Dr Sampurna Roy
MD
 Site created by Dr Sampurna Roy MD
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Benign sweat gland tumours Cysts: Hydrocystoma -Eccrine/Apocrine Porokeratotic eccrine ostial naevus Benign Neoplasms: Syringocystadenoma Papilliferum Chondroid Syringoma (benign mixed tumour) Low grade: Primary extramammary Paget’s disease Intermediate grade: Digital papillary adenocarcinoma High grade: |
| Sebaceous tumours |
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Tumours of the Hair Follicle Hair Germ Differentiation: Desmoplastic Trichoepithelioma
Cutaneous lymphadenoma Tumour of Follicular Infundibulum Outer root
sheath differentiation: Proliferating Trichilemmal Cyst (Pilar Tumour)
Matrical differentiation: |
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Melanocytic tumours
Mongolian Spots /Ota's naevus /Ito's naevus Pigmented melanocytic lesions causing diagnostic problems Prognostic parameters of melanoma Superficial spreading melanoma |
Trichoepithelioma is regarded as a poorly differentiated hamartoma of the hair germ. Although most classifications include this as a separate entity Ackerman and his colleagues have suggested that such tumours should be grouped together with trichoblastomas and use the term "trichoblastoma" for all tumours showing predominant hair germ differentiation. Site: Commonly located on the head and neck region. Solitary- Nose, upper lip and cheeks. Multiple- Central part of the face, trunk, neck & scalp. Clinical presentation: Skin coloured papules. May be solitary or multiple. Papules may coalesce to form plaques. Rare presentation is a linear form. Multiple tumours (epithelioma adenoides cysticum) inherited as autosomal dominant. Brooke-Spiegler syndrome: Multiple trichoepitheliomas and cylindromas. Microscopic features : Well circumscribed dermal tumour ; Islands, nests and cords of uniform basaloid cells ; Cells are set in a variably cellular fibrous stroma ; Epithelial structures resemble hair papillae or abortive hair follicle ; Small keratocysts (infundibular differentiation) lined by stratified squamous epithelium ; Retraction of stroma from adjacent dermis ; Foci of calcification are often present ; Few mitotic figures and apoptotic bodies. Immature trichoepithelioma: Typically exhibits no horn cysts, displays fewer primitive hair structures, and lacks the adenoidal growth patterns of the tumour lobules which are usually present in the classical trichoepitheliomas. Differential diagnosis : 1. Basal cell carcinoma; Distinction from some types of basal cell carcinoma has been based on the paucity of mitoses and apoptotic bodies, lack of retraction between stroma and epithelium and presence of primitive follicles in trichoepithelioma and differences in CD34 and bcl2 expression. However, there are some tumours in which this distinction cannot be reliably made. 2. Microcystic adnexal carcinoma ; 4. Trichoadenoma ; 5.Trichoblastoma ; DESMOPLASTIC TRICHOEPITHELIOMA: Desmoplastic trichoepithelioma is a benign neoplasm considered to have follicular differentiation. Its sweat gland- or sebaceous-lines of differentiation have been also reported. The cells in desmoplastic trichoepithelioma are suggested to be in close association with the basal cells in the outer root sheath. Diagnosis of this lesion is important because it may be mistaken for Microcystic adnexal carcinoma clinically and histologically. This condition should not be diagnosed on shave, curettage or punch biopsies. Deep biopsy is necessary to identify subcutaneous involvement. Clinical presentation: Presents as a solitary , small indurated often depressed plaque on the face. Microscopic features:
Symmetrical well-circumscribed ; Lesions are usually located
in the mid and upper dermis ; Tumour consists of cords and small nests
of uniform basaloid cells in a dense fibrotic stroma ; Superficially,
small horn cysts and keratin granulomas may be present ; No ductal
differentiation. 1.Syringoma - Usually periorbital and multiple lesions ; Narrow strands of tumour cells ; Horn cysts, foreign body granuloma or calcifications are rare. 2.Morpheic basal cell carcinoma - Form clefts between the nests and the stroma ; Coexisting nodular basal cell carcinoma; Mitoses and apoptotic bodies are common; Foreign body granulomas and ruptured keratinous cysts are rare. 3.Microcystic adnexal carcinoma: click 4.Metastatic breast carcinoma |
Surgical-Pathology.com
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Gross examination of the skin specimen |
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Cutaneous infection and infestations Histopathological patterns in cutaneous infections : Bacterial, Rickettsial and Chlamydial infection |