Bone & joints
General
Grossing, frozen section & features to report
Author: Nat Pernick, M.D.
Last author update: 1 June 2005
Last staff update: 10 January 2022
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed search: grossing WITH bone
Cite this page: Pernick N Grossing, frozen section & features to report. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/bonegrossing.html. Accessed June 4th, 2023.
Grossing
- 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 (Hum Pathol 2004;35:1173)
- 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
Fine needle aspiration
- Helpful for identifying metastatic disease (Arch Pathol Lab Med 2001;125:1463), recurrent tumor or unsuspected malignancy
- Not helpful for cartilaginous lesions, cystic lesions or obviously benign lesions that require surgical management (chondromyxoid fibroma, giant cell tumor)
Frozen section
- Useful to document adequacy of tissue
- Allows quicker definitive treatment (if diagnosis can be made)
- Assessment of tumor margins
- Useful to obtain culture for possible infectious lesions
- Useful to differentiate between aseptic and infectious inflammation for implant replacement
Features to report
- Organ
- Site (include laterality if appropriate)
- Procedure
- Tumor diagnosis
- Tumor size (1 dimension is mandatory, 2 - 3 dimensions if possible)
- Histologic grade (low / high grade or I, II, III or IV)
- Chemotherapy response:
- I: no chemotherapy effect
- IIA: some necrosis, more than 50% viable tumor
- IIB: 3% - 50% viable tumor
- III: less than 3% viable tumor but scattered foci present
- IV: no viable tumor noted
- Tumor extent:
- surface only, cortex only, through cortex, into soft tissue, satellite lesions, invades or crosses joint spaces
- Margins:
- Proximal, distal, distance of tumor to closest surgical margin, involvement of neurovascular bundle at margin
- Lymph nodes: number positive, number examined, extracapsular extension, largest nodal metastasis
- Staging
- Results of special studies
- Optional features:
- Name structures with gross involvement of tumor
- Cystic change, hemorrhage, tumor necrosis (in non chemotherapy cases)
- Large or small vessel invasion present / absent / indeterminate
- Reference: Hum Pathol 2004;35:1173
