Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
 Home | Pathology Group Members | Our Hospital |  Search This Website:
        Skin adnexal & odd malignancies
      
FUNDAMENTAL TRUISMS: Adnexal carcinomas (adenocarcinomas): (1) tend to not show a demonstrable connection to the epidermis (& no overlying epidermal PMK) and be centered in dermis, and (2) tend toward increased risk for regional...even distant...metastases. So, be certain of "wide and deep" margins (as with melanoma)...maybe even sentinel node biopsy for the worst ones. Watch out for perineural space neurotropism & potential need for radiation therapy or wider re-excision if present. All cutaneous malignancies unlikely to have a benign (symetrical, top heavy, wedge shaped) cross-sectional sihouette microscopically. It is sometimes problematic in distinguishing benign adnexal proliferations from malignant. Fewer than 1/1000 skin malignancies are adnexal. [(1) IHC DDX table.....(2) old IHC outline (some markers we don't have)]
  • Sweat gland malignancies:
    • eccrine: (S100 pos2; CD107 & K903 negative & can have some NSE positive; may have comedonecrosis & high mitotic rate; intracytoplasmic lumen, by d-PAS, EMA, or CEA positivity may be a positive tip-off to DX8).
      • eccrine ductal adenocarcinoma (carcinoma simplex, anaplastic syringoma, malignant acrospiroma)...they recapitulate ductal breast cancer varieties:
        1. variants:
          • spindle cell variant:
          • basaloid variant: cells tend to have nucleoli
          • squamous metaplastic variant:
          • variant with abundant fibromyxoid stroma:
        2. behavior2: about 50% metastasize to regional and/or organs; 70-80% locally recur & can have years of delay prior to recurrence or mets2. [S-04-4027; LMC-04-10771]
      • eccrine porocarcinoma: 30% mets to other skin sites, nodes and/or viscera
        1. invasive: [poroma vs. porocarcinoma, S-04-11320]
        2. intraepidermal porocarcinoma (malignant hidroacanthoma simplex)
        3. behavior2: about same as eccrine ductal, above EXCEPT epidermotrophic mets to other skin sites.
      • mucinous eccrine ca.: "colloid ca."; node mets rare; behavior2 is low grade & few mets & OK with conservative, clear resection.
      • clear cell eccrine hidradenocarcinoma: rare; behavior2 potential somewhere between above ductal & mucinous.
      • adenoid cystic eccrine ca.: rare; (if in ear canal are "ceruminomas"); perineural invasion (neurotropism); behavior2 can met. but wide local excision OK [S-04-6168].
      • [aggressive] papillary digital eccrine ca.: tends to get into underlying bone & locally recurr & late mets: wide local excision/amputation.
      • microcystic adnexal ca. (MAC..."sclerosing sweat duct ca.", see below): very locally but slowly aggressive with 50% recurrence despite wide & controlled excision! (features superficial keratinizing microcysts, deep luminal structures...zonation5...and neurotropism3). Ki67 less than 5%6.[S-05-10101] DDX5: syringoma and desmoplastic trichoepithelioma [p53 negative]  (infiltrative pattern and neurotropism in MAC); zonation & lumens in MAC & not morpheaform BCC; keratocysts in MAC & not syringomatous carcinoma, eccrine epithelioma.
      • sclerosing sweat duct ca. (syringoid ca.): related to microcystic adnexal ca.[S-03-45693]
      • carcinoma ex eccrine spiradenoma: small % with mets; disorganized like eccrine ductal.
      • carcinoma ex eccrine cylindroma: high % with mets; disorganized like eccrine ductal.
      • malignant mixed tumor: overt nuclear atypia & abundant mitoses; signif. node & visceral mets.
      • mucoepidermoid eccrine ca.: very rare; squamoid with goblets.
    • apocrine: clues = decap apical blebs, teats, snouts & nuclei eccentric, oval, vesicular & prominent nucleoli & relatively abundant granular cytoplasm. IHC = while may be EMA & CEA pos., GCDFP-15 pos. specificity & very sensitive marker, too2). Special stains = PAS & mucicarmine pos. cytoplasmic droplets.
      • extramammary Paget's disease: IHC ck7 & GCDFP-15 pos.; behavior: indolent when entirely intraepidermal, but even (1% of cases) focal microinvasion means 20-30% already have node mets. [LMC-02-6954], so SLN biopsy.
      • ductopapillary apocrine ca.: 30-50% mets...especially in eyelids (liver & sometimes bone) [LMC-04-10771], so SLN or if clinical adenopathy.
      • primary signet ring ca. of skin: is very rare & when you think of this it is almost always a met from a viceral signet ring cancer2.
    • mixed adnexal ca.: eccrine plus apocrine &/or plus sebaceous or follicular.
    • undifferentiated adnexal (lymphopitheliomalike) ca. of skin: behaior very indolent with total excision; looks like nasopharyngeal ca. & often has at least foci of other adnexal diff.
    • Sebaceous gland malignancies: Leu-M1 pos.2; some granular or bubbly lipid cytoplasm & scalloped nuclei [S-02-508; S-03-3290; S-03-13005 adenoma]; there are mixed seb. & other adnexal...see above2; there are extra-cutaneous sebaceous tumors of oral cavity & salivary glands.
      • occular skin based: behaviors differ greatly but prone to met to other skin sites,
        1. low-grade pattern: indolent.
        2. intermediate grade pattern: aggressive.
        3. high grade pattern (medullary like): aggressive.
      • extra-occular: widely excise & biopsy clinically pos. nodes.
    • Hair follicle malignancies: pilar differentiation is suggested by ghost cells, trchilemmal keratinization/granules (outer root sheath analogue), PAS pos. hyalinized stroma or even H&E basement membrane thickening (hyaline mantle), trichoid keratinous microcysts and/or cell balls with or without peripheral palisading, trichoid abortive hair bulbs, catagen-like apoptotic bodies, CD34+ periepithelial stromal spindle cells, intra-lesional colonization of epithelial nests by HMB45+ dendritic melanocytes, and eosinophilic or clear cytoplasmic change4.
      • epithelial:
        • malignant proliferating pilar tumor:
          1. low grade: locally recurr...excise.
          2. high grade: locally recurr & distant mets.
        • trichilemmal carcinoma: SCC-like (no tendency to node mets) but with keratinization being of trichilemmal type 2(p.151) & brisk mitotic & maybe clear-cell-like; fairly indolent2 [S-04-14528].
        • pilomatrix carcinoma: infiltrating borders & mitotic.
        • trichoepithelial carcinoma
        • trichofollicular carcinoma
        • trichogerminoma: well circumscribed, highly cellular, deep-dermal, monotonous basaloid cells (may see peripheral palisading) /w round nuclei & dispersed chromatin, distinct nucleoli, and often many mitoses4.
      • other:
        • carcinoma ex dilated pore of Winer
    • Merkle cell carcinoma: [LMC-04-4712; S-04-6420] [IHC stain pattern] CD20 dot-positive.
    • other:
      1. primary cutaneous lymphoma [S-00-10998]
      2. secondary cutaneous lymphoma (can mimic Kaposi's) [S-01-11267]
      3. metastatic ca:
        • herald mets (first indication of an internal cancer): lung, kidney, stomach, and internal female genitals
        • late mets (at end stage of visceral cancer): breast, lung, GI tract, & oropharynx
      4. Kaposi's sarcoma: HIV-immunodeficiency associated vs. other Kaposi's
      5. atypical fibroxanthoma (AFX): nodular and usually sun exposed skin in elderly (histiocyte IHC reactions) (small, superficial MFHs 1)[S-02-10165C]
      6. borderline fibrous histiocytoma (between DF and MFH)
      7. malignant fibrous histiocytoma (MFH) [S-01-9887]; must be K903 negative (spindled SCC positive).
      8. DFSP [LMC-03-6618]
      9. neural [IHC]

    References:

    1. Ackerman's Surgical Pathology, 8th Ed., Juan Rosai, 1996 (EBS's office)
    2. Cutaneous Adnexal Tumors..., Wick MR & Swanson PE, 1991, 238 pages (BWD's office).
    3. Maize J, case consults notes
    4. letter, Histopathology 46(1):108-9, Jan. 2005.
    5. MAC in eMedicine, Gee BC, as of 22 August 2005.
    6. Smith KJ, et. al., MAC & IHC, Am J Surg Pathol. 2001 Apr;25(4):464-71.
    7. Am. J. Dermatopath. 26(4):463-71, Dec. 2004.
    8. McKee, Calonje, & Granter, Pathology of The Skin... Two volumes, 3rd Ed. 2005.

    (posted 22 August 2003; latest addition 30 May 2007)
 
© Copyright 1999 - 2006, all rights reserved, Pathology Associates Of Lexington, P.A.