Skin nontumor
General
Grossing
Author: Cecilia Rosales, M.D.
Last author update: 1 August 2010
Last staff update: 30 May 2020
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: Grossing
Cite this page: Rosales C. Grossing. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skinnontumorgrossing.html. Accessed March 24th, 2023.
Biopsy
- If possible, biopsy a primary lesion
- Proper selection of anatomical site and best lesion to perform a biopsy are very important (An Bras Dermatol 2009;84:507)
- Biopsy characteristic areas in their diagnostic stage, not ruptured bullae, secondarily infected / scratched areas or involuting lesions
- Some lesions are best diagnosed early (blisters, vasculitis) or late (psoriasis, discoid lupus erythematosus, lichen planus)
- Punch biopsy of nearby normal skin may be helpful, particularly if changes in abnormal areas are quantitative (hyperkeratosis, acanthosis, etc.)
- Must recognize that biopsy captures histopathology only at one point in time in evolution of a lesion
- For inflammatory lesions, biopsy should correlate with clinical differential diagnosis
- For widespread dermatoses, avoid biopsying lesions on the legs; at this site but not elsewhere, the biopsy heals slowly and lesions are often hemorrhagic
- For alopecias, biopsy the border of active lesions but if evaluation for hair regrowth is needed, biopsy the most advanced area
- For metabolic abnormalities, electron microscopy of axillary skin biopsy may be helpful, although results may be nonspecific (Hum Pathol 2001;32:649)
Grossing
- Breadloafing (serial section) of ellipses is often best cut perpendicular to long axis at 3 mm intervals
- Always ink margins for tumors, including deep margin
- Bisect punch biopsies if 4 mm or larger
- Biopsy for alopecia: can be cut perpendicular or horizontal depending of the pathology
- Tzanck preparation (smear):
- Used to identify Tzanck (multinucleated) cells of herpes simplex, Varicella and herpes zoster, pemphigus vulgaris or cytomegalovirus
- Scrape the base of the blister / ulcer with the round base of the scalpel
- Smear on a glass slide
- Air-dry and stain with Wright's or Giemsa stains
- Scabies (scrapping):
- Place a drop of immersion oil on a microscope slide
- Place a drop of immersion oil on the scalpel
- Scrape the stratum corneum off the surface of the lesion
- Numerous lesions should be scraped and placed on the same microscope slide
- Submit fresh tissue for:
- Immunofluorescence (can also use Michels medium)
- Bacterial, fungal, and viral cultures
- Chromosomal analysis
- Antigen mapping of basement membrane zone / BMZ (saline splitting)
