General Pathology Laboratory Review

Vocabulary practice flashcards covering endocrine, renal, dermatologic, musculoskeletal, and central nervous system histopathology from the laboratory review lecture.

Multinodular Goitre

A non-neoplastic enlargement of the thyroid gland characterized histologically by vague nodules composed of macrofollicles with abundant colloid, lined by cuboidal follicular epithelium, and accompanied by areas of haemorrhage.

Hashimoto Thyroiditis

An autoimmune thyroid disorder characterized microscopically by extensive lymphocytic infiltrates forming lymphoid follicles with germinal centres, interstitial fibrosis, and atrophic residual follicles showing oncocytic change.

Hürthle Cell (Oncocytic) Change

Transformed thyroid follicular epithelial cells that develop abundant, granular, eosinophilic cytoplasm packed with mitochondria, characteristically lining the atrophic follicles in Hashimoto thyroiditis.

Graves Disease

A form of hyperthyroidism characterized histologically by large, irregularly shaped follicles with pseudo-papillary infoldings lacking true fibrovascular cores, columnar follicular cells, and scalloping of marginal colloid representing resorption.

Orphan Annie Eye Nuclei

Optically clear, empty-appearing, ground-glass nuclei characteristic of papillary thyroid carcinoma.

Psammoma Bodies

Concentric, laminated, basophilic calcospherites characteristic of papillary thyroid carcinoma and psammomatous meningiomas.

Follicular Adenoma

A benign, encapsulated, well-circumscribed thyroid nodule that compresses the adjacent normal thyroid parenchyma, defined by an intact fibrous capsule with no capsular or vascular invasion.

Follicular Carcinoma

A malignant follicular neoplasm comprising microfollicles with small, uniform nuclei, speckled chromatin, and colloid, whose definitive diagnosis requires demonstrating capsular or vascular invasion beyond the tumor capsule.

Medullary Thyroid Carcinoma

A neuroendocrine tumor originating from C cells, characterized by nests or islands of polygonal cells with stippled 'salt and pepper' chromatin, retraction artifacts, and amyloid deposits displaying salmon-pink staining and apple-green birefringence under polarized light.

Pituitary Adenoma

A relatively well-circumscribed sellar neoplasm with an incomplete capsule, characterized by a trabecular architecture, a rich vascular network, and uniform cells with round nuclei and granular chromatin.

Craniopharyngioma (Papillary Type)

A benign sellar neoplasm resembling squamous papilloma, composed of branching fibrovascular stromal cores lined by bland stratified squamous epithelium without wet keratin or stellate reticulum.

Craniopharyngioma (Adamantinomatous Type)

A sellar neoplasm occurring predominantly in children, displaying islands of epithelium with peripheral nuclear palisading, loose central areas mimicking dental stellate reticulum, wet keratin, cystic degeneration, and gross 'machine oil' fluid.

Adrenocortical Adenoma

A benign adrenocortical neoplasm presenting as a well-circumscribed nodule without hemorrhage or necrosis, microscopically composed of nests of cells with small nuclei and abundant pale, lipid-rich cytoplasm.

Pheochromocytoma

A neoplasm of adrenal medullary chromaffin cells that compresses the cortex, characterized histologically by nests, trabeculae, or sheets of polygonal cells with ovoid nuclei, stippled chromatin, and frequent hemorrhage.

Zellballen

The distinctive nested or ball-like architectural cluster of polygonal chromaffin cells surrounded by a rich vascular network in pheochromocytoma.

Neuroblastoma

A pediatric malignant adrenal or sympathetic tumor characterized by sheets and nests of immature-looking small round blue cells with stippled chromatin, areas of necrosis, and Homer-Wright pseudorosettes.

Insulinitis

Inflammatory infiltration of pancreatic islets of Langerhans dominated by lymphocytes, characteristic of early Type $1$ diabetes mellitus.

Islet Amyloidosis

Extracellular amyloid deposition within the pancreatic islets of Langerhans, displaying apple-green birefringence under polarized light with Congo red stain, typical of Type $2$ diabetes mellitus.

Thyroidization of Tubules

A microscopic feature of chronic pyelonephritis where atrophied renal tubules dilate and become filled with dense, eosinophilic colloid-like secretions, closely mimicking thyroid follicles.

Chronic Pyelonephritis

A chronic tubulointerstitial renal disease characterized by chronic inflammatory cell infiltrates in the interstitium, periglomerular fibrosis, glomerular hyalinization/sclerosis, and tubular thyroidization.

Renal Infarct

A wedge-shaped ischemic cortical lesion resulting from arterial embolism, defined microscopically by coagulative necrosis with absent nuclei, preserved architectural outlines, and intraluminal cellular debris.

Clear Cell Renal Cell Carcinoma

A malignant kidney neoplasm arising from proximal convoluted tubule epithelium, associated with loss of $VHL$ protein function and characterized by nested architecture of cells with low $\text{N:C}$ ratios and abundant glycogen- and lipid-rich clear cytoplasm.

Nephroblastoma (Wilms Tumor)

A malignant pediatric renal neoplasm classically presenting with a triphasic histologic composition: undifferentiated blastema (small round blue cells), epithelial elements (primitive tubules/glands), and fibrous stroma.

Dysplastic Nevus

An acquired atypical pigmented skin mole with irregular margins and variegated color, showing architectural disorder and disorganized melanocyte placement, indicating an increased risk of melanoma.

Nodular Melanoma

An invasive cutaneous melanoma subtype exhibiting prominent vertical downward growth into the dermis, prominent nucleoli, intracytoplasmic brown melanin pigment, and frequent atypical mitotic figures.

Keratin Pearl

A concentric, laminated whorl of abnormal keratinized squamous cells situated within nests of well-differentiated invasive squamous cell carcinoma.

Cutaneous Squamous Cell Carcinoma

A malignant cutaneous epithelial neoplasm arising from the epidermis, characterized by invasive pleomorphic squamous cells with abundant eosinophilic cytoplasm, prominent intercellular bridges, and abnormal mitoses.

Rodent Ulcer

The clinical descriptive term for an ulcerated, locally destructive basal cell carcinoma characterized by rolled pearly borders.

Peripheral Palisading

The ordered, parallel alignment of elongated basaloid cell nuclei at the periphery of tumor nests, reminiscent of a picket fence, characteristic of basal cell carcinoma.

Basal Cell Carcinoma

A locally invasive cutaneous epithelial neoplasm composed of nests of basaloid cells with scant cytoplasm and hyperchromatic nuclei, peripheral palisading, peritumoral clefting, and a surrounding myxoid stroma.

Munro Microabscesses

Microscopic accumulations of neutrophils within parakeratotic mounds in the stratum corneum, diagnostic of active psoriasis.

Spongiosiform Pustules of Kogoj

Intraepidermal collections of neutrophils located within the stratum spinosum, characteristic of psoriasis.

Acantholysis

The loss of intercellular connections (desmosomes) between keratinocytes, leading to intraepidermal blister formation in pemphigus vulgaris.

Pemphigus Vulgaris

An autoimmune blistering disease characterized clinically by flaccid skin bullae and painful oral mucosal erosions, mediated by acantholysis and an intraepidermal split.

Bullous Pemphigoid

An autoimmune skin condition featuring tense fluid-filled blisters produced by a subepidermal split at the dermoepidermal junction without acantholysis.

Henderson-Patterson Bodies

Large, intracytoplasmic viral inclusion bodies characteristic of molluscum contagiosum (MCV1), which appear eosinophilic in early stages and shift to a basophilic hue as they mature.

Molluscum Contagiosum

A viral infection caused by Molluscum Contagiosum Virus Type $1$ ($\text{MCV1}$) that produces dome-shaped, firm, umbilicated papules containing characteristic molluscum bodies.

Koilocytes

Epithelial cells infected with human papillomavirus (HPV) showing marked acanthosis, hyperkeratosis, wrinkled hyperchromatic nuclei, and clear perinuclear halos.

Gouty Tophus

A nodular mass composed of aggregates of needle-shaped monosodium urate crystals surrounded by foreign body multinucleated giant cells and chronic inflammatory infiltrates.

Osteogenesis Imperfecta (Brittle Bone Disease)

An autosomal dominant disorder caused by mutations in alpha $1$ and alpha $2$ chains of Type $1$ collagen, resulting in defective bone matrix, skeletal fragility, blue sclerae, hearing loss, and dental imperfections.

Leiomyoma

A benign smooth muscle tumor presenting grossly as a firm, tan-white, whorled nodule and microscopically as interlacing fascicles of spindle cells with uniform cigar-shaped nuclei with blunt ends.

Lipoma

A benign, well-circumscribed adipocytic tumor composed of lobules of mature adipocytes separated by thin fibrous septa, possessing small, eccentrically placed, compressed nuclei.

Pyogenic Osteomyelitis

A bacterial infection of bone and bone marrow, most commonly caused by Staphylococcus aureus ($80\%$ to $90\%$ of culture-positive cases), acquired via hematogenous seeding, contiguous extension, or direct implantation.

Codman Triangle

A radiologic triangular shadow created when an aggressive bone tumor elevates the periosteum away from the cortical bone surface, classic for osteosarcoma.

Osteosarcoma

The most common primary non-hematopoietic bone malignancy, defined microscopically by malignant sarcomatous tumor cells that directly lay down unmineralized bone matrix (osteoid).

Postmenopausal Osteoporosis (Type 1)

A metabolic bone disease affecting approximately $40\%$ of postmenopausal women, initiated by estrogen deficiency, leading to elevated $\text{IL-1}$, $\text{IL-6}$, and $\text{TNF}$ levels, increased $\text{RANK/RANKL}$ expression, and marked osteoclast-mediated bone resorption.

Senile Osteoporosis (Type 2)

Age-related bone loss attributed to reduced replicative activity of osteoprogenitor cells, decreased synthetic activity of osteoblasts, and reduced biologic activity of matrix-bound growth factors.

Nodular Fasciitis

A benign, self-limiting myofibroblastic proliferation arising in deep dermis, subcutis, or fascia, harboring a $t(17;22)$ translocation producing an $MYH9\text{-}USP6$ gene fusion and displaying loose fascicles of spindle cells in a tissue culture-like pattern.

Purulent Meningitis

Acute bacterial inflammation of the leptomeninges characterized histologically by dense infiltrates of neutrophils filling the subarachnoid space.

Tuberculoma

A circumscribed CNS lesion characterized histologically by central caseous necrosis enclosed by epithelioid histiocytes, Langhans multinucleated giant cells, and lymphocytes.

Cerebral Paragonimiasis

A parasitic infection of the central nervous system caused by Paragonimus species, recognized on tissue sections by operculated trematode eggs surrounded by a brisk granulomatous reaction.

Neurocysticercosis

A CNS infection caused by the larval form of Taenia solium, characterized histologically by an invaginated nonviable scolex within a viable cystic wall bearing outer microvilli.

Astrocytoma

A glial neoplasm characterized by proliferation of atypical astrocytes with enlarged pleomorphic nuclei against a fibrillary background; high-grade tumors are distinguished by mitoses and necrosis.

Pseudo-palisading Necrosis

A classic microscopic feature of glioblastoma multiforme characterized by dense cellular ribbons of tumor cells crowding and aligning around serpentine zones of ischemic necrosis.

Oligodendroglioma

A primary glial brain tumor composed of uniform cells with rounded central nuclei surrounded by clear perinuclear halos ('fried egg' appearance) and secondary structures of Scherer.

Meningioma

A predominantly benign, dural-based intracranial neoplasm composed of syncytial sheets of meningothelial cells forming concentric whorls, psammoma bodies, and nuclei with pseudoinclusions.