Skin nonmelanocytic tumor
Lymphoma and related disorders (see also Lymphoma chapter)
Leukemic infiltrates of skin and cutaneous mastocytosis
Cutaneous mastocytosis
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Last staff update: 21 September 2023
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PubMed Search: Mast cell disorders skin
See Also: Systemic mastocytosis
Table of Contents
Definition / general | Clinical features | Case reports | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Differential diagnosisCite this page: Hale CS., Hamodat M. Cutaneous mastocytosis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticmastcell.html. Accessed April 20th, 2024.
Definition / general
- Most cutaneous mast cell disorders have a good prognosis
- Mastocytosis: monomorphic population of mast cells with rare eosinophils
- Telangiectasia macularis eruptive perstans (TMEP): telangiectatic light or dark brown macules
- Urticaria pigmentosa: common form of mastocytosis, numerous small yellow brown papules, become hives when rubbed
Clinical features
- At birth or during the first 3 months of life
- May present with flushing attacks due to high histamine content
- Spontaneous involution frequently occurs
- CD117 mutations in patients with mastocytosis
- Urticaria pigmentosa: most common form of mastocytosis of skin; usually childhood onset of multiple brown macules; systemic variant is malignant and involves liver, spleen, bone marrow, lymph nodes and occasionally peripheral blood (mast cell leukemia)
- Darier's sign: stroking skin releases histamine, causing hives
- Dermatographism: dermal edema resembling hives due to stroking with pointed instrument
- Description:
- Solitary lesion, or small group as part of urticaria pigmentosa
- Affect extremities and trunk, not palms and soles
- May blister
- Red, brown pink or yellow nodules, or plaques measuring up to 1.0 cm
Case reports
- 2 year old boy with itchy brown skin macules (Case of the Week #344)
- 53 year old man with erythematous macules and telangiectasia on arm (J Clin Aesthet Dermatol 2011;4:52)
Clinical images
Contributed by Mark R. Wick, M.D.
Breast skin
Images hosted on other servers:
Erythematous macules with telangiectasia
Telangiectatic macules in the scapular area
Microscopic (histologic) description
- Within the macules and plaque, mast cells are predominantly in papillary dermis
- Mast cells are round or spindle shaped with abundant eosinophilic cytoplasm, distinct cytoplasmic boundaries, large pale nuclei
- Eosinophils are often present
- Also edema of papillary dermis, subepidermal vesiculation
- Bullous mastocytosis may be diagnosed by Tzank smear; infiltrate may be slight and perivascular
- In telangiectasia macularis eruptive perstans, features may be subtle, with increased mast cells around dilated superficial capillaries, basal cell hyperpigmentation of overlying epidermis, superficial lymphohistiocytic infiltrate
Microscopic (histologic) images
Contributed by Mark R. Wick, M.D. and Case #344
Mastocytoma
Mastocytosis
Leder
Giemsa
Toluidine blue
Mastocytosis
Breast skin
Urticaria pigmentosa, breast skin
Leder stain, breast
H&E
Toluidine blue
Positive stains
- Toluidine blue and Giemsa demonstrate metachromasia (granules are purple red)
- Leder (chloroacetate esterase), CD117 / c-kit
Differential diagnosis
- Normal skin or dermatoses:
- Must search to find mast cells even with special stains
- Chronic dermatitis, nodular prurigo, and venous stasis:
- Typically associated with granulation tissue and foci of neovascularization
