Bone
Miscellaneous
Grossing

Author: Nat Pernick, M.D. (see Authors page)

Revised: 22 November 2016, last major update June 2005

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed search: grossing WITH bone

Cite this page: Grossing. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/bonegrossing.html. Accessed December 8th, 2016.
Definition / General
  • Orient specimen using identifiable landmarks
  • Measure specimen (each fragment)
  • Note gross characteristics including color (dead bone is yellow tan), localized lesions, sclerotic areas, calcification, cystic changes, necrosis
  • Radiographs or photographs of sliced bone specimens may be helpful (particularly for nidus of osteoid osteoma)
  • Use scalpel tip to tease out fleshy areas (except near tumors) for nondecalcified fixation
  • Histomorphometry may be helpful for metabolic bone disease
  • Submit fresh tissue for ancillary studies, as needed

  • Decalcification:
    • 20% formic acid in 10% formalin (400 ml of formic acid in 1600 ml of 10% formalin)
    • Fix bone first; decalcify slices but not entire specimen in adequate amount of formic acid; change solution (dissolved calcium neutralizes the acid); wash thoroughly to remove acid
    • Small specimens may require only a few hours
    • Check specimen periodically to avoid excessive decalcification

  • Bone biopsy:
    • Divide needle biopsy longitudinally with a fine toothed saw if 5 mm or more in diameter
    • Dissect out soft tissue and process separately without decalcification

  • Open biopsy and curettage:
    • Separated calcified from noncalcified tissue and process separately

  • Femoral head:
    • Hold specimen with a clamp or vice and cut through center of articular surface with band saw
    • Then make another parallel cut 3 mm from the first cut
    • Submit abnormal areas, articular surface and synovium

  • Bone resection for tumor:
    • Review xrays
    • Check prior biopsy sites
    • Identify lymph node groups; dissect and place in separate containers
    • Ink and examine margins (scoop bone marrow from end margin)
    • Dissect away soft tissue, leaving bone and soft tissue extension of tumor (margins of soft tissue are examined at frozen section)
    • Examine major vessels and nerve trunks (limb specimens)
    • Determine position of tumor with respect to other landmarks present
    • Bivalve tumor with band saw (anterior - posterior or what exposes most of the bone tumor)
    • Describe status of cortex near tumor
    • Cut through joint if no apparent tumor
    • If joint contains apparent tumor, make cross section through adjacent noninvolved bone, then open and examine joints
    • Obtain 3 - 4 mm sections of tumor using band saw or handheld saw
    • Wash with running water, brush cut surfaces of bone with a nail brush to remove bone dust
    • Check for satellite lesions (examine under Wood's light if tetracycline was administered)
    • Calculate %necrosis in post chemotherapy specimens
      • For osteosarcoma and Ewing sarcoma, sample completely a slice of the tumor using a grid pattern diagram
      • Take additional blocks perpendicular to previous ones to evaluate tumor in 3 dimensions
      • Examine blocks from soft tissue, tumor / nodal interface, cortex, subcortical marrow, pericartilaginous regions, necrotic areas, ligaments
      • Necrosis is defined as follows:
        • Osteoblastic and chondroblastic osteosarcomas: empty lacunae or ghost cells
        • Fibroblastic and small cell osteosarcomas and Ewing's sarcoma: fibrous and granulation tissue replacing cellular tumor
        • Telangiectatic osteosarcoma: residual cystic spaces with blood or hemosiderin
        • Note: post chemotherapy atypia is NOT considered necrosis

  • Sections to submit:
    • 4 or more sections of tumor (representative, including dissimilar areas; tumor and cortex, medulla, articular cartilage, periosteum, soft tissue, epiphyseal line)
    • Tumor and margin
    • Osseous margin of resection
    • Prior biopsy sites
    • Other abnormal areas
    • Lymph nodes
Additional References