Dermatopathology

Dermatopathology Indian Medical PG Question 1: What is the primary condition for which calcitriol is used as a treatment?

• A. Pemphigus
• B. Secondary hyperparathyroidism (Correct Answer)
• C. Lichen planus
• D. Leprosy

Dermatopathology Explanation: Secondary hyperparathyroidism - Calcitriol is the active form of vitamin D (1,25-dihydroxyvitamin D₃), and it is crucial for regulating calcium and phosphate levels in the body [1]. - In secondary hyperparathyroidism, often seen in chronic kidney disease (CKD), the kidneys cannot convert vitamin D to its active form, leading to hypocalcemia and increased PTH secretion [1], [2]. - Calcitriol supplementation helps to increase calcium absorption from the gut and suppress the release of parathyroid hormone (PTH), thereby treating the underlying cause of secondary hyperparathyroidism [1], [2]. - This is the primary therapeutic indication for calcitriol in clinical practice. Lichen planus - This is a chronic inflammatory condition affecting the skin, hair, nails, and mucous membranes - Typically treated with corticosteroids or other immunosuppressants - Calcitriol has no primary role in the treatment of lichen planus; its therapeutic applications are predominantly related to calcium and bone metabolism Pemphigus - Pemphigus is a group of rare autoimmune blistering diseases that affect the skin and mucous membranes - Primary treatment involves immunosuppressants like corticosteroids, often in high doses - Calcitriol is not indicated for the treatment of pemphigus, as its mechanism of action is unrelated to the autoimmune processes characteristic of this disease Leprosy - Leprosy is a chronic infectious disease caused by the bacterium Mycobacterium leprae - Treated with multi-drug therapy (MDT), which includes antibiotics like rifampicin, dapsone, and clofazimine - Calcitriol is not an antibiotic and therefore has no role in treating the bacterial infection responsible for leprosy

Dermatopathology Indian Medical PG Question 2: A 30-year-old woman presents with flaccid bullae on her skin that are easy to rupture. A biopsy of the lesion reveals a suprabasal split. What is the most likely diagnosis?

• A. Erythema multiforme
• B. Pemphigus vegetans
• C. Pemphigus vulgaris (Correct Answer)
• D. Pemphigus foliaceous

Dermatopathology Explanation: ***Pemphigus vulgaris*** - Characterized by **flaccid bullae** that are easily ruptured, and a classic histological finding of a **suprabasal split** in the epidermis, indicating acantholysis just above the basal layer. - Mucosal involvement is common, and the positive **Nikolsky sign** (epidermal detachment with lateral pressure) is often present, which is typical for pemphigus vulgaris due to the superficial nature of the blistering. - The combination of **flaccid bullae + suprabasal split** is pathognomonic for pemphigus vulgaris. *Erythema multiforme* - Typically presents with **targetoid lesions** (concentric rings of erythema) and is often associated with infections, particularly herpes simplex virus (HSV). - Histologically, it shows **interface dermatitis** with vacuolar degeneration of basal cells and scattered necrotic keratinocytes, not a suprabasal split or acantholysis. *Pemphigus vegetans* - A rare variant of pemphigus vulgaris, it presents with **vegetating plaques** in intertriginous areas (axillae, groin), which are eroded but not primarily flaccid bullae covering wide areas. - While it also involves a suprabasal split at the same level as pemphigus vulgaris, the clinical presentation of vegetating plaques rather than widespread flaccid bullae helps differentiate it. *Pemphigus foliaceous* - This autoimmune blistering disease features very **superficial bullae** that rupture so easily they typically present as erosions, crusts, and scaling rather than intact blisters. - Histologically, it shows a **subcorneal or granular layer split** (more superficial than pemphigus vulgaris), not the deeper suprabasal split seen in this patient's biopsy. - Mucosal involvement is **rare** in pemphigus foliaceous, unlike pemphigus vulgaris.

Dermatopathology Indian Medical PG Question 3: A 45-year-old man presents with the following skin changes (as shown in the image). What relevant history should be taken to diagnose this condition?

• A. Dementia
• B. History of dietary pattern, dementia, and diarrhea (Correct Answer)
• C. Dietary history
• D. Depression

Dermatopathology Explanation: ***History of dietary pattern, dementia, and diarrhea*** - The image displays skin changes consistent with a "Casal's necklace" pattern, characteristic of **pellagra**, a disease caused by **niacin (Vitamin B3) deficiency**. - Pellagra is classically associated with the "3 Ds": **dermatitis** (the observed skin changes), **diarrhea**, and **dementia**. A comprehensive history should therefore include questions about dietary patterns (especially corn-based diets lacking tryptophan and niacin), gastrointestinal symptoms like diarrhea, and neurological/psychiatric symptoms indicative of dementia. *Dementia* - While **dementia** is one of the classic "3 Ds" of pellagra (niacin deficiency), it is only one component of the presentation and insufficient on its own to guide a complete diagnostic history for this condition. - Focusing solely on dementia would miss crucial aspects like dietary intake and gastrointestinal symptoms that are integral to diagnosing pellagra. *Dietary history* - A **dietary history** is indeed very relevant for diagnosing pellagra, as it helps identify potential niacin deficiency, commonly associated with diets heavily reliant on corn without proper preparation. - However, pellagra is not only characterized by dermatological signs and dietary insufficiency but also by gastrointestinal and neurological symptoms. Limiting the history to diet alone would therefore be incomplete. *Depression* - **Depression** can be a symptom of various nutritional deficiencies and other medical conditions, but it is not one of the classic "3 Ds" of pellagra, which are dermatitis, diarrhea, and dementia. - While mood changes might be present in some patients with niacin deficiency, focusing solely on depression would not encompass the full clinical picture of pellagra and could lead to misdiagnosis.

Dermatopathology Indian Medical PG Question 4: A 70-year-old man comes to the emergency department because of a skin rash and severe itching. He appears ill; there is a generalized skin rash that is scaly, erythematous, and thickened. His palms, soles, and scalp are also involved. Which of the following is the most likely diagnosis?

• A. erythroderma (exfoliative dermatitis) (Correct Answer)
• B. pemphigus vulgaris
• C. dermatitis herpetiformis
• D. rosacea

Dermatopathology Explanation: ***erythroderma (exfoliative dermatitis)*** - Erythroderma is characterized by a **generalized erythematous (red), scaly, and thickened skin rash** covering more than 90% of the body surface, accompanied by **severe itching**. - This condition is often associated with a **systemic illness**, and the patient's description of "appears ill" further supports this diagnosis. *pemphigus vulgaris* - Pemphigus vulgaris typically presents with **flaccid blisters** and erosions, particularly affecting mucous membranes, which are not described here. - While it can be widespread, the primary lesion is a **blister** rather than diffuse erythema and scaling. *dermatitis herpetiformis* - Dermatitis herpetiformis is characterized by intensely **pruritic (itchy) papules and vesicles** typically found on the extensor surfaces (e.g., elbows, knees, buttocks). - It is strongly associated with **celiac disease** and does not present as a generalized scaly, erythematous thickening. *rosacea* - Rosacea primarily affects the **face**, causing **erythema**, flushing, papules, and pustules, often sparing the palms, soles, and scalp. - It is not characterized by generalized scaling, thickening, or severe itching over the entire body.

Dermatopathology Indian Medical PG Question 5: In Erythrodermic psoriasis, _____ or more of body surface area is involved

• A. 90% (Correct Answer)
• B. 85%
• C. 95%
• D. 80%

Dermatopathology Explanation: ***90%*** - Erythrodermic psoriasis is defined by the involvement of **90% or more of the total body surface area** with erythema and scaling. - This extensive skin involvement leads to significant systemic symptoms and is considered a **medical emergency**. - It represents the most severe form of psoriasis with near-complete body involvement. *85%* - While representing extensive involvement, **85%** does not meet the diagnostic threshold for erythrodermic psoriasis. - The definition specifically requires **≥90%** body surface area involvement. *95%* - Although **95%** body surface area involvement would certainly qualify as erythrodermic psoriasis, it exceeds the minimum diagnostic threshold. - The defining cutoff is **90% or more**, not 95%. *80%* - Involvement of **80%** of the body surface area, while extensive, does not meet the criteria for erythrodermic psoriasis. - This would typically be classified as **severe plaque psoriasis** rather than erythrodermic form.

Dermatopathology Indian Medical PG Question 6: Identify the diagnosis based on the dermatology immunofluorescence (IF) image provided.

• A. Pemphigus vulgaris
• B. Pemphigus foliaceus
• C. Bullous pemphigoid
• D. Dermatitis herpetiformis (Correct Answer)

Dermatopathology Explanation: ***Dermatitis herpetiformis*** - The immunofluorescence image shows **granular IgA deposits** at the **dermal papillae region**, which is characteristic of dermatitis herpetiformis. - This condition is strongly associated with **celiac disease** and presents with intensely pruritic papules and vesicles. *Pemphigus vulgaris* - Immunofluorescence in pemphigus vulgaris typically shows a **fishnet pattern** of IgG deposits throughout the **epidermis**, reflecting antibodies against desmoglein 3 and 1. - This pattern is an intercellular deposition, not granular at the dermal papillae. *Pemphigus foliaceus* - Similar to pemphigus vulgaris, pemphigus foliaceus also exhibits **intercellular IgG deposits** in the epidermis, but it is usually more superficial, targeting desmoglein 1. - The image does not show this intercellular epidermal staining. *Bullous pemphigoid* - Bullous pemphigoid is characterized by **linear IgG and C3 deposits along the dermal-epidermal junction** (basement membrane zone). - The image distinctly shows granular IgA, not linear IgG/C3, and specifically in the dermal papillae.

Dermatopathology Indian Medical PG Question 7: The following is a post-orchidectomy histopathological specimen. Diagnosis is:

• A. Seminoma (Correct Answer)
• B. Teratoma
• C. Lymphoma
• D. Yolk sac tumor

Dermatopathology Explanation: ***Seminoma*** - The image shows a **monotonous population of large, clear cells** with prominent nucleoli and distinct cell borders, arranged in lobules separated by fibrous septa with **lymphocytic infiltration** [1]. - This classic histological appearance, along with the presence of **syncytiotrophoblasts** (though not explicitly mentioned as a key feature for diagnosis from this image alone, it can be seen in some seminomas), is characteristic of **seminoma**, the most common germ cell tumor of the testis [1]. *Teratoma* - Teratomas are characterized by the presence of **multiple germ layers** (ectoderm, mesoderm, endoderm) with various differentiated tissues like cartilage, bone, neural tissue, or glandular structures [1]. - The image does not show the **heterogeneous tissue differentiation** typical of a teratoma. *Lymphoma* - Testicular lymphoma typically presents with a **diffuse infiltrate of atypical lymphoid cells**, often with a high mitotic rate, and lacks the clear cell appearance and fibrous septa seen in the image. - It is more common in **older men** and can be bilateral, unlike the typical presentation of seminoma. *Yolk sac tumor* - Yolk sac tumors (endodermal sinus tumors) are characterized by various architectural patterns, including **reticular, microcystic, solid, and papillary**, often with **Schiller-Duval bodies** (glomeruloid structures) [1]. - The image does not display these specific patterns or the characteristic Schiller-Duval bodies. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lower Urinary Tract and Male Genital System, pp. 979-982.

Dermatopathology Indian Medical PG Question 8: Renal cell carcinoma is characterized by which of the following histopathological features?

• A. Clear cell morphology with abundant cytoplasm (Correct Answer)
• B. Nested/alveolar growth pattern
• C. High nuclear grade with prominent nucleoli
• D. Rich capillary network

Dermatopathology Explanation: ***Invades Renal Vein*** - **Renal cell carcinoma** is known for **venous invasion**, particularly involving the renal vein, which can lead to **thrombus formation** [1][2]. - This feature is significant for staging and prognosis, often indicating **advanced disease** [2]. *Hematuria usually absent* - **Hematuria** is often present in renal cell carcinoma, contrary to this assertion. - The presence of **blood in urine** is a common symptom that can raise suspicion for malignancy. *Arises from proximal convoluted tubule* - While renal cell carcinoma originates from the **epithelial cells**, it primarily arises from the **proximal tubule**, but this option lacks the specificity related to its histopathology. - More accurately, the clear cell type is the most common variant associated with this tumor [1]. *More common in females* - Renal cell carcinoma is actually more prevalent in **males**, contradicting this statement. - The male-to-female ratio is approximately **2:1**, making it less common in females. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 959-961. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 492-493.

Dermatopathology Indian Medical PG Question 9: All are true about the marking X in histopathological specimen from a patient of fatty liver except:

• A. Eosinophilic aggregates of prekeratin
• B. Intranuclear inclusions (Correct Answer)
• C. Best visualized with masson trichrome
• D. Also seen in Indian childhood cirrhosis

Dermatopathology Explanation: ***Best visualized with masson trichrome*** - The marking 'X' refers to **Mallory bodies** (also known as Mallory's hyaline or alcoholic hyaline) [1]. - Mallory bodies are **eosinophilic cytoplasmic inclusions** and are best visualized with **hematoxylin and eosin (H&E) stain**, not Masson trichrome. Masson trichrome is used to highlight **collagen** (fibrosis) [2]. *Eosinophilic aggregates of prekeratin* - Mallory bodies are indeed **eosinophilic aggregates** composed primarily of **intermediate filaments**, including **prekeratin** (cytokeratin 8 and 18) [3]. - This description accurately characterizes the composition and staining properties of Mallory bodies. *Intranuclear inclusions* - Mallory bodies are **cytoplasmic inclusions**, not intranuclear [1][3]. - Intranuclear inclusions are typically associated with viral infections (e.g., CMV, herpes) or certain genetic disorders. *Also seen in Indian childhood cirrhosis* - Mallory bodies are a characteristic feature of **alcoholic liver disease** but can also be found in other conditions, including **non-alcoholic steatohepatitis (NASH)**, **Wilson's disease**, **cholestasis**, and **Indian childhood cirrhosis** [1]. - Their presence in Indian childhood cirrhosis is a known histopathological finding. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 388-389. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, pp. 848-850. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Liver and Gallbladder, p. 852.

Dermatopathology Indian Medical PG Question 10: A patient presents with intermittent fever, no weight loss and enlarged retroperitoneal lymph nodes. Peripheral smear is normal. Gross sample and its histopathology slide is shown below. Comment on the diagnosis.

• A. Non-Hodgkin's lymphoma
• B. Castleman disease (Correct Answer)
• C. Angiolymphoid hyperplasia
• D. IgG4 related disease

Dermatopathology Explanation: ***Castleman disease*** - The image shows **"lollipop lesions"** or **"onion-skinning"** of follicles with **regressed germinal centers** and prominent mantle zones, characteristic of the hyaline-vascular variant of Castleman disease. - Clinical features like **intermittent fever** and **enlarged retroperitoneal lymph nodes** with **no weight loss** can be seen in Castleman disease, particularly the unicentric type. *Non-Hodgkin's lymphoma* - This would typically show effacement of the normal lymph node architecture by a **monotonous proliferation of atypical lymphocytes**. - While it can cause lymphadenopathy and fever, the specific histological features presented do not align with typical non-Hodgkin's lymphoma. *Angiolymphoid hyperplasia* - Characterized by **multiple vascular channels** lined by plump endothelial cells with **lymphoid infiltrates**. - It often presents as subcutaneous nodules, usually in the head and neck region, and lacks the follicular changes seen here. *IgG4 related disease* - Histologically, this disease is characterized by a **dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells**, storiform fibrosis, and obliterative phlebitis. - While it can cause lymph node enlargement, the specific follicular changes in the image are not typical of IgG4-related disease.

Dermatopathology Flashcard 1 of 10

Question: _____ may be associated with Munro microabscesses, which are collections of neutrophils in the stratum corneum

Answer: Psoriasis

Dermatopathology Flashcard 2 of 10

Question: _____ relates to process of abnormal epidermal cell keratinization.

Answer: Dyskeratosis

Dermatopathology Flashcard 3 of 10

Question: _____keratosis is characterized by nuclear pyknosis and condensation of the cytoplasm of keratinocytes.

Answer: Dys

Dermatopathology Flashcard 4 of 10

Question: DNA analysis of person with fine scaly erythematous plaques, showing clonal arrangements of T cell receptor genes, is suggestive of _____

Answer: mycosis fungoides

Dermatopathology Flashcard 5 of 10

Question: Which layer is involved in blister formation in a superficial partial thickness burn?_____

Answer: Papillary dermis

Dermatopathology Flashcard 6 of 10

Question: Bullous pemphigoid presents with a subepidermal blister with an _____ rich infiltrate

Answer: eosinophil

Dermatopathology Flashcard 7 of 10

Question: What type of nevus shows lymphocytic infiltration surrounding nevus cells? _____

Answer: Halo nevus

Dermatopathology Flashcard 8 of 10

Question: _____ has a characteristic histopathology of "Claw clutching a Ball' appearance

Answer: Lichen nitidus

Dermatopathology Flashcard 9 of 10

Question: _____ giant cells are lipid-containing macrophages, having a central ring of nuclei while the peripheral cytoplasm is clear due to accumulated lipid

Answer: Touton

Dermatopathology Flashcard 10 of 10

Question: Upward elongation of the dermal papillae, giving an accentuated and sometimes irregular, undulating configuration to the dermal–epidermal junction is known as _____

Answer: papillomatosis