Pathology: AIIMS MAY 2011

Q-1. Commonest histological finding in benign hypertension is
a) Proliferative endarteritis
b) Necrotizing arteriolitis
c) Hyaline arteriosclerosis
d) Cystic medial necrosis

Answer: Hyaline arteriosclerosis
Explanation:
In benign hypertension:
Hyaline arteriosclerosis- Hyaline thickening of the walls of arterioles with loss of underlying structural details and with narrowing of the lumen
In malignant hypertension:
Necrotizing arteriolitis-Deposition of fibrinoid and acute necrosis of the vessel walls

Q-2. A 45 years old male had severe chest pain and was admitted to the hospital with a diagnosis of acute myocardial infarction. Four days later he died and autopsy showed trans-mural coagulative necrosis. Which of the following microscopic features will be seen on further examination?
a) Fibroblasts and collagen
b) Granulation tissue
c) Neutrophilic infiltration surrounding coagulative necrosis
d) Granulomatous inflammation

Answer: Neutrophilic infiltration surrounding coagulative necrosis
Explanation:
Morphological changes in Myocardial infarction: Time and microscopic finding
Half hour to 4 hours:
Variable waviness of fibres at border
4-12 hours:
Beginning of coagulative necrosis
Edema
Hemorrhage
12-24 hours:
Ongoing coagulative necrosis
Beginning neutrophil infiltration
1-3 days:
Coagulative necrosis with loss of nuclei and striations
Interstitial infiltrate of neutrophils

Q-3. A 7 yrs old girl is brought with complaints of generalized swelling of the body. Urinary examination reveals grads 3 proteinuria and the presence of hyaline and fatty casts. She has no history of hematuria. Which of the following statements about her condition is true?
a) No IgG deposits or C3 deposition on renal biopsy
b) Her C3 levels will be low
c) IgA nephropathy is the likely diagnosis
d) Alport’s syndrome is the likely diagnosis

Answer: No IgG deposits or C3 deposition on renal biopsy
Explanation:
Nephrotic syndrome:
Massive proteinuria
Hypo-albuminemia
Generalized edema
Hyperlipidemia and lipiduria
Important points:
The most important of primary glomerular lesions are minimal changes disease, membranous glomerulonephritis and focal segmental glomerulo-sclerosis.
The most frequent systemic causes are diabetes, amyloidosis and SLE.

Q-4. Infra-clavicular lesion of tuberculosis is known as
a) Gohn’s focus
b) Puhl’s focus
c) Assman’s focus
d) Simon’s focus

Answer: Assman’s focus
Explanation:
Pulmonary infection is usually evident as sub-pleural tubercle- Primary or Ghon’s focus
Ghon’s complex is a lesion seen in the lung that is caused by tuberculosis.
The lesions consist of a calcified focus of infection and an associated lymph node.
Commonest site of isolated lesion of chronic pulmonary tuberculosis is apex of lung (Puhl’s lesion), because the blood flow is sluggish at the apex and diffusion is poor.
Infra-clavicular lesion of chronic pulmonary tuberculosis- Assman’s focus
A Simon focus is a tuberculosis (TB) nodule that can form in the apex of the lung when a primary TB infection elsewhere in the body spreads to the lung apex via the bloodstream.
Simon focus nodules are often calcified.

Q-5. CD4+ is not important for which of the following
a) Antibody production
b) Cytotoxicity of T cells
c) Memory B cells
d) Opsonisation

Answer: Cytotoxicity of T cells (?)
Explanation:
CD4 is expressed on approximately 60 % of mature CD3+ T cells whereas CD8 is expressed on about 30 % of T cells.
These T cell membrane associated glycoproteins serve as co-receptor in T cell activation.
During antigen presentation, CD4 molecules bind to class II MHC molecules expressed on antigen presenting cells.
In contrast, CD8 molecules bind to class I MHC molecules.
CD8+ T cell function mainly as cytotoxic cells to kill other cells but also secrete IL2 and interferon gamma like TH1 type
CD4+ T cells influence the function of virtually all other cells of immune system, including other T cells, B cells, macrophages and NK cells.
TH1 subset secretes IL2 and interferon gamma and TH2 subset secrets IL-4 and IL-5.
TH1 subset is involved in facilitating delayed hypersensitivity, macrophage activation and synthesis of opsonizing and complement fixing antibodies; such as IgG2a in mice.
TH2 subset aids in the synthesis of other class of antibodies notably IgE and in activation of eosinophils.

Q-6. What does cardiac polyp means?
a) Acute infarct
b) Cardiac aneurysm
c) Benign tumor
d) Fibrinous clot

Answer: Fibrinous clot
Explanation:
Postmortem fibrinous clots in heart are known as cardiac polyp.
Agonal thrombi: In case of a person dying slowly with circulatory failure, a firm, stringy, tough, pale yellow thrombus forms in the cavities, usually on the right side of heart.
Black currant jelly- When blood clots rapidly, a soft, lumpy, uniformly, dark red, slippery, moist clot is produced.
Chicken fat: When blood clots slowly, a pale or bright yellow of layer of serum and fibrin (Chicken fat) is seen above black currant jelly.

Q-7. In congenital dystrophic variety of epidermolysis bullosa mutation is seen in the gene coding for
a) Laminin 4
b) Collagen type 7
c) Alpha 6 integerin
d) Keratin 14

Answer: Collagen type 7
Explanation:
Epidermolysis bullosa is a group of inherited bullous disorders characterized by blister formation in response to mechanical trauma.
Epidermolysis bullosa is classified into 3 major categories.
Epidermolysis bullosa simplex:
Intra-epidermal skin separation
Mutation in the genes encoding keratin 14 and 5
Junctional epidermolysis bullosa:
Skin separation in lamina lucida
Dystrophic epidermolysis bullosa:
Sub-lamina densa skin separation
Mutation in the COL 7A1 gene encoding type VII collagen