Dermatopathology Practice Questions

Q: A 55-year-old farmer presents with a 2-year history of a slowly growing nodule on his nose with rolled borders and central ulceration. Biopsy shows nests of basaloid cells with peripheral palisading extending from the epidermis into the dermis, surrounded by stromal retraction. Mitoses are present but not prominent. Apply this pathological finding to determine appropriate management.

Mohs micrographic surgery. ***Mohs micrographic surgery*** - This patient presents with **Basal Cell Carcinoma (BCC)**, confirmed by biopsy showing **basaloid cells** with **peripheral palisading** and **stromal retraction**. - **Mohs micrographic surgery** is the gold standard for BCC in **high-risk locations** like the nose to ensure maximum **tissue conservation** and the highest cure rate. *Wide local excision with 2 cm margins* - Standard surgical excision typically requires **4-5 mm margins** for low-risk BCC; a **2 cm margin** is excessive and would cause significant unnecessary deformity to the nose. - Unlike Mohs, standard excision does not provide **100% margin evaluation** in real-time, increasing the risk of recurrence in critical facial areas. *Topical imiquimod therapy* - **Imiquimod** is generally reserved for **superficial BCC** in low-risk areas or when surgery is contraindicated. - It is not appropriate for **nodular BCC** or lesions located in high-risk "H-zone" areas of the face like the nose. *Radiation therapy as first-line treatment* - **Radiation therapy** is usually reserved for patients who are not surgical candidates or as **adjuvant therapy** for aggressive tumors. - It has a lower long-term cure rate compared to surgery and can lead to poor **cosmetic outcomes** or secondary malignancies over time. *Observation with serial photography* - Chronic **Basal Cell Carcinoma** is locally invasive and will continue to cause **tissue destruction** (the "rodent ulcer") if left untreated. - **Observation** is inappropriate as BCC does not spontaneously regress and surgical intervention is required to prevent further disfigurement.

Q: A 45-year-old woman presents with a pruritic rash on her wrists and ankles. Physical examination reveals flat-topped, polygonal, violaceous papules with white striae on their surface. Skin biopsy shows a dense band-like lymphocytic infiltrate at the dermal-epidermal junction with apoptotic keratinocytes and sawtooth rete ridges. Apply your knowledge to determine the most likely diagnosis.

Lichen planus. ***Lichen planus*** - This condition classically presents with the **'six Ps'**: **purple**, **pruritic**, **polygonal**, **planar (flat-topped)**, **papules**, and **plaques**, often featuring **Wickham striae** (white lacy lines). - Key histopathologic findings include a **band-like lymphocytic infiltrate** at the dermo-epidermal junction, **sawtooth rete ridges**, and necrotic keratinocytes known as **Civatte bodies**. *Lichen simplex chronicus* - Characterized by **thickened skin (lichenification)** resulting from chronic rubbing or scratching, rather than an idiopathic inflammatory eruption. - Histology shows **hyperkeratosis**, **granulosis**, and **vertical streaking** of collagen in the papillary dermis, lacking the band-like interface dermatitis. *Pityriasis rosea* - Typically begins with a **'herald patch'** followed by a generalized eruption in a **'Christmas tree' pattern** on the trunk. - Histology is non-specific, often showing **focal parakeratosis** and a perivascular lymphocytic infiltrate rather than sawtooth rete ridges. *Psoriasis vulgaris* - Presents with well-demarcated **erythematous plaques** with **silvery-white scales**, commonly on the elbows and knees. - Histopathology features **regular acanthosis** (club-shaped rete ridges), **absent stratum granulosum**, and **Munro microabscesses**. *Lupus erythematosus* - Cutaneous involvement usually presents as a **malar rash** or discoid plaques with **photosensitivity**. - Histology reveals **vacuolar degeneration** of the basal layer and a **perivascular/periappendageal** lymphocytic infiltrate, but lacks the classic band-like infiltrate and sawtooth rete ridges seen here.

Q: The following skin biopsy from a patient of leprosy is diagnostic of:

Lepromatous leprosy. ***Lepromatous leprosy*** - Skin biopsies in **lepromatous leprosy** show abundant **acid-fast bacilli** (AFB) within macrophages, forming globi [1]. - There is a characteristic **clear subepidermal zone** (Grenz zone) due to the absence of inflammatory infiltrate directly beneath the epidermis. *Histoid leprosy* - This is a rare variant of lepromatous leprosy characterized by **spindle-shaped histiocytes** arranged in a storiform or whorled pattern. - While it also has numerous **AFB**, the distinct histiocytic morphology differentiates it from typical lepromatous leprosy. *Tuberculoid leprosy* - Biopsies from **tuberculoid leprosy** show well-formed **granulomas** composed of epithelioid cells, Langerhans giant cells, and lymphocytes. - **AFB are very scanty or absent** in tuberculoid leprosy [1,2], making it difficult to find them on routine staining. *Borderline leprosy* - **Borderline leprosy** encompasses a spectrum, with features intermediate between tuberculoid and lepromatous forms. - The biopsy findings vary depending on the sub-type (e.g., borderline tuberculoid, borderline lepromatous), but generally show **less organized granulomas** and a **moderate number of AFB** compared to lepromatous leprosy. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 385-386. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 638-639.

Q: The following skin biopsy from a patient of leprosy is diagnostic of: (Recent NEET Pattern 2016-17)

Tuberculoid leprosy. ***Tuberculoid leprosy*** - The image shows well-formed **granulomas** with **epithelioid cells**, **Langhans giant cells**, and a surrounding lymphocytic infiltrate [2], which are characteristic of a strong cell-mediated immune response against *Mycobacterium leprae* [1]. - **Acid-fast bacilli (AFB)** are typically **sparse or absent** in tuberculoid leprosy due to effective immune containment [1][3]. *Histoid leprosy* - Characterized by the presence of **spindle-shaped histiocytes** arranged in a storiform or whorled pattern. - Contains a **large number of AFB**, often arranged in globi, which is not consistent with the described image. *Lepromatous leprosy* - Shows a diffuse infiltrate of **foamy macrophages** (Virchow cells) filled with numerous **AFB** (globi) [1]. - **Granulomas are poorly formed or absent** due to a deficient cell-mediated immune response [3]. *Borderline leprosy* - Represents a spectrum between tuberculoid and lepromatous forms, with features of both. - Histologically, it shows **granulomas that are less well-defined** than tuberculoid leprosy and contain a variable number of AFB, more than tuberculoid but less than lepromatous. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 385-386. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 109. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 638-639.

Q: The following is a picture from scrapping of genital ulcer. Comment on the diagnosis. (AIIMS May 2017)

Haemophilus ducreyi. ***Hemophilus ducreyi*** - *Hemophilus ducreyi* causes **chancroid**, characterized by painful genital ulcers with ragged, undermined borders and often associated with painful inguinal lymphadenopathy. - Microscopic examination of a smear from the ulcer typically shows **Gram-negative coccobacillary rods** arranged in "school of fish" or "railroad track" patterns. *Klebsiella granulomatosis* - *Klebsiella granulomatosis* (formerly *Calymmatobacterium granulomatis*) causes **donovanosis** (granuloma inguinale), which presents as painless, beefy red, friable ulcers [1]. - Diagnosis is made by identifying **Donovan bodies** (intracellular bipolar-staining rods) in tissue smears or biopsies [1]. *Neisseria gonorrhoea* - *Neisseria gonorrhoea* primarily causes **urethritis** in men and **cervicitis** in women, with purulent discharge. - While it can cause disseminated infection, it typically does not present as a primary genital ulcer. *Chlamydia trachomatis* - *Chlamydia trachomatis* causes **lymphogranuloma venereum (LGV)**, which initially presents as a transient, painless papule or ulcer, often unnoticed. - The characteristic feature of LGV is the subsequent development of **painful inguinal lymphadenopathy** (buboes) and proctitis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 378-379.

Q: A 12-year-old boy develops multiple lumps in the skin. Biopsy of the lumps is shown below. What is the probable causative agent? (NEET Pattern 2019)

Cysticercus cellulosae. ***Cysticercus cellulosae*** - The presence of multiple lumps in the skin, particularly in a child, is highly suggestive of **subcutaneous cysticercosis** [1]. - **_Cysticercus cellulosae_** is the larval stage of **_Taenia solium_** (pork tapeworm), which commonly encysts in subcutaneous tissues, muscles, and the brain in humans [1]. *Cysticercus bovis* - **_Cysticercus bovis_** is the larval stage of **_Taenia saginata_** (beef tapeworm). - It primarily infects cattle and is not a common cause of subcutaneous lumps in humans. *Echinococcus granulosus* - **_Echinococcus granulosus_** causes **hydatid disease**, forming large cysts primarily in the liver and lungs [1]. - While it can form cysts in other organs, it typically presents as large, solitary cysts rather than multiple small subcutaneous lumps. *Hymenolepis Nana* - **_Hymenolepis nana_** is the **dwarf tapeworm** and is the most common cestode infection in humans. - It is an intestinal parasite and does not form cysts or lumps in the skin. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 403-405.

Q: Identify the histopathological slide shown below:

Toxic epidermal necrolysis. ***Toxic epidermal necrolysis*** - Histopathology of **Toxic Epidermal Necrolysis (TEN)** characteristically shows **full-thickness epidermal necrosis** with minimal or no dermal inflammation [1]. - This extensive epidermal death leads to the characteristic **Nikolsky's sign** and widespread skin detachment. *Lepromatous leprosy* - Histology of **lepromatous leprosy** typically reveals a large number of **acid-fast bacilli** within macrophages, forming foamy cells. - There is often a **grenz zone** (a clear zone) separating the inflammatory infiltrate from the overlying epidermis. *Pemphigus vulgaris* - **Pemphigus vulgaris** is characterized by **suprabasal acantholysis**, leading to the formation of intraepidermal blisters. - Immunofluorescence studies show a characteristic **"chicken wire" pattern** of IgG and C3 deposition on the cell surface of keratinocytes. *Mycosis fungoides* - **Mycosis fungoides** is a cutaneous T-cell lymphoma, and its histology shows an epidermotropic infiltrate of atypical lymphocytes [2]. - Characteristic findings include **Pautrier microabscesses** (collections of atypical lymphocytes in the epidermis) and cerebriform nuclei of the lymphocytes [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1166-1168. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 564-565.

Question 1

A 55-year-old farmer presents with a 2-year history of a slowly growing nodule on his nose with rolled borders and central ulceration. Biopsy shows nests of basaloid cells with peripheral palisading extending from the epidermis into the dermis, surrounded by stromal retraction. Mitoses are present but not prominent. Apply this pathological finding to determine appropriate management.

Accepted Answer

Mohs micrographic surgery

Answer

Wide local excision with 2 cm margins

Answer

Topical imiquimod therapy

Answer

Radiation therapy as first-line treatment

Answer

Observation with serial photography

Question 2

A 28-year-old man with a history of recurrent staphylococcal abscesses presents with multiple painful nodules in the axillae and groin that drain purulent material. Biopsy shows dilated follicles with keratinous plugging, mixed inflammatory infiltrate with neutrophils, and sinus tract formation extending into the subcutaneous tissue. Apply this information to guide management.

Accepted Answer

Long-term antibiotics with TNF-alpha inhibitors for severe disease

Answer

Antifungal therapy

Answer

Topical antibiotics only

Answer

Systemic antibiotics with incision and drainage

Answer

Topical corticosteroids

Question 3

A 45-year-old woman presents with a pruritic rash on her wrists and ankles. Physical examination reveals flat-topped, polygonal, violaceous papules with white striae on their surface. Skin biopsy shows a dense band-like lymphocytic infiltrate at the dermal-epidermal junction with apoptotic keratinocytes and sawtooth rete ridges. Apply your knowledge to determine the most likely diagnosis.

Accepted Answer

Lichen planus

Answer

Lichen simplex chronicus

Answer

Pityriasis rosea

Answer

Psoriasis vulgaris

Answer

Lupus erythematosus

Question 4

The following skin biopsy from a patient of leprosy is diagnostic of:

Accepted Answer

Lepromatous leprosy

Answer

Histoid leprosy

Answer

Tuberculoid leprosy

Answer

Borderline leprosy

Answer

Indeterminate leprosy

Question 5

The following skin biopsy from a patient of leprosy is diagnostic of: (Recent NEET Pattern 2016-17)

Accepted Answer

Tuberculoid leprosy

Answer

Histoid leprosy

Answer

Lepromatous leprosy

Answer

Borderline leprosy

Answer

Indeterminate leprosy

Question 6

The following is a picture from scrapping of genital ulcer. Comment on the diagnosis. (AIIMS May 2017)

Accepted Answer

Haemophilus ducreyi

Answer

Klebsiella granulomatosis

Answer

Neisseria gonorrhoea

Answer

Chlamydia trachomatis

Answer

Treponema pallidum

Question 7

A 12-year-old boy develops multiple lumps in the skin. Biopsy of the lumps is shown below. What is the probable causative agent? (NEET Pattern 2019)

Accepted Answer

Cysticercus cellulosae

Answer

Cysticercus bovis

Answer

Echinococcus granulosus

Answer

Hymenolepis Nana

Answer

Echinococcus multilocularis

Question 8

Identify the histopathological slide shown below:

Accepted Answer

Toxic epidermal necrolysis

Answer

Lepromatous leprosy

Answer

Pemphigus vulgaris

Answer

Mycosis fungoides

Answer

Bullous pemphigoid

Dermatopathology — MCQs

Dermatopathology — MCQs

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