Dermatopathology Practice Questions

Q: Acanthosis involves -

Str spinosum. **Str spinosum** - **Acanthosis** refers to the **thickening of the stratum spinosum** due to an increase in the number of keratinocytes. - This cellular proliferation leads to clinical thickening of the epidermis, often seen in conditions like psoriasis. *Str Basale* - The **stratum basale** is the deepest layer of the epidermis, responsible for **cell division and regeneration**. - While essential for epidermal turnover, its primary thickening is not what defines acanthosis. *Str corneum* - The **stratum corneum** is the outermost layer, composed of dead, keratinized cells, primarily associated with **hyperkeratosis** (thickening of this layer). - Acanthosis specifically refers to the proliferation within the living layers of the epidermis below the granular layer. *Str granulosum* - The **stratum granulosum** lies between the stratum spinosum and stratum corneum and is involved in **keratinization**. - Thickening of this layer is typically termed **hypergranulosis** and is distinct from acanthosis.

Q: Psoriasis has the following features except

Prominent granular cell layer. ***Prominent granular cell layer*** - Psoriatic skin lesions are characterized by a **thinned or absent granular cell layer (stratum granulosum)**, not a prominent one. - This observation is often used histopathologically to differentiate psoriasis from other skin conditions. *Granular cell layer is thinned or almost absent* - This statement accurately describes a key histological feature of psoriasis, where the **stratum granulosum** is significantly reduced or missing. - The absence of this layer is linked to the rapid epidermal turnover seen in psoriatic plaques. *Munro abscesses in the parakeratotic layer* - **Munro microabscesses** are collections of neutrophils found within the **parakeratotic stratum corneum** in psoriatic lesions [1]. - These microabscesses are a characteristic histopathological finding that helps in the diagnosis of psoriasis. *Suprapapillary thinning of epidermis* - There is a characteristic **thinning of the suprapapillary epidermis** (the epidermis directly above the dermal papillae) [1]. - This thinning, combined with dilated capillaries in the dermal papillae, contributes to the **Auspitz sign**, where pinpoint bleeding occurs after scratching the surface of a psoriatic plaque [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 636-641.

Q: In Still's disease the transient cutaneous rash coincides with the fever spike. The rash is due to:

Neutrophil infiltration in the dermis. ***Neutrophil infiltration in the dermis*** - The characteristic rash of Still's disease (juvenile idiopathic arthritis systemic onset or adult-onset Still's disease) is a **transient, salmon-pink, macular or maculopapular eruption** that typically appears during **febrile spikes**. - Histologically, this rash is characterized by a **superficial perivascular infiltrate of neutrophils** and sometimes lymphocytes, without significant epidermal changes. *Lymphocyte infiltration in the dermis* - While lymphocytes can be present, the predominant inflammatory cell type associated with the classic rash of Still's disease during fever spikes is the **neutrophil**. - Conditions like chronic dermatitis or viral exanthems are more commonly associated with prominent lymphocytic infiltrates. *Eosinophil infiltration in the dermis* - Eosinophils are typically associated with **allergic reactions**, parasitic infections, or certain drug eruptions. - Their presence is not a primary feature of the rash seen in Still's disease. *None of the options* - This option is incorrect because **neutrophil infiltration** is the recognized histological feature of the rash in Still's disease.

Q: Acanthosis involves:-

Stratum malphigii. ***Stratum malphigii*** - **Acanthosis** refers to an increase in the thickness of the **stratum spinosum** (also known as the stratum malpighii) of the epidermis [1]. - This thickening is due to an increase in the number of **keratinocytes** in this layer and is a common histological feature in various skin conditions, such as psoriasis [1]. *Stratum lucidum* - The **stratum lucidum** is a thin, clear layer of the epidermis found only in thick skin (palms and soles). - It consists of flat, densely packed keratinocytes and is not typically involved in acanthosis. *Stratum corneum* - The **stratum corneum** is the outermost layer of the epidermis, composed of dead, flattened keratinocytes. - An increase in its thickness is called **hyperkeratosis**, not acanthosis. *Stratum granulosum* - The **stratum granulosum** is characterized by cells containing keratohyalin granules. - Changes in this layer are usually described as **hypergranulosis** (increased thickness) or hypogranulosis (decreased thickness), which are distinct from acanthosis. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 640-641.

Q: Skin biopsy shows psoriasiform hyperplasia with neutrophilic microabscesses in stratum corneum. Most likely diagnosis?

Psoriasis. ***Psoriasis*** - **Psoriasiform hyperplasia**, characterized by regular epidermal acanthosis and elongated rete ridges, is a classic histological feature of psoriasis. - The presence of **neutrophilic microabscesses (Munro microabscesses)** in the stratum corneum is a pathognomonic finding for psoriasis. *Seborrheic dermatitis* - Histologically, seborrheic dermatitis typically shows **irregular acanthosis** with parakeratosis and a **perivascular lymphocytic infiltrate**, but not regular psoriasiform hyperplasia or Munro microabscesses. - There may be *spongiosis* and neutrophils in the stratum corneum, but not the distinct microabscesses seen in psoriasis. *Pityriasis rosea* - Pityriasis rosea histology often reveals **focal parakeratosis**, **spongiosis**, and a **perivascular lymphocytic infiltrate** with extravasated red blood cells. - It does not demonstrate the characteristic regular psoriasiform hyperplasia or neutrophilic microabscesses of psoriasis. *Lichen planus* - Lichen planus is characterized by a **"sawtooth" rete ridge pattern**, a **band-like lymphocytic infiltrate** at the dermo-epidermal junction, and **colloid bodies (Civatte bodies)**. - It does not exhibit psoriasiform hyperplasia or neutrophilic microabscesses in the stratum corneum.

Q: Patient with pigmented skin lesion shows pagetoid spread of atypical melanocytes. Diagnosis?

Superficial spreading melanoma. ### Superficial spreading melanoma - This is the most common type of melanoma and is characterized by a **radial growth phase** where atypical melanocytes spread along the **dermo-epidermal junction** and into the epidermis (pagetoid spread) [1]. - **Pagetoid spread**, referring to the upward migration of atypical melanocytes into the spinous and granular layers of the epidermis, is a hallmark histological feature. *Lentigo maligna* - This is a melanoma subtype primarily affecting **chronically sun-damaged skin** in older individuals, typically on the face. - While it has a prolonged **radial growth phase**, the atypical melanocytes tend to be confined to the **basal layer** and do not typically exhibit prominent pagetoid spread like superficial spreading melanoma. *Blue nevus* - A blue nevus is a **benign melanocytic lesion** characterized by the presence of dermal melanocytes that produce melanin deep within the dermis, giving it a characteristic blue or blue-gray color [2]. - It does not involve **atypical melanocytes** or **pagetoid spread** (upward migration of cells into the epidermis). *Nodular melanoma* - This is an aggressive subtype of melanoma characterized by a rapid **vertical growth phase** and minimal or absent radial growth phase [1]. - It presents as a **dark, raised nodule** and typically lacks the prominent pagetoid spread seen in the superficial spreading type, as its growth is primarily downward into the dermis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1151-1152. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, p. 1146.

Q: In which skin disorder is the appearance of basal cells resembling a row of tombstones observed?

Pemphigus vulgaris. ***Pemphigus vulgaris*** - This autoimmune blistering disease is characterized by **acantholysis** (loss of cell-to-cell adhesion) in the **suprabasal layer** of the epidermis [2]. - The intact basal keratinocytes remain attached to the basement membrane, forming a characteristic "row of **tombstones**" appearance on histology [1]. *Pemphigus foliaceus* - This condition involves acantholysis in the more **superficial granular layer** of the epidermis, above the basal layer [2]. - This leads to subcorneal blistering and **crusted lesions**, but not the tombstone appearance [2]. *Erythema multiforme* - This is a **(type IV hypersensitivity reaction)** characterized by **target lesions** and **vacuolar degeneration** of the basal cell layer. - While it affects the basal layer, it does not involve acantholysis or the "tombstone" pattern. *Bullous pemphigoid* - This is a **subepidermal blistering disease** where autoantibodies target components of the **hemidesmosomes** at the dermoepidermal junction [2]. - The entire epidermis separates from the dermis, resulting in a **tense blister** and no acantholysis or tombstone appearance [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 645-646. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1170-1172.

Q: A 60-year-old male presents with an indurated ulcer on the lower lip and has a history of sun exposure. A biopsy reveals atypical squamous cells invading the dermis. What is the diagnosis?

Squamous cell carcinoma (SCC). ***Squamous cell carcinoma (SCC)*** - An **indurated ulcer** on the lower lip in a patient with a history of **sun exposure** is highly suggestive of SCC, as UV radiation is a primary risk factor [1]. - The biopsy showing **atypical squamous cells invading the dermis** confirms the diagnosis of invasive squamous cell carcinoma [2]. *Actinic keratosis* - This is a **precancerous lesion** caused by chronic sun exposure, often presenting as rough, scaly patches [3]. - While it can progress to SCC, it is not an invasive carcinoma, and the biopsy here describes dermal invasion. *Melanoma* - While also associated with sun exposure, melanoma typically originates from **melanocytes** and presents as an asymmetrical, irregular-bordered, multi-colored lesion with a changing diameter. - The biopsy demonstrating **atypical squamous cells**, not melanocytes, rules out melanoma. *Basal cell carcinoma* - This is the **most common form of skin cancer**, often presenting as a pearly nodule with rolled borders and telangiectasias, or a non-healing ulcer [2]. - While it can occur on sun-exposed areas, the biopsy finding of **atypical squamous cells** distinguishes it from basal cell carcinoma, which arises from basal cells. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 643-644. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, p. 1158. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, p. 1156.

Q: A 70-year-old man presents with an enlarging mass in the neck. A biopsy reveals spindle cells that are positive for S100 and HMB-45. Which malignancy is most consistent with these findings?

Melanoma. ***Melanoma*** - The presence of **spindle cells** combined with positive staining for **S100** and **HMB-45** is highly characteristic of melanoma, which can present as a metastatic neck mass [1]. - **S100 protein** is a marker for neural crest-derived cells, and **HMB-45** is specific for melanosomes, both indicating melanocytic differentiation [1]. *Non-Hodgkin Lymphoma* - Lymphomas typically stain positive for **leukocyte common antigen (CD45)** and various B-cell or T-cell markers, not S100 or HMB-45. - The morphology is usually that of lymphoid cells, not spindle cells. *Soft Tissue Sarcoma* - While sarcomas can be composed of spindle cells, their immunohistochemical profile varies widely depending on the specific type (e.g., vimentin, desmin, actin) and would not typically include strong positivity for S100 and HMB-45. - These markers are not characteristic of the vast majority of soft tissue sarcomas. *Epithelial Carcinoma* - Carcinomas are typically composed of epithelial cells and express **cytokeratins**, not S100 or HMB-45. - Although some carcinomas can show spindle cell morphology, the specific immunophenotype rules out this diagnosis. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1151-1152.

Question 1

Acanthosis involves -

Accepted Answer

Str spinosum

Answer

Str basale

Answer

Str corneum

Answer

Str granulosum

Question 2

Psoriasis has the following features except

Accepted Answer

Prominent granular cell layer

Answer

Granular cell layer is thinned or almost absent.

Answer

Munro abscesses in the parakeratotic layer

Answer

Acanthosis with thickened lower portion

Answer

Suprapapillary thinning of  epidermis

Question 3

In Still's disease the transient cutaneous rash coincides with the fever spike. The rash is due to:

Accepted Answer

Neutrophil infiltration in the dermis

Answer

Lymphocyte infiltration in the dermis

Answer

Eosinophil infiltration in the dermis

Answer

None of the options

Question 4

Acanthosis involves:-

Accepted Answer

Stratum malphigii

Answer

Stratum lucidum

Answer

Stratum corneum

Answer

Stratum granulosum

Question 5

Skin biopsy shows psoriasiform hyperplasia with neutrophilic microabscesses in stratum corneum. Most likely diagnosis?

Accepted Answer

Psoriasis

Answer

Seborrheic dermatitis

Answer

Pityriasis rosea

Answer

Lichen planus

Question 6

Patient with pigmented skin lesion shows pagetoid spread of atypical melanocytes. Diagnosis?

Accepted Answer

Superficial spreading melanoma

Answer

Lentigo maligna

Answer

Blue nevus

Answer

Nodular melanoma

Question 7

In which skin disorder is the appearance of basal cells resembling a row of tombstones observed?

Accepted Answer

Pemphigus vulgaris

Answer

Pemphigus foliaceus

Answer

Erythema multiforme

Answer

Bullous pemphigoid

Question 8

Which histological finding is most characteristic of psoriasis?

Accepted Answer

Munro microabscesses

Answer

Acantholysis

Answer

Granular IgG deposits

Answer

Row of tombstones

Question 9

A 60-year-old male presents with an indurated ulcer on the lower lip and has a history of sun exposure. A biopsy reveals atypical squamous cells invading the dermis. What is the diagnosis?

Accepted Answer

Squamous cell carcinoma (SCC)

Answer

Melanoma

Answer

Actinic keratosis

Answer

Basal cell carcinoma

Question 10

A 70-year-old man presents with an enlarging mass in the neck. A biopsy reveals spindle cells that are positive for S100 and HMB-45. Which malignancy is most consistent with these findings?

Accepted Answer

Melanoma

Answer

Non-Hodgkin Lymphoma

Answer

Soft Tissue Sarcoma

Answer

Epithelial Carcinoma

Dermatopathology — MCQs

Dermatopathology — MCQs

On this page

Practice by Chapter

Want unlimited practice?