Sec 23 Tumors and Hyperplasia of the Dermis and Subcutaneous Fat Flashcards
Heterogeneous group of mesenchymal neoplasm
Malignant fibrohistiocytic tumors
The diagnosis of fibrohistiocytic tumors is done principally on the basis
H and E-stained section
Represent the malignant end of a spectrum that begins with fibroplasias and benign fibrous tumors
Malignant fibrohistiocytic tumors of the dermis
Most common soft tissue tumor of advanced adulthood
Malignant fibrous histiocytoma (pleomorphic type)
Primary treatment of choice for “so-called malignant fibrohistiocytic tumors”
Surgery
Most common cutaneous sarcoma
Dermatofibrosarcoma protuberans
Can present at birth or in children but most patients are middle-aged adult characterized cytogenetically by a reciprocal translocation t(17;22) (q22;q13), or more frequently, a supernumerary ring chromosome composed of hybrid material derived from t(17;22)
Dermatofibrosarcoma protuberans
Encodes the β chain of the PDGF, a ligand for the cell- surface receptor tyrosine kinase PDGFR, which is a growth factor that acts as a potent mitogen for a variety of connective tissue cells
PDFGB gene
Slow-growing lesion that often presents on the trunk and proximal extremities; due to its indolent onset, the patient may present rather late when the tumor is already several centimeters in size; often misdiagnosed as a simple scar, keloid, or cyst
Dermatofibrosarcoma protuberans
Most common presentation is a firm, indurated plaque, often skin-colored with red–brown exophytic nodules
Dermatofibrosarcoma protuberans
The pigmented variant of DFSP
Bednar tumor
Considered the juvenile variant of DSFP, typically presents as a dermal or subcutaneous mass, which most frequently involves the trunk, thigh, or inguinal region
Giant cell fibroblastoma
Histopathology: dermal proliferation of monomorphous, slender, or slightly plump spindle cells with little pleomorphism arranged in a storiform pattern; epidermis is usually uninvolved; proliferation commonly infiltrates the subcutaneous fat along the fibrous septa, isolating adipocytes to form lucencies (“honeycomb” pattern)
Dermatofibrosarcoma protuberans
Histopathology: characterized by giant cells, irregular vascular-like space partially ligned by giant cells as well as myxoid to collagenous areas with elongated to stellated cells
Giant cell fibroblastoma
Very sensitive, although nonspecific, marker for DFSP
CD34
Most common site of metastasis in DFSP
Lung
Nodes
Standard management: DFSP
Complete local surgical resection with margins of 1-3 cm (recurrence rate: 13-52%)
Competitive antagonists of the adenosine triphosphate (ATP)-binding site, blocking the transfer of phosphate groups from ATP to tyrosine kinase residues of the substrates
Tyrosine Kinase Inhibitors: imatinib or nilotinib
Rare tumors that occur sporadically, can be associated with familial adenomatous polyposis (FAP), history of trauma or an operation; presents as slowly growing tumors that may arise from the muscular aponeuroses at any site of the body, but are most commonly found on the trunk and extremities which can be painless or minimally painful
Desmoid tumors, or Aggressive fibromatosis
Histopathology: monoclonal fibroblastic proliferation typically arising from muscular or aponeurotic structures but lacks nuclear and cytoplasmic features of malignancy; consist of spindle-shaped cells, separated by collagen fibers
Desmoid tumor
Rare, rapidly growing neoplasm of intermediate malignant potential which occurs mainly on sun-exposed skin (face, neck, and hands) of elderly individuals, presents as asymptomatic, solitary, often dome-shaped nodule, which may be eroded or ulcerated with sun-damaged skin
Atypical fibroxathoma
Represents a predisposing factor in the pathogenesis of AFX
Solar radiation
Histopathology: poorly circumscribed hypercellular tumor that may extend deeply into the reticular dermis; consists of an admixture of highly pleomorphic spindle, epithelioid (histiocyte-like), and multinucleated giant cells in the dermis; pronounced atypia, with bizarre, large, round, or ovoid hyperchromatic nuclei with numerous mitotic figures, large prominent eosinophilic nucleoli; and abundant, vacuolated cytoplasm
Atypical fibroxathoma
Useful markers in highly proliferative AFX
MIB-1 and Ki-67
Treatment: Atypical fibroxathoma
Surgery
Mohs micrographic surgery has less recurrence rate versus local excision
Represents a spectrum of malignant myxoid tumors of fibroblastic origin, presents as gradually enlarging painless dermal or subcutaneous mass on the extremities and limb girdles, but may also arise within the head and neck region, the trunk, hands, and feet
Myxofibrosarcoma
Most common malignant mesenchymal neoplasm of the extremities/limb girdles of older adults
Myxofibrosarcoma
Histopathology: characterized by variable amounts of hyaluronic acid-rich myxoid stroma, delicate blood vessels, and spindle- shaped or stellate fibroblasts
Myxofibrosarcoma
Histopathology: hypocellular tumors comprised of relatively uniformly appearing spindle or stellate cells dispersed within a myxoid matrix; while nuclear pleomorphism and hyperchromasia may be present, mitotic figures and other overtly malignant features are absent
Low grade Myxofibrosarcoma
Histopathology: characterized by hypercellularity, marked nuclear atypia, hemorrhage and necrosis, and a high mitotic rate
High grade Myxofibrosarcoma
Primary therapy for Myxofibrosarcoma
Local surgical resection (wide and deep) with 3 cm margins
Most common metastatic sites for Myxofibrosarcoma
Lung
Bones
Almost never a cutaneous tumor but involved as a result of direct extension or metastasis, found in the subcutaneous tissue
Undifferentiated Pleomorphic Sarcoma
Histopathology: spindle cells in a storiform pattern; stroma may be finely fibrillary, myxoid, or densely collagenous; bizarre epithelioid and giant cells may be present and may contain small amounts of lipid
Undifferentiated Pleomorphic Sarcoma
Relatively rare soft-tissue sarcoma of unknown histogenesis, presents as a painless, slow-growing, firm tumor often accompanied by superficial ulceration, hemorrhage, necrosis, and plaques; may grow to a large size, up to 20 cm in diameter
Epithelioid Sarcoma
Histopathology: characterized by marked cytologic atypia, frequent mitosis, vascular invasion, and absence of a granulomatous appearance; tumor cells are large epithelioid and may mimic a carcinoma; cells with a rhabdoid morphology can be seen
Proximal Epithelioid Sarcoma
Histopathology: nodules composed of relatively uniform polygonal cells, often with loss of cohesion, which merge in the periphery into spindle cells without demarcation; have relatively abundant deeply eosinophilic cytoplasm; mitotic figures are rare and only minimal pleomorphism is evident; stromal changes include desmoplasia with cords of bland spindle cells sometimes with storiform pattern; nodules frequently have central necrosis; hemorrhage is frequently observed
Classic Epithelioid Sarcoma
Treatment of choice: Epithelioid Sarcoma
Radical excision traditionally with clear margins
Chemotherapy for Metastatic Epithelioid Sarcoma
Doxorubicin
Ifosfamide
Most common benign tumors of childhood, occurring in approximately 4% of children by 1 year of age
Infantile hemangioma
Expressed in all stages of hemangioma maturation
GLUT1, a glucose transporter protein
Absence at birth or presence as a premonitory mark, usually an area of pallor, telangiectasias, or duskiness is characteristic
Infantile hemangioma
Always become apparent within the 1st month of life, period of most rapid growth typically occurs within the 1st 5 months of life, with 80% of growth being completed by 5 months of age
Infantile hemangioma
Most IH complete their course by the age
7-10 years old
Involve the upper dermis, with a bright strawberry red color
Superficial hemangiomas
Involving both super cial and deeper skin structures, have bright strawberry red color and skin color to blue in color
Mixed hemangiomas
Present as a localized, firm, rubbery subcutaneous mass that can be slightly raised with a bluish color or with telangiectasias involving the overlying skin, or may be deep enough that the overlying skin is completely flat and of normal hue
Deep Infantile Hemangioma
One of the most important factors affecting risk in Infantile Hemangioma
Anatomic location
A neurocutaneous syndrome that consists of the following features: posterior fossa brain malformations, segmental cervicofacial hemangioma, arterial anomalies, cardiac defects or coarctation of the aorta, eye anomalies, and sternal defects, such as sternal clefting or supraumbilical raphe
PHACE
Diagnosed PHACE syndrome
Facial hemangioma >5 cm in diameter +
1 major criterion or 2 minor criteria
Possible PHACE syndrome
Facial hemangioma >5 cm in diameter + 1 minor criterion or
Hemangioma of the neck or upper torso + 1 major criterion or 2 minor criteria or
No hemangioma + 2 major criteria
PHACE: Cerebrovascular
Major:
Anomaly of major cerebral arteries
-Dysplasia of the large cerebral arteries
-Arterial stenosis or occlusion with or without moyamoya collaterals
-Absence or moderate to severe hypoplasia of the large cerebral arteries
-Aberrant origin or course of the large cerebral arteries-
-Persistent trigeminal artery
-Saccular aneurysms of any cerebral arteries
Minor:
Persistent embryonic artery other than trigeminal artery
-Proatlantal intersegmental artery (types 1 and 2)
-Primitive hypoglossal artery
-Primitive otic artery
PHACE: Structural brain
Major:
Posterior fossa anomaly
Dandy-Walker complex or unilateral/bilateral cerebellar hypoplasia/dysplasia
Minor:
Enhancing extra-axial lesion with features consistent with intracranial hemangioma
-Midline anomaly
-Neuronal migration disorderd
PHACE: Cardiovascular
Major: Aortic arch anomaly -Coarctation of aorta dysplasia -Aneurysm Minor: Ventricular septal defect -Right aortic arch (double aortic arch) -Aberrant origin of the subclavian artery with or without a vascular ring
PHACE: Ocular
Major: Posterior segment abnormality -Persistent fetal vasculature (persistent hyperplastic primary vitreous) -Retinal vascular anomalies -Morning glory disc anomaly optic nerve hypoplasia -Peripapillary staphyloma -Coloboma Minor: Anterior segment abnormality Sclerocornea -Cataract -Coloboma -Microphthalmia
PHACE: Ventral or midline
Major: Sternal defect -Sternal cleft -Supraumbilical raphe -Sternal defects Minor: Hypopituitarism -Ectopic thyroid
Most common cardiac anomaly in PHACE
Coarctation of the aorta, most often involving the transverse aorta
Infants with periocular hemangiomas are at risk for these which if untreated, can lead to permanent visual loss
Anisometropia
Amblyopia
Segmental hemangiomas involving the preauricular, mandibular, chin, and neck skin which have a 60% risk of having symptomatic airway disease
“Beard area” hemangioma
Often present with the insidious onset of biphasic stridor between weeks 4 and 12 of life and are often mistakenly diagnosed as tracheomalacia, upper respiratory infection, or croup
Airway hemangiomas
PELVIS syndrome
Perineal hemangioma External genitlia malformations Lipomyelomeningocele Vesicorenal abnormalities Imperforate anus Skin tag
SACRAL syndrome
Spinal dysraphism Anogenital anomalies Cutaneous anomalies, Renal and urologic anomalies Associated with angioma of Lumbosacral localization
Infants with multifocal vascular tumors and extracutaneous disease
Diffuse neonatal hemangiomatosis
Most common extracutaneous site of Infantile Hemangioma
Liver