INI-CET 2017 - Dermatology Practice Questions

Q: The image given below shows:

Cutaneous horn. ***Cutaneous horn (Cornu cutaneum)*** - The image distinctly shows an **exophytic, conical, or cylindrical lesion** composed of compact keratin, resembling an animal's horn, which is characteristic of a cutaneous horn. - A cutaneous horn is a **clinical descriptive term** for a keratinous projection and is NOT of sebaceous origin; it can arise from various underlying conditions including **seborrheic keratosis, viral warts, actinic keratosis**, or benign lesions. - Importantly, cutaneous horns can rarely **harbor squamous cell carcinoma** or other underlying skin cancers at their base (up to 20% have underlying malignancy), necessitating biopsy and histopathological examination. *Papilloma* - A papilloma is a general term for a **benign epithelial tumor** growing exophytically in a frond-like or papillary pattern, often softer and not typically forming such a dense, hardened projection. - While some papillomas can be keratotic, they usually lack the extreme **horn-like appearance** made of densely packed keratin seen in the image. *Cock's peculiar tumor* - Cock's peculiar tumor, also known as a **calcifying epithelioma of Malherbe** or **pilomatricoma**, is typically a firm, deep-seated nodule arising from hair matrix cells, often with a bluish or reddish hue. - It does not present as a **hard, projecting, horn-like accumulation of keratin** on the skin surface. *Glomus tumor* - A glomus tumor is a rare, **benign neurovascular tumor** typically found in the digits (especially subungual), characterized by exquisite pain, cold sensitivity, and often present as a small, reddish-blue nodule. - Its presentation is distinctly different from the **hyperkeratotic cutaneous projection** shown and does not form a horn-like structure.

Q: A patient presents with ulcer on the side of the nose, as shown, which bleeds on itching. What is the diagnosis? (AIIMS Nov 2017)

Basal cell carcinoma. ***Basal cell carcinoma*** - The image shows a **pearly appearance** with a **central ulceration** and **rolled borders**, which are classic clinical features of **nodular basal cell carcinoma**. - **Bleeding upon minor trauma or itching** (friability) is also a common characteristic of basal cell carcinoma, especially the ulcerated form. *Squamous cell carcinoma* - Squamous cell carcinoma typically presents as a **crusted, firm, red nodule** or a **patch with scales and ulceration**, often in sun-exposed areas. - While it can ulcerate and bleed, it usually lacks the distinct **pearly appearance and rolled borders** seen in basal cell carcinoma. *Marjolin ulcer* - A Marjolin ulcer is a **malignant degeneration of a chronic ulcer**, burn scar, or chronic inflammatory lesion, most commonly an aggressive squamous cell carcinoma. - It would present in the context of a **pre-existing long-standing lesion** or scar, which is not indicated here, and generally has a more irregular, indurated appearance. *Nevus* - A nevus (mole) is a benign growth of pigment-producing cells which typically presents as a **well-demarcated pigmented lesion**. - While some nevi can be raised or irregular, they generally do **not ulcerate spontaneously or bleed easily** on scratching unless traumatized, nor do they typically have the pearly, rolled borders of a basal cell carcinoma.

Q: A female had a thorn prick 5 years ago. She presents with development of slowly growing $2 \times 2 \mathrm{~cm}$ verrucous lesion which on KOH mount shows the following image. Diagnosis is: (AIIMS Nov 2017)

Chromoblastomycosis. ***Chromoblastomycosis*** - The image shows **sclerotic bodies** (also known as **Medlar bodies**, muriform cells, or fumagoid cells) which are characteristic of *Chromoblastomycosis*. These are thick-walled, septate, dematiaceous (darkly pigmented) fungal cells that reproduce by septation in multiple planes. - The history of a **thorn prick** (trauma allowing inoculation of fungal spores from soil/vegetation), the **slowly growing verrucous lesion**, and the presence of sclerotic bodies on KOH mount are all highly specific for chromoblastomycosis. *Sporotrichosis* - **Sporotrichosis** typically presents with subcutaneous nodules that ulcerate, often forming a **lymphocutaneous spread** along lymphatic vessels. - On microscopy (KOH mount or biopsy), *Sporothrix schenckii* appears as **cigar-shaped budding yeasts** in tissue, which are not seen in the provided image. *Blastomycosis* - **Blastomycosis** is caused by *Blastomyces dermatitidis* and can cause pulmonary, cutaneous, and disseminated infections. Cutaneous lesions can be verrucous but are typically granulomatous with microabscesses. - Microscopic examination (KOH mount) reveals **large, broad-based budding yeast cells**, which are distinct from the sclerotic bodies shown. *Phaeohyphomycosis* - **Phaeohyphomycosis** encompasses a diverse group of infections caused by dematiaceous (pigmented) fungi that, in tissue, grow as **septate hyphae**, yeast-like cells, or a combination of both, but **do not form sclerotic bodies**. - While it can manifest as subcutaneous nodules or cysts, the diagnostic feature in tissue is the presence of pigmented hyphal forms, unlike the characteristic sclerotic bodies in the image.

Q: The following presentation is called:

Mycetoma. ***Mycetoma*** - The image displays a foot with **swelling, nodule formation, and draining sinuses** with visible grains, which is characteristic of mycetoma. - Mycetoma is a **chronic, progressive granulomatous disease** of the skin, subcutaneous tissue, fascia, and bone, often affecting the foot. *Black foot disease* - This is a form of **peripheral vascular disease** caused by **chronic arsenic poisoning**, typically leading to **gangrene** and eventually amputation. - The image does not show the typical features of **ischemia or gangrene** associated with Black foot disease. *Myrmecia* - This is a type of **wart or verruca** that is specifically characterized by a **plantar wart with a central core of black dots** (thrombosed capillaries). - The image shows a more widespread inflammatory process with nodules and sinuses, not a localized wart. *Tinea pedis* - Also known as **athlete's foot**, this is a **superficial fungal infection** of the skin of the foot, typically presenting with **scaling, itching, redness, and sometimes blisters**. - The clinical presentation in the image, with deep-seated nodules and draining sinuses, is not consistent with a superficial fungal infection.

Question 1

The image given below shows:

Accepted Answer

Cutaneous horn

Answer

Papilloma

Answer

Cock's peculiar tumor

Answer

Glomus tumor

Question 2

A patient presents with ulcer on the side of the nose, as shown, which bleeds on itching. What is the diagnosis? (AIIMS Nov 2017)

Accepted Answer

Basal cell carcinoma

Answer

Squamous cell carcinoma

Answer

Marjolin ulcer

Answer

Nevus

Question 3

A female had a thorn prick 5 years ago. She presents with development of slowly growing $2 	imes 2 \mathrm{~cm}$ verrucous lesion which on KOH mount shows the following image. Diagnosis is: (AIIMS Nov 2017)

Accepted Answer

Chromoblastomycosis

Answer

Sporotrichosis

Answer

Blastomycosis

Answer

Phaeohyphomycosis

Question 4

The following presentation is called:

Accepted Answer

Mycetoma

Answer

Black foot disease

Answer

Myrmecia

Answer

Tinea pedis

INI-CET 2017 — Dermatology