Diagnosis of Path Case24:
Aneurysmal variant of
dermatofibroma -
Case history and images:
This
is a common dermal tumour which usually occurs on the extremities in
young adults. Fibrous histiocytoma is regarded as a neoplastic lesion by
some authors and an inflammatory or reactive process by others.
Gross:
These are usually
solitary round or ovoid firm nodule,less than 1cm in diameter. Aneurysmal
variant may be upto 10 cms in diameter. Dark brown or red in colour. Cream
or yellowish cut surface in tumour with abundant lipid.
Microscopic features:(Dr Weems)
IMAGE LINK1 ;
2
1. Symmetric lesion in
the dermis.
2. Epidermal hyperplasia is usually present.
3. Grenz zone is noted in almost 70% cases.
4. Rarely extend into superficial subcutis (as a well defined bulge or septal
extension).
5. Storiform growth pattern.
6. Mixed population of cells (fibrocytic,histiocytic or mixed).
7. Hyalinized collagen fibers surrounded by spindle cells at the periphery
- (keloidal pattern)
8. Birefringence of intralesional collagen with polarization present .
Various changes may be
present in the overlying epidermis:
1. Acanthosis with basal
hyperpigmentation; 2.Seborrheic keratosis like pattern; 3. Epidermal
atrophy; 4. Intraepidermal carcinoma; 5. Basaloid hyperplasia with
rudimentary pilar structure (difficult to distinguish from basal
cell carcinoma) ; 8. Sebaceous structures IMAGE1
;
IMAGE2
(Dr Weems)
Abstract:
Anti-cytokeratin
20 staining of Merkel cells helps differentiate basaloid proliferations
overlying dermatofibromas from basal cell carcinoma. J
Cutan Pathol. 2005 Aug;32(7):491-5
Follicular basal cell hyperplasia overlying dermatofibroma.Am
J Surg Pathol.1997;21(6): 711-8
Sebaceous hyperplasia: a clue to
the diagnosis of dermatofibroma.J
Am Acad Dermatol. 2001
Jan;44(1):94-5
Plate-like sebaceous hyperplasia
overlying dermatofibroma. J
Cutan Pathol. 1992;19(3):253-5
Proliferation and differentiation
of the keratinocytes in hyperplastic epidermis overlying dermatofibroma:
immunohistochemical characterization.
Am J Dermatopathol.
2001 ;23(2):90-8.
Dermatofibroma may be associated
with melanocytic lesions.
Melanocytic lesions associated with dermatofibromas: a
spectrum of lesions ranging from junctional nevus to malignant melanoma in
situ.
Mod Pathol. 2005;18(8):1043-7
Dermatofibroma may occur in patients associated with HIV infection.
Multiple eruptive dermatofibromas
in three men with HIV infection.
Dermatology.1997;
195(4):344-8
Presence of Leishmania organisms
in specific and non-specific skin lesions in HIV-infected individuals with
visceral leishmaniasis.
Int J
Dermatol. 2002 ;41
(10) :670-5
Differential diagnosis of dermatofibroma:
Dermatofibrosarcoma protuberans: CD34+ or +/- ; Factor XIIIa negative, monomorphic population of cells,
irregularly infiltrative at the periphery, honeycomb pattern of
infiltration into the subcutis).
Abstract:
Dermatofibroma and
dermatofibrosarcoma protuberans: an immunohistochemical study reveals
distinctive antigenic profiles.J
Dermatol Sci. 1996
Jan;11(1):1-9.
Deep penetrating dermatofibroma versus
dermatofibrosarcoma protuberans. A clinicopathologic comparison.Am
J Surg Pathol. 1994 Jul;18(7):677-86
The pathological distinction
between "deep penetrating" dermatofibroma and dermatofibrosarcoma
protuberans.Semin
Cutan Med Surg. 1999
Mar;18(1):91-8
CD34 and factor-XIIIa
immunoreactivity in dermatofibrosarcoma protuberans and dermatofibroma.Am
J Dermatopathol. 1997
Apr;19(2):147-53
Tenascin differentiates
dermatofibroma from dermatofibrosarcoma protuberans: comparison with CD34
and factor XIIIa.Hum
Pathol. 2001
Jan;32(1):50-6.
Atypical fibroxanthoma
; scar ; keloid ; some hemangiomas,
Giant cell fibroblastoma;
Sclerotic fibroma;
dermal
nodular fasciitis; Dermal dendrocytoma;Giant cell collagenoma;Pleomorphic fibroma;
Abstract:
Differential expression of factor XIIIa and CD34 in
cutaneous mesenchymal tumors.
J Cutan Pathol. 1993 Apr;20(2):154-8.
Medallion-like
dermal dendrocyte hamartoma: a new clinically and histopathologically
distinct lesion.J Am Acad Dermatol. 2004
Sep;51(3):359-63.
CD34-reactive myxoid dermal
dendrocytoma.Am
J Dermatopathol.2002;24(1):50-3
Giant cell collagenoma:
a benign dermal tumor with distinctive multinucleate cells. Am J Surg
Pathol 1998 May;22(5):557-63.
Giant cell collagenoma:
case report and review of the literature.J Cutan Pathol 2002
Jan;29(1):48-51
Subungual
pleomorphic fibroma. J Cutan Pathol. 2003 Oct;30(9):569-71
Sclerotic fibroma-like
dermatofibroma: an uncommon distinctive variant of dermatofibroma.Histol
Histopathol. 2005
Jul;20(3):801-6.
Dermatofibroma with sclerotic
areas resembling a sclerotic fibroma of the skin.J
Cutan Pathol. 2002
Jan;29(1):44-7
Sporadic
sclerotic fibroma of the oral soft tissues.
Am J Dermatopathol. 2004;26 (3):182-7
Solitary
sclerotic fibroma of skin: a possible link with pleomorphic fibroma with
immunophenotypic expression for O13 (CD99) and CD34
J Cutan
Pathol 2003; 30:631-636
- Presents as an exophytic nodule.
- It is a dermal tumour that can mimic melanocytic, vascular,
epithelial, or other histiocytic lesions. It is usually located on the extremities in adults.
- Microscopically, it is a polypoid lesion with epidermal collarette.
- Most striking feature is the presence of sheets of angulated epithelioid
with abundant eosinophilic cytoplasm (resemble
Spitz
naevus).
- No junctional component or theques noted.
- Giant cells, xanthoma cells and vascular spaces may be present.
- S100 and HMB45- negative, Factor XIIIa - positive, Vimentin- positive,
CD31,CD34- negative in the tumour cells but highlight the blood vessels.
Abstract:Immunohistochemical distinction of epithelioid
histiocytic proliferations from epithelioid melanocytic nevi. Am
J Dermatopathol. 2000;22(3):237-41
Epithelioid cell
histiocytoma - histogenetic and kinetics analysis of dermal microvascular
unit dendritic cell subpopulations.JCutan Pathol.2003;30(7):415-22
Epithelioid benign fibrous
histiocytoma of skin: clinico-pathological analysis of 20 cases of a
poorly known variant. Histopathology.
1994;24(2):123-9.
Epithelioid cell
histiocytoma. A report of 10 cases including a new cellular variant.Am J
Surg Pathol 1994;18(6):583-90
Epithelioid cell histiocytoma: a
simulant of vascular and melanocytic neoplasms. Am
J Dermatopathol. 1999
Feb;21(1):1-7
Cellular 'neurothekeoma': an
epithelioid variant of dermatofibroma? Histopathology.
1998 May;32(5):414-22.
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