Skin Tumors Practice Questions

Q: Necrobiosis lipoidica is a clinical finding associated with which of the following conditions?

Diabetes mellitus. **Explanation:** **Necrobiosis Lipoidica (NL)** is a chronic granulomatous skin disorder characterized by the degeneration of dermal collagen (necrobiosis) combined with a granulomatous response, thickening of blood vessel walls, and fat deposition. 1. **Why Diabetes Mellitus is Correct:** NL is most classically associated with **Diabetes Mellitus (DM)**. While only about 0.3–1.2% of diabetic patients develop NL, approximately **60–75% of patients with NL have or will develop diabetes**. The pathogenesis is thought to involve microangiopathy. Clinically, it presents as well-demarcated, erythematous papules that evolve into large, yellow-brown, atrophic, telangiectatic plaques, typically on the **pretibial area (shins)**. 2. **Analysis of Incorrect Options:** * **A. Diabetes Insipidus:** This is a disorder of water metabolism (ADH deficiency or resistance) and has no known association with necrobiotic skin conditions. * **B. Lyme Disease:** Caused by *Borrelia burgdorferi*, it is associated with *Erythema Chronicum Migrans*, not NL. * **D. Symmonds Disease:** Also known as panhypopituitarism, it leads to systemic endocrine deficiencies but does not manifest with NL. **High-Yield Clinical Pearls for NEET-PG:** * **Koebner Phenomenon:** NL can exhibit the Koebner phenomenon (lesions appearing at sites of trauma). * **Ulceration:** About 35% of NL lesions undergo ulceration, often following minor trauma. * **Treatment:** First-line treatment includes high-potency topical or intralesional corticosteroids. * **Distinction:** Unlike other diabetic skin markers (like Acanthosis Nigricans), the severity of NL does **not** correlate with glycemic control.

Q: Which of the following conditions is depicted?

Plexiform neurofibroma. ***Plexiform neurofibroma*** - Characteristic **"bag of worms"** appearance with diffuse, infiltrating **soft tissue masses** along nerve distributions, pathognomonic for **NF1**. - Presents as **rope-like**, **tortuous subcutaneous masses** that feel like a collection of intertwined cords or worms under the skin. *Von Hippel Lindau syndrome* - Primarily characterized by **retinal hemangioblastomas** and **cerebellar hemangioblastomas**, not cutaneous neurofibromas. - Associated with **renal cell carcinomas** and **pheochromocytomas**, lacking the distinctive soft tissue masses seen in plexiform neurofibromas. *Marfan syndrome* - Features **arachnodactyly** (long, slender fingers), **lens dislocation**, and **aortic root dilatation**. - Does not present with **cutaneous masses** or the characteristic "bag of worms" appearance. *Tuberous sclerosis* - Characterized by **ash-leaf spots**, **shagreen patches**, and **facial angiofibromas** (adenoma sebaceum). - Lacks the **plexiform growth pattern** and infiltrating soft tissue masses typical of neurofibromas.

Q: What is the most common origin of melanoma?

Junctional melanocytes. **Explanation:** **1. Why Junctional Melanocytes is correct:** Melanoma is a malignant tumor arising from **melanocytes**, the pigment-producing cells derived from the neural crest. In the skin, these cells are primarily located at the **dermo-epidermal junction** (the interface between the epidermis and dermis). Most melanomas originate from these junctional melanocytes, either de novo (70%) or from a pre-existing junctional or compound nevus. The initial "radial growth phase" of most melanomas occurs within the epidermis and along this junctional zone before invading deeper into the dermis. **2. Why the other options are incorrect:** * **Epidermal cells:** This is a broad term. While melanocytes reside in the epidermis, the term "epidermal cells" usually refers to keratinocytes. Malignancies of keratinocytes result in Squamous Cell Carcinoma (SCC), not melanoma. * **Basal cells:** These are the innermost cells of the epidermis. Malignant transformation of these cells leads to **Basal Cell Carcinoma (BCC)**, which is the most common skin cancer overall but distinct from melanoma. * **Follicular cells:** These cells make up the hair follicle. While rare subtypes of melanoma can involve the follicular epithelium (like Lentigo Maligna), they are not the primary origin for the majority of melanomas. **3. NEET-PG High-Yield Pearls:** * **Most common site:** In males, it is the **back**; in females, it is the **lower legs**. * **Most common subtype:** **Superficial Spreading Melanoma** (associated with intermittent sun exposure). * **Prognostic Factor:** The most important prognostic indicator for stage I and II melanoma is the **Breslow Depth** (vertical thickness measured in mm). * **ABCDE Criteria:** Used for clinical screening—**A**symmetry, **B**order irregularity, **C**olor variation, **D**iameter >6mm, **E**volving/Elevation.

Q: Prognosis of malignant melanoma depends upon:

Invasion of nearby nodes. **Explanation:** The prognosis of malignant melanoma is primarily determined by the extent of disease spread and the depth of the primary lesion. **1. Why "Invasion of nearby nodes" is correct:** The most important prognostic factor for malignant melanoma is the **Stage of the disease** at the time of diagnosis. According to the AJCC (American Joint Committee on Cancer) staging, the presence of regional lymph node metastasis (Stage III) significantly decreases the 5-year survival rate compared to localized disease (Stage I or II). Once the tumor invades nearby nodes, it indicates a high potential for systemic dissemination, making it the strongest predictor of outcome among the given options. **2. Why other options are incorrect:** * **Grade of tumor:** Unlike many other cancers, "grading" (degree of differentiation) is not a standard prognostic tool for melanoma. Instead, **Breslow’s Thickness** (measured in mm) and **Clark’s Levels** (anatomical depth) are used. * **Age of the patient:** While older age can be associated with a poorer prognosis, it is a secondary factor and not as definitive as nodal status. * **Site of lesion:** While lesions on the trunk, head, or neck (BANS area: Back, Axilla, Neck, Scalp) generally have a worse prognosis than those on the extremities, the anatomical site is less critical than the stage and depth of the lesion. **High-Yield Clinical Pearls for NEET-PG:** * **Single most important prognostic factor overall:** Lymph node involvement (Stage). * **Most important prognostic factor for Stage I & II (Localized disease):** Breslow’s Thickness (Vertical depth). * **Breslow’s Thickness:** Measured from the granular layer of the epidermis to the deepest point of tumor invasion. * **ABCDE Criteria for diagnosis:** Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving. * **Commonest site in Indians:** Palm and Soles (Acral Lentiginous Melanoma).

Q: Plexiform neurofibromatosis commonly affects which of the following nerves?

Trigeminal nerve. **Explanation:** **Plexiform neurofibromas** are pathognomonic for **Neurofibromatosis Type 1 (NF1)**. Unlike localized neurofibromas, these are congenital, diffuse, and involve multiple fascicles of a nerve, often described as a "bag of worms" on palpation. **Why Trigeminal Nerve is Correct:** While plexiform neurofibromas can involve any nerve, they have a strong predilection for the **Trigeminal nerve (Cranial Nerve V)**, particularly the **ophthalmic division (V1)**. Involvement of the V1 branch often leads to the classic clinical presentation of **S-shaped ptosis** of the upper eyelid. This is a high-yield association frequently tested in postgraduate exams. **Analysis of Incorrect Options:** * **Facial Nerve (A):** While the facial nerve can be compressed by tumors in the parotid or cerebellopontine angle (like vestibular schwannomas in NF2), it is not the primary site for plexiform neurofibromas. * **Peripheral Nerve (C):** Although plexiform neurofibromas *are* tumors of the peripheral nerves, the question asks which specific nerve is "commonly affected." The Trigeminal nerve is the most characteristic cranial nerve involved. * **Glossopharyngeal Nerve (D):** This nerve is rarely involved in NF1. **Clinical Pearls for NEET-PG:** * **Pathognomonic Sign:** Plexiform neurofibroma is one of the cardinal diagnostic criteria for NF1. * **Bag of Worms:** The classic physical exam finding. * **Malignant Transformation:** Unlike cutaneous neurofibromas, plexiform neurofibromas carry a 5-10% lifetime risk of transforming into **Malignant Peripheral Nerve Sheath Tumors (MPNST)**. * **Imaging:** MRI is the gold standard to assess the extent of the lesion.

Q: Which of the following is a slow-growing skin tumor that rarely metastasizes to lymph nodes?

Basal cell carcinoma. **Explanation:** **Basal Cell Carcinoma (BCC)** is the most common skin cancer globally. It is characterized by its **slow growth** and **locally invasive** nature. The defining clinical feature of BCC is its extremely low potential for lymphatic or distant metastasis (less than 0.1%). It arises from the non-keratinizing cells of the basal layer of the epidermis and typically presents as a pearly papule with telangiectasia, often on sun-exposed areas like the face. **Why the other options are incorrect:** * **Melanoma:** This is the most aggressive form of skin cancer. It has a high propensity for early lymphatic and hematogenous spread, making it the leading cause of skin cancer deaths. * **Squamous Cell Carcinoma (SCC):** While also sun-related, SCC grows faster than BCC and has a significant risk of metastasis (roughly 2–5%), especially when occurring on the lips, ears, or in chronic scars (Marjolin’s ulcer). * **Angiosarcoma:** This is a highly malignant, rapidly progressing vascular tumor. It is notorious for early metastasis and a poor prognosis. **Clinical Pearls for NEET-PG:** * **"Rodent Ulcer":** A clinical variant of BCC that causes extensive local tissue destruction if left untreated. * **Risk Factor:** Chronic UV exposure is the primary cause; however, BCC is also associated with **Gorlin Syndrome** (Basal Cell Nevus Syndrome). * **Histology:** Look for **"Peripheral Palisading"** of nuclei and **retraction artifacts** (clefts) between the tumor nests and the stroma. * **Location:** Most common above the line joining the tragus of the ear to the angle of the mouth.

Question 1

Necrobiosis lipoidica is a clinical finding associated with which of the following conditions?

Accepted Answer

Diabetes mellitus

Answer

Diabetes insipidus

Answer

Lyme disease

Answer

Symmonds disease

Question 2

Which of the following conditions is depicted?

Accepted Answer

Plexiform neurofibroma

Answer

Von Hippel Lindau syndrome

Answer

Marfan syndrome

Answer

Tuberous sclerosis

Question 3

What is the most common origin of melanoma?

Accepted Answer

Junctional melanocytes

Answer

Epidermal cells

Answer

Basal cells

Answer

Follicular cells

Question 4

Prognosis of malignant melanoma depends upon:

Accepted Answer

Invasion of nearby nodes

Answer

Grade of tumour

Answer

Age of the patient

Answer

Site of lesion

Question 5

Plexiform neurofibromatosis commonly affects which of the following nerves?

Accepted Answer

Trigeminal nerve

Answer

Facial nerve

Answer

Peripheral nerve

Answer

Glossopharyngeal nerve

Question 6

Which of the following is a slow-growing skin tumor that rarely metastasizes to lymph nodes?

Accepted Answer

Basal cell carcinoma

Answer

Melanoma

Answer

Squamous cell carcinoma

Answer

Angiosarcoma

Question 7

Increased incidence of carcinoma is observed with which of the following conditions?

Accepted Answer

Verrucous leukoplakia

Answer

Homogenous Leukoplakia

Answer

Nodular leukoplakia

Answer

None of the above

Question 8

Regarding malignant melanoma, all the following are true EXCEPT?

Accepted Answer

May show spontaneous regression.

Answer

Vertical depth of invasion is a prognostic indicator.

Answer

Occurs in actinic damaged skin.

Answer

Lentigo maligna is a type of malignant melanoma.

Question 9

What is the treatment for Stage I mycosis fungoides?

Accepted Answer

Radiation

Answer

Topical corticosteroid

Answer

Skin electron beam therapy

Answer

UVB therapy

Question 10

A 50-year-old male presented with a characteristic lesion on the face for 5 years which is slowly increasing in size and bleeds whenever it is scratched. The patient has a history of chronic sun exposure, and there is no evidence of pain or itching over the lesion. Biopsy from the lesion is performed. Which of the following drugs are approved for the above condition?

Accepted Answer

5-FU, Imiquimod, and Vismodegib

Answer

5-FU, Itraconazole, and Vismodegib

Answer

Imiquimod, Itraconazole, and Azathioprine

Answer

5-FU, Imiquimod, Itraconazole, and Azathioprine

Skin Tumors — MCQs

Skin Tumors — MCQs

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