Exclusive Cutaneous and Subcutaneous Sarcoidal Granulomatous Inflammation due to Immune Checkpoint Inhibitors: Report of Two Cases with Unusual Manifestations and Review of the Literature.

Recent emergence of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of cancers and produced prolonged response by boosting the immune system against tumor cells. The primary target antigens are cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), a downregulator of T-cell activation, and programmed cell death-1 receptor (PD-1), a regulator of T-cell proliferation. This enhanced immune response can induce autoimmune adverse effects in many organs.

Neutrophilic Dermatosis of the Dorsal Hands: Report of a Case and Review of the Literature.

Neutrophilic dermatosis of the dorsal hands is an underrecognized entity, which is a distributional variant of Sweet's syndrome. It is often clinically misdiagnosed as an infectious process in overwhelming majority of the cases and the treatment is therefore delayed. Also, its association with underlying systemic and neoplastic disorders makes the need for an accurate diagnosis more crucial.

Linear IgA Bullous Dermatosis: A Rare Clinicopathologic Entity with an Unusual Presentation.

Linear immunoglobulin A bullous dermatosis is a rare autoimmune mucocutaneous disorder caused by immunoglobulin A autoantibodies produced against several different antigens in the basement membrane zone. Clinically, it is characterized by tense vesicles or bullae, which on histopathological exam demonstrate subepidermal blister with a predominantly neutrophilic infiltrate. A smooth, linear pattern of immunoglobulin A deposition in the basement membrane zone on direct immunofluorescence is considered the gold standard for establishing a diagnosis.

Primary carcinosarcoma of the ear: case report and review of the literature.

Primary carcinosarcoma is a very rare neoplasm comprising two intermingling malignant components-epithelial and mesenchymal. The authors report a new case of primary cutaneous carcinosarcoma involving the helix of the ear. Immunohistochemical analysis revealed epithelial components of both basal cell and squamous cell carcinomas with a partially ossified sarcomatous-like component.

Erythropoietic protoporphyria: a case report and literature review.

Erythropoietic protoporphyria is considered a rare disease overall, but in children is the most common form of porphyria, and certainly the most common type of erythropoietic porphyria. Despite this fact, erythropoietic protoporphyria is a disease that has been known to evade or at least delay diagnosis, leading to unnecessary suffering by the patient. Given the distress it may cause a patient and his or her family as well as the potential complications of this disease, the importance of maintaining a heightened awareness when presented with a child complaining of photosensitivity cannot be overstated.

Acute generalized exanthematous pustulosis: an enigmatic drug-induced reaction.

Acute generalized exanthematous pustulosis (AGEP) is a diffuse pustular disorder that is primarily drug induced and characterized by acute, extensive, small, nonfollicular, sterile pustules that usually begin in intertriginous folds with widespread edema and erythema. This article reports a case in which thalidomide, dexamethasone, or meloxicam may have been the etiologic agent to induce AGEP and the skin condition may have worsened with administration of additional medications during hospital admission. A good thorough medical history, including a drug history, along with clinicopathologic correlation is extremely important in a patient presenting with acute diffuse pustular lesions.

Acantholytic anaplastic Paget's disease.

Classic Paget's disease (PD) can be diagnosed relatively easily by histopathologic examination. 'Anaplastic' variant of this disease is a less-recognized subset that may pose as a diagnostic challenge and pitfall. We describe two cases who presented with scaly erythematous plaques on their nipple/areola.

Cutaneous epithelioid angiosarcoma: a neoplasm with potential pitfalls in diagnosis.

Angiosarcoma (AS) is a rare neoplasm. Cutaneous AS is the most common form of AS. The epithelioid variant of the disease, however, is a rare entity.

Mycetoma clinically masquerading as squamous cell carcinoma: case report and literature review.

Mycetoma is a chronic and progressive subcutaneous granulomatous infection characterized by painless swelling and tumefaction, draining sinus tracts, and purulent discharge. The term eumycetoma is used to describe an infection caused by fungi, while an actinomycetoma is used to describe an infection caused by filamentous bacteria. An accurate identification of the pathogen plays a vital role in the treatment plan as well as a positive outcome for the patient.

Dermatofibrosarcoma protuberans: a case report and review of the literature.

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing fibrohistiocytic neoplasm that commonly favors young to middle-aged adults. It is most commonly seen on the trunk and frequently recurs locally after an incomplete excision, but distant metastasis is rare. Mohs micrographic surgery (MMS) is the treatment of choice for DFSP.

Primary mucinous carcinoma with direct histopathologic evidence of lymphatic invasion.

Background: Primary mucinous carcinoma of the skin is a rare sweat gland neoplasm which occurs most commonly in the periorbital region. Although the tumor has a propensity for local recurrence and regional spread, distant metastases are rare. The standard treatment of primary mucinous carcinoma is wide local excision.

Possible role of the bulge region in the pathogenesis of inflammatory scarring alopecia: lichen planopilaris as the prototype.

Background: Lichen planopilaris (LPP) is the prototype of scarring alopecias that mainly target the infundibuloisthmic (bulge) region of hair follicle. Hair follicle stem cells have been shown to reside in the bulge.

Methods: We carried out this study to better define the possible pathogenetic role of the bulge in LPP.

Infantile granular parakeratosis: recognition of two clinical patterns.

Granular parakeratosis is an acquired, idiopathic disorder of keratinization typified by retention hyperkeratosis. It usually occurs in women at intertriginous sites. There have been only 2 reports of infants with granular parakeratosis to our knowledge.

Early delayed-type hypersensitivity eosinophil infiltrates depend on T helper 2 cytokines and interferon-gamma via CXCR3 chemokines.

We investigated the role of T helper (Th)1- and Th2-type cytokines in delayed-type hypersensitivity to soluble protein antigens elicited early postimmunization. Mice were sensitized by intradermal injection without adjuvants, or subcutaneously with complete Freund's adjuvant, and subsequently ear challenged intradermally. As soon as day 3, antigen-specific eosinophil-rich responses were elicited in wild-type mice, but not in T-cell receptor-alpha-/- mice without adjuvant.

Verrucous plaque on the foot.

Amelanotic melanoma can present clinically in multiple ways, often mimicking benign processes. This makes diagnosis more difficult and often delays proper medical attention. This case report highlights the importance of having a high suspicion of melanoma in cases that do not behave clinically as expected.