Rare skin tumours COPY Flashcards
Tumours we are covering
Tumours of fibrous tissue Merkel cell carcinoma Angiosarcoma Adnexal tumours Sebaceous tumours
Tumours of fibrous tissue
Atypical fibroxanthoma
Malignant fibrous histiocytoma (Malignant part of above) Dermatofibrosarcoma protuberans
Atypical fibroxanthoma
elderly - Mainly men sun exposed - Usually head rapidly enlarging reddish dome shaped nodule often eroded or crusted surface darker hue dt hemosiderin deposition
dermoscopy: reddish and whitish areas - majority non pigmented white structureless and or red structureless white lines may have white circles polymorphous vascular pattern - vessels usually fine, linear ulceration, crusting and keratin masses
tendency to recur after incomplete excision > wide local excision
excellent prognosis
Malignant histiocytoma
elderly sun exposed enlarging subcutaneous nodule, may have significant size and ulcerate
ddx: bcc, scc, melanoma
dermoscopy: Polymorphous vessels Ulceration Hemorrhage
overall survival 50% aggressive tumour metastasizes
Adnexal tumours - classification
follicular
sebaceous
eccrine
apocrine
Adnexal tumour with associated syndromes
Cyclindroma
Spiradenoma
Trichodiscoma
Trichilemmoma
Sebaceous tumours
Keratoacanthomas
Brooke-Spiegler syndrome
Multiple skin tumours Developing from skin appendages
Spiradenomas
Cylindromas
Trichoepitheliomas
Cylindroma and spiradenoma —
Cylindromas and spiradenomas are sweat duct tumors centered in the dermis that often show overlapping features in the same tumor (spiradenocylindroma). They occur sporadically in the older adult population, typically as a solitary papule or nodule on the head or neck or, less commonly, on the trunk and extremities (picture 1B, 1D). Detection of multiple cylindromas (picture 12) or spiradenomas should raise the suspicion of Brooke-Spiegler syndrome or familial cylindromatosis caused by mutation of CYLD. (See ‘Syndromes associated with cutaneous adnexal tumors’ below.)
Trichoblastoma and trichoepithelioma —
Trichoblastoma and trichoepithelioma are benign epithelial tumors composed of follicular germinative cells resembling those seen in the embryologic buds of primitive folliculosebaceous units. They present as smooth, nonulcerated, skin-colored papules, sometimes with associated telangiectasias usually located on the head and neck . The majority of cases occur in adults after the age of 40. The presence of multiple trichoepitheliomas should raise the suspicion of Brooke-Spiegler syndrome or multiple familial trichoepithelioma.
Birt-Hogg-Dube syndrome
Multiple trichodiscomas Associated with benign and malignant renal neoplasms, Lung cysts Spontaneous pneumothorax
Trichodiscoma and fibrofolliculoma —
Although originally described as distinct entities, evidence suggests that trichodiscomas and fibrofolliculomas represent a spectrum of the same neoplastic process [80]. There is also overlap with perifollicular fibroma (angiofibroma). Both fibrofolliculoma and trichodiscoma present as small, 2 to 4 mm, dome-shaped, skin-colored papules on the face, scalp, ears, or upper trunk. They occur sporadically in adults and are seen in multiplicity in patients with Birt-Hogg-Dubé syndrome
Cowden syndrome
AKA multiple hamartoma syndrome.
The common lesions are trichilemmomas, acral keratoses, and facial papules/oral papillomas
Young age Trichilemmoma Oral mucosal papillomatosis Acral keratoses Palmoplantar keratoses Associated with malignancy - breast Ca, thyroid Ca, Colon Ca, Renal cell Ca. Usually the dermatologist is last one to see the patient.
Trichilemmomas
hamartomatous tumors of the outer root sheath of the hair follicle or other skin appendages that occur on the face and neck of patients with Cowden syndrome. Trichilemmoma is a clinically significant sign of Cowden syndrome when seen in multiplicity (three or more). They present as wart-like, skin-colored papules with slightly rough surfaces; histologically, the lesions contain large glycogen-rich cells [44]. Clinically, trichilemmomas are indistinguishable from trichoepitheliomas and other benign follicular tumors affecting the pilosebaceous unit, including fibrofolliculomas and trichodiscomas (which are characteristic lesions of Birt-Hogg-Dube syndrome) [45]. At least one lesion should be biopsied given the difficulty with clinical diagnosis [46]. (See “Birt-Hogg-Dubé syndrome”.)
A trichilemmoma is rarely a sporadic feature. One study found a complete loss of PTEN expression by immunohistochemistry in five of six (83 percent) trichilemmomas from patients with Cowden syndrome compared with only 1 of 33 (3 percent) sporadic trichilemmomas [47]
Muir Torre Syndrome
Phenotypic variant of Lynch syndrome (non polyposis colon cancer syndrome) Autosomal dominant Sebaceous tumours Multiple keratoacanthoma Early onset visceral tumours (Colon and urinary tract)
Which sebaceous tumours are associated with Muir Torre Syndrome?
Sebaceomas Sebaceous adenoma Sebaceous carcinoma
Trichilemmoma - associated syndrome
Cowden syndrome
Dermatofibrosarcoma protuburans - clinical
one or more firm, erythematous nodules or plaques resembles scar but no h/o scar may enlarge slowly over many years May ulcerated or suppurate
Dermatofibrosarcoma protuburans - incidence
1% of soft tissue sarcomas most common cutaneous sarcoma
Dermatofibrosarcoma protuburans - Ddx
dermatofibroma
Dermatofibrosarcoma protuburans - Dermoscopy
reddish background colour fine linear vessels - may be arborizing no criteria for dermatofibroma
Dermatofibrosarcoma protuburans - Malignant potential
Low to intermediate rarely metastasizes locally aggressive high recurrence rate
Dermatofibrosarcoma protuburans - management
Wide local excision - 5 cm
Cutaneous angiosarcoma of head and neck - clinical
Unique entity elderly men poor prognosis
Cutaneous angiosarcoma - associated with lymphedema
occurring years after radiation occurring after years of lymphedema
