometrioid pattern 11 Mucinous glandular pattern 11 ‘Signet ring’ glandular pattern 12 Retiform pattern 12 Adenomatoid pattern 13 Microcystic glandular pattern 13 Adenocarcinomas with ‘bull’s eye’-type cells 13 ‘Hobnail’ pattern 15 Glandular structures with squamous change/metaplasia 15 Glandular structures with clear cell change 16 ‘Slit-like’ pattern 16 Pseudoglandular pattern 16
Non-glandular epithelial/epithelioid pattern 17 Basaloid pattern 17 Comedo pattern 18 Alveolar pattern 19 Packeted pattern 19 Palisading pattern 19 Reticular, reticulated or lattice patterns 21 Squamoid pattern 21 Trabecular pattern 21 Scirrhous/desmoplastic pattern 23 Undifferentiated pattern 24 Pseudocystic patterns 25
Round cell pattern 25 Diffuse round cell pattern 25 Septate or lobulated round cell pattern 25 Alveolar/pseudoalveolar round cell pattern 25 Round cell pattern with rosettes 25 Round cell pattern with other component(s) 26 Round cell pattern with hemangiopericytomatous
vascular pattern 27 Round cell pattern with desmoplastic stroma 27 Mixed round cell pattern 28 Large round cell pattern 28
Spindle cell pattern 28 Diffuse monomorphic bland spindle cell pattern
Diffuse monomorphic highly cellular spindle cell pattern (fibrosarcoma pattern) 30
Pleomorphic spindle cell pattern (malignant fibrous histiocytoma pattern) 31
Spindle and epithelioid cell pattern 32 Spindle cell pattern with prominent sclerosis 32 Storiform and whorled pattern 32 Nodular fasciitis pattern 34 Spindle cell pattern with significant inflammatory components 35 Spindle cell pattern with osteoclast-giant cells 37 Spindle cell populations with hemangiopericytomatous pattern 37
Spindle cell admixed with other mesenchymal components 38 Spindle cell lesions with signficiant fatty component 39 Spindle cell lesions with significant myxoid component 39 Spindle cell lesions with significant osteoid component 42 Spindle cell lesions with significant chondroid component 43 Tumors with mixed mesenchymal components 43
Biphasic pattern 43
Vascular pattern 44 Anastomosing/intercommunicating/slit-like vascular channels 44 Granulation tissue-type vessels 44 Hemangiopericytomatous-type vessels 45 Plexiform capillary pattern (‘chicken feet’) 45 Ectatic vessels 46 Papillary vascular pattern 46 Capillary hemangioma pattern 46 Cavernous hemangioma pattern 46 Mixed vessels pattern 47 Epithelioid hemangioma pattern 47 Pseudovascular 47
Prominent non-cellular pattern 48 Amyloid/amyloid-like material 48 Calcification/microcalcification 48 Hyaline bands/strands/nodules/keloid-like hyalinization 49 Hyaline globules 51 Psammoma bodies 51 Crystals 51
Distinctive cell types 52 Anaplastic cells 52 Clear cells 52 Granular cells 52 Oxyphilic/oncocytic/oncocytoid cells 52 Hyalinized/plasmacytoid cells 54 Rhabdoid cells 55 Signet ring cells 56
This section is principally aimed at trainee pathologists who are not yet familiar with the various histological patterns and sub-patterns that may be encountered in the various tumors. It therefore lists 10 main broad histological patterns with their sub-patterns. Each of these patterns is defined and illustrated, and typical and common examples of tumors that exhibit these patterns are also provided.
