ABPath Dermatopathology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Munro microabscess

Collection of neutrophils within the stratum corneum, classically seen in psoriasis and reflecting transepidermal migration of inflammatory cells.

Acantholysis

Loss of cohesion between keratinocytes due to disruption of desmosomes, producing intraepidermal clefts as in pemphigus vulgaris.

Pautrier microabscess

Intraepidermal cluster of atypical lymphocytes, a characteristic finding in mycosis fungoides and other epidermotropic T-cell lymphomas.

Civatte body

Apoptotic keratinocyte appearing as a small eosinophilic round body near the dermoepidermal junction, typical of lichen planus.

Lupus band test

Granular deposition of immunoglobulin and complement along the basement membrane zone on direct immunofluorescence in lupus erythematosus.

Tombstone row

Basal keratinocytes remaining attached to the basement membrane after suprabasal acantholysis, resembling tombstones in pemphigus vulgaris.

Breslow thickness

Maximum vertical depth of melanoma invasion measured in millimeters from the granular layer to the deepest tumor cell.

Spongiosis

Intercellular edema between keratinocytes that widens intercellular spaces and stretches desmosomes, characteristic of eczematous dermatitis.

Palisading granuloma

Granulomatous inflammation with histiocytes arranged around a central zone, as seen in granuloma annulare and necrobiosis lipoidica.

Dermoscopy

Magnified surface examination of skin lesions using polarized or nonpolarized light to assess pigment networks and vascular patterns.

Pigment network

Dermoscopic grid of pigmented lines over rete ridges; regular network suggests a benign melanocytic lesion, irregular network suggests melanoma.

Blue-white veil

Dermoscopic structureless blue-white area overlying a lesion, associated with melanin in the dermis and suggestive of melanoma.

Direct immunofluorescence

Technique using fluorophore-labeled antibodies on fresh perilesional tissue to detect immune deposits in blistering and connective tissue diseases.

Punch biopsy

Cylindrical full-thickness skin specimen obtained with a round blade, typically 3 to 4 millimeters, used for inflammatory and deep lesions.

Shave biopsy

Horizontal sampling of superficial skin using a blade; useful for epidermal lesions but may preclude accurate depth measurement in melanoma.

H&E stain

Routine histologic stain in which hematoxylin colors nuclei blue-purple and eosin colors cytoplasm and collagen pink.

Polarization microscopy

Microscopic technique using polarized light to identify birefringent materials such as foreign bodies and collagen.

SOX10

Nuclear transcription factor marker expressed in melanocytes, Schwann cells, and myoepithelial cells; useful in melanoma diagnosis.

Melan-A

Cytoplasmic immunohistochemical marker of melanocytic differentiation, useful in identifying melanoma and distinguishing it from carcinoma.

CD34

Transmembrane glycoprotein marker of vascular endothelium and dermal dendrocytes; positive in dermatofibrosarcoma protuberans.

D2-40

Podoplanin antibody that highlights lymphatic endothelium and aids in identifying lymphatic invasion and vascular tumors.

BRAF V600E

Common activating mutation in melanoma detected by molecular testing to guide selection of targeted kinase inhibitor therapy.

TCR gene rearrangement

Molecular test assessing clonality of T-cell receptor genes to support diagnosis of cutaneous T-cell lymphoma.

PAS stain

Periodic acid-Schiff histochemical stain that highlights fungal cell walls, basement membranes, and glycogen in tissue sections.

Ber-EP4

Immunohistochemical marker positive in basal cell carcinoma and negative in most squamous cell carcinomas, aiding their distinction.

Neutral buffered formalin

Ten percent formaldehyde solution used for tissue fixation, typically at a 10:1 ratio of fixative to tissue volume.

Turnaround time

Interval from specimen accession to report sign-out, monitored as a laboratory quality indicator and performance metric.

Proficiency testing

External program in which laboratories test unknown samples and results are compared to peers to verify analytic performance.

Frozen section

Rapid intraoperative tissue preparation used for margin or diagnosis assessment, with lower accuracy than permanent sections.

CLIA

Federal law establishing laboratory testing standards including personnel qualifications, quality control, and proficiency testing requirements.

Second-opinion review

Independent review of slides and reports by another pathologist to confirm or revise a diagnosis before treatment decisions.

Clinicopathologic correlation

Integration of histologic findings with clinical history, examination, and imaging to reach an accurate diagnosis and management plan.