Skin Lesions: Morphology and Description — MCQs
Elderly man with a long-standing mole on his face that is increasing in size and showing an irregular border. Diagnosis:
A 30-year-old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is:
Identify the type of skin lesion shown in the image.
A child presents with grouped vesicles on the lips. What is the bedside investigation that you would like to do?
A 45-year-old Ulcerative colitis patient presents with multiple painful lesions on both legs. What is the diagnosis?
Comment on the image shown:
A 24-year-old male presents with a lesion at the site shown in the image for 4 years. He says it has increased in thickness over the years. Diagnosis is:
Identify the skin condition depicted in the image.
Dyskeratosis refers to which of the following?
A patient presents with orange-hued skin lesions and hyperkeratotic palms and soles. A biopsy shows alternating parakeratosis and orthokeratosis. What is the most likely diagnosis?
Skin Lesions: Morphology and Description Indian Medical PG Practice Questions and MCQs
Question 1: Elderly man with a long-standing mole on his face that is increasing in size and showing an irregular border. Diagnosis:
- A. Superficial spreading melanoma
- B. Nodular melanoma
- C. Acral melanoma
- D. Lentigo maligna (Correct Answer)
Explanation: ***Lentigo maligna*** - This type of melanoma commonly affects **elderly individuals** and presents as a **slowly enlarging, irregularly bordered, flat or slightly raised pigmented lesion** on sun-exposed areas like the face. - It often has a **long radial growth phase** before progressing to invasive lentigo maligna melanoma. *Superficial spreading melanoma* - While common, it typically presents on the **trunk or extremities** and has a faster growth rate compared to lentigo maligna. - It often appears as a **flat, asymmetrical lesion with varied colors and irregular borders**, but the age and location details point away from this. *Nodular melanoma* - This is an **aggressive form** that grows vertically from the start, presenting as a **dark, raised, often ulcerated nodule** and typically has a shorter history of rapid growth. - It lacks the characteristic long-standing, flat growth pattern described in the elderly patient's face. *Acral melanoma* - This rare type occurs on the **palms, soles, or under the nails (subungual)**, not typically on the face. - It often appears as a **pigmented streak or patch** in these acral locations.
Question 2: A 30-year-old male presented with silvery scales on elbow and knee, that bleed on removal. The probable diagnosis is:
- A. Secondary syphilis
- B. Psoriasis (Correct Answer)
- C. Pityriasis
- D. Seborrhoeic dermatitis
Explanation: ***Psoriasis*** - The presence of **silvery scales** on the elbows and knees, which **bleed upon removal** (Auspitz sign), is a classic presentation of **plaque psoriasis**. - Psoriasis is a chronic inflammatory skin condition characterized by **accelerated epidermal turnover**. *Secondary syphilis* - Secondary syphilis typically presents with a **generalized maculopapular rash**, which can affect the palms and soles, but it does not usually feature silvery scales or the Auspitz sign. - Other common symptoms of secondary syphilis include **fever, lymphadenopathy, and condyloma lata**. *Pityriasis* - **Pityriasis rosea** is characterized by an oval, fawn-colored, scaly rash, often preceded by a **herald patch**, and usually resolves spontaneously. It does not typically present with silvery scales or bleeding on removal. - **Pityriasis versicolor** is caused by yeast and presents as hypopigmented or hyperpigmented macules with fine scales, commonly on the trunk, not silvery scales on elbows and knees. *Seborrhoeic dermatitis* - Seborrhoeic dermatitis involves greasy, yellowish scales on red skin, typically affecting areas rich in sebaceous glands like the scalp, face (nasolabial folds, eyebrows), and chest. - It does not present with silvery scales or the Auspitz sign, which are specific to psoriasis.
Question 3: Identify the type of skin lesion shown in the image.
- A. Papule
- B. Patch
- C. Nodule
- D. Macule (Correct Answer)
Explanation: ***Macule*** - The lesion shown is a **macule**, characterized by being **flat and circumscribed** with no elevation above the skin surface. - A macule is defined as a **skin discoloration less than 1 cm in diameter** without any palpable change in texture or thickness. - Classic examples include **freckles, flat nevi, and café-au-lait spots**. - The image demonstrates the typical appearance with clear borders and no vertical component. *Papule* - A papule is an **elevated, solid lesion less than 1 cm** in diameter. - Unlike the lesion shown, papules have a **palpable raised component** above the skin surface. - Examples include acne, warts, and lichen planus. *Patch* - A patch is similar to a macule but is **larger than 1 cm in diameter**. - While also flat, the size criterion differentiates it from a macule. - Examples include vitiligo patches and large birthmarks. *Nodule* - A nodule is a **solid, elevated lesion greater than 1 cm** that extends into deeper skin layers. - It has both elevation and depth, unlike the flat lesion shown. - Examples include dermatofibromas, lipomas, and some cysts.
Question 4: A child presents with grouped vesicles on the lips. What is the bedside investigation that you would like to do?
- A. Wood's lamp
- B. Slit skin smear
- C. Tzanck smear (Correct Answer)
- D. KOH
Explanation: ***Tzanck smear*** - A **Tzanck smear** is a rapid bedside test that can identify **multinucleated giant cells**, which are seen in herpes simplex virus infections. - The presence of **grouped vesicles on the lips** is highly suggestive of **herpes labialis** (HSV-1), which is primarily a **clinical diagnosis**. - Among the options provided, Tzanck smear is the only relevant bedside investigation, though it has **limited sensitivity and specificity** and **cannot distinguish between HSV and VZV**. - In modern practice, **PCR or direct immunofluorescence** are preferred when laboratory confirmation is needed, but Tzanck smear remains a low-cost option in resource-limited settings. *Wood's lamp* - A Wood's lamp uses **ultraviolet light** to detect certain fungal or bacterial infections by revealing characteristic fluorescence. - It is useful for conditions like **tinea capitis** (green fluorescence) and **erythrasma** (coral-red fluorescence), but has no role in diagnosing viral vesicular lesions. *Slit skin smear* - A **slit skin smear** is used to detect **acid-fast bacilli** in the diagnosis of **leprosy**. - It is not indicated for vesicular lesions and is irrelevant to herpes simplex infection. *KOH* - A **KOH (potassium hydroxide) mount** is used to diagnose **fungal infections** by dissolving keratinocytes and revealing fungal hyphae or spores. - It has no utility in diagnosing viral infections such as herpes simplex.
Question 5: A 45-year-old Ulcerative colitis patient presents with multiple painful lesions on both legs. What is the diagnosis?
- A. Pyoderma gangrenosum (Correct Answer)
- B. Febrile neutropenic dermatosis
- C. Necrotizing fasciitis
- D. Granulomatosis with polyangiitis
Explanation: ***Pyoderma gangrenosum*** - This patient has **ulcerative colitis**, which is strongly associated with **pyoderma gangrenosum**, a neutrophilic dermatosis. - The image shows characteristic **painful, rapidly expanding ulcers** with violaceous, undermined borders, typical of pyoderma gangrenosum. *Febrile neutropenic dermatosis* - This condition (also known as **Sweet syndrome**) occurs in patients with **neutropenia** and **fever**, presenting with painful erythematous plaques or nodules. - While systemic illness like ulcerative colitis can predispose to skin conditions, the specific presentation and lack of mentioned neutropenia make this less likely. *Necrotizing fasciitis* - **Necrotizing fasciitis** is a rapidly progressive, life-threatening infection of the deep fascia and subcutaneous tissue, typically presenting with severe pain, erythema, swelling, and crepitus. - The lesions in the image appear to be chronic ulcers with specific borders rather than acute, rapidly spreading infection of necrotizing fasciitis. *Granulomatosis with polyangiitis* - Also known as **Granulomatosis with polyangiitis (GPA)**, formerly **Wegener's granulomatosis**, this is an autoimmune vasculitis primarily affecting the respiratory tract and kidneys, and can cause skin lesions such as palpable purpura, nodules, or ulcers. - While skin lesions can occur, the characteristic features of **pyoderma gangrenosum** and its strong association with inflammatory bowel disease make it a more probable diagnosis in this context.
Question 6: Comment on the image shown:
- A. Corn
- B. Callosity
- C. Warts
- D. Cutaneous horn
- E. Arsenical keratosis (Correct Answer)
Explanation: ***Arsenical keratosis*** - The image shows characteristic **raindrop pigmentation** (alternating hypo/hyperpigmented macules) and **palmar/plantar keratoses** pathognomonic of chronic **arsenic toxicity**. - Associated with **Blackfoot disease** (peripheral vascular disease) and increased risk of **skin malignancies**, distinguishing it from benign hyperkeratotic conditions. *Corn* - A corn presents as a **single, localized lesion** with a **painful central core**, unlike the multiple diffuse keratotic lesions with pigmentary changes seen here. - Corns are **friction-induced** and lack the characteristic **raindrop pigmentation** associated with arsenic exposure. *Callosity* - Callosity results from **repeated friction and pressure** causing broad, flat hyperkeratotic thickening without pigmentary changes. - It lacks the **alternating hypo/hyperpigmented macules** and **corn-like keratoses** characteristic of arsenical toxicity. *Warts* - **Viral warts** caused by **HPV** show **black puncta** (thrombosed capillaries) and **papillomatous surface** upon examination. - They present as **elevated, rough lesions** without the **raindrop pigmentation** and flat keratotic appearance of arsenical keratosis. *Cutaneous horn* - A **cutaneous horn** appears as a **solitary, conical projection** of keratin resembling an animal horn, typically on sun-exposed areas. - It presents as a **single horn-like protrusion** rather than the **multiple flat keratoses** with pigmentary changes shown in arsenical keratosis.
Question 7: A 24-year-old male presents with a lesion at the site shown in the image for 4 years. He says it has increased in thickness over the years. Diagnosis is:
- A. Spitz nevus
- B. Hyper-melanosis of Ito
- C. Becker's nevus (Correct Answer)
- D. Congenital melanocytic nevus
Explanation: ***Becker's nevus*** - This lesion typically presents as a **unilateral, hyperpigmented patch** that often appears during childhood or adolescence, increasing in size and thickness with associated **hypertrichosis** (increased hair growth). The image shows a large, irregularly shaped, hyperpigmented area on the torso of a young male, consistent with this description. - The history of increasing thickness over four years further supports **Becker's nevus**, as it is known to progress in thickness and texture, often becoming more indurated and sometimes verrucous. *Spitz nevus* - Spitz nevus is a benign melanocytic nevus typically presenting as a **pink or red, dome-shaped papule or nodule**, commonly on the face or limbs. - It rapidly grows but does not typically present as a large, hyperpigmented patch with associated hypertrichosis like the lesion shown. *Hyper-melanosis of Ito* - Hypermelanosis of Ito (also known as incontinentia pigmenti achromians) is characterized by **streaky or whorled hypopigmented (lighter) skin lesions**, often present at birth or in early infancy. - The image clearly shows a **hyperpigmented (darker) lesion**, which directly contradicts the characteristic hypopigmentation of hypermelanosis of Ito. *Congenital melanocytic nevus* - Congenital melanocytic nevi are typically present **at birth** or become apparent shortly thereafter. While they can be large and hyperpigmented, they usually do not have the prominent feature of increasing thickness and hypertrichosis developing many years later in adolescence or early adulthood in the same way as Becker's nevus. - The description of a lesion appearing during adolescence and increasing in thickness and hairiness for four years makes Becker's nevus a more specific diagnosis than a general congenital melanocytic nevus.
Question 8: Identify the skin condition depicted in the image.
- A. Ichthyosis (Correct Answer)
- B. Syndromic ichthyosis
- C. Cutaneous sarcoidosis
- D. Leprosy
Explanation: ***Ichthyosis*** - The image clearly displays widespread **dry, scaling, and thickened skin**, consistent with the characteristic presentation of ichthyosis. - This condition is characterized by a defect in **skin barrier function** leading to excessive dryness and accumulation of scales. *Syndromic ichthyosis* - While syndromic ichthyosis also involves skin scaling, it is associated with **additional systemic symptoms** or **organ involvement**, which cannot be determined from this image alone. - The term "ichthyosis" broadly covers this appearance, and without more clinical information, specifying it as syndromic is not the most direct identification. *Leprosy* - Leprosy typically presents with **hypopigmented, anesthetic skin patches** or **nodules**, which are not seen in the image. - The texture and color changes in the image are not characteristic of the primarily neurological and dermatological manifestations of leprosy. *Cutaneous sarcoidosis* - Cutaneous sarcoidosis manifests as **reddish-brown papules, plaques, or nodules**, often on the face, neck, or extremities. - The widespread, fine scaling and dryness seen in the image do not align with the typical granulomatous lesions of sarcoidosis.
Question 9: Dyskeratosis refers to which of the following?
- A. Abnormal, premature keratinization within cells below the stratum granulosum. (Correct Answer)
- B. Discontinuity of the skin showing incomplete loss of epidermis.
- C. Keratinization with retained nuclei in the stratum corneum.
- D. Thickening of stratum corneum, often associated with a qualitative abnormality of keratin.
Explanation: ***Abnormal, premature keratinization within cells below the stratum granulosum.*** - **Dyskeratosis** is a histological term for **premature keratinization** of individual keratinocytes. - This typically occurs in cells that are *below* the **stratum granulosum**, often in the stratum spinosum, indicating abnormal differentiation. *Discontinuity of the skin showing incomplete loss of epidermis.* - This description refers to an **erosion** or **ulceration**, depending on the depth of the epidermal loss. - It does not specifically describe abnormal cellular keratinization. *Keratinization with retained nuclei in the stratum corneum.* - This is the definition of **parakeratosis**, which is a normal finding in mucous membranes but an abnormal finding in skin, often associated with disorders like **psoriasis**. - It indicates incomplete maturation of keratinocytes as they reach the stratum corneum. *Thickening of stratum corneum, often associated with a qualitative abnormality of keratin.* - This describes **hyperkeratosis**, which is an increase in the thickness of the **stratum corneum**. - While it can involve abnormal keratin, it refers to increased thickness, not premature individual cell keratinization.
Question 10: A patient presents with orange-hued skin lesions and hyperkeratotic palms and soles. A biopsy shows alternating parakeratosis and orthokeratosis. What is the most likely diagnosis?
- A. Pityriasis rubra pilaris (Correct Answer)
- B. Follicular psoriasis
- C. Keratosis follicularis
- D. Ichthyosis vulgaris
Explanation: ***Pityriasis rubra pilaris*** - This condition classically presents with **salmon-colored to orange-hued plaques** and **hyperkeratotic palms and soles**. - Histologically, Pityriasis rubra pilaris is characterized by **alternating parakeratosis and orthokeratosis** in vertical and horizontal directions ("checkerboard" pattern). *Follicular psoriasis* - While psoriasis can present with hyperkeratosis and scales, **follicular psoriasis** specifically involves the hair follicles, seen as follicular papules and pustules. - The classic alternating parakeratosis and orthokeratosis is more indicative of PRP than of follicular psoriasis, which typically shows more uniform parakeratosis. *Keratosis follicularis* - Also known as Darier disease, this condition presents with **greasy, crusted, foul-smelling papules** on seborrheic areas. - Histopathology reveals characteristic **dyskeratosis** with acantholytic cells (corps ronds and grains), which is different from the described alternating parakeratosis and orthokeratosis. *Ichthyosis vulgaris* - This is a genetic disorder characterized by **dry, scaly skin** due to impaired epidermal barrier function, often worse in winter. - Histopathology typically shows a **diminished or absent granular layer** and compact orthokeratosis without parakeratosis, differing from the biopsy findings.
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