Prostate adenocarcinoma is the most common carcinoma in men. Cutaneous metastasis of prostate adenocarcinoma, however, is rare, accounting for less than 1% of metastatic cutaneous carcinomas. This cutaneous spread most often occurs in the inguinal area and the penis, followed by the abdomen, head and neck, chest, extremities, and back. Metastatic prostate adenocarcinoma generally has a poor prognosis, emphasizing the importance of timely identification. We report a patient with an unusual clinicopathologic presentation of metastatic prostate adenocarcinoma manifesting as a scaly plaque on the left shin. This lesion was histopathologically characterized by marked epidermotropism, squamous differentiation, and acantholytic features, with a negative reaction to prostate-specific antigen and prostatic acid phosphatase immunostains. When evaluating metastatic cutaneous carcinomas displaying epidermotropism and squamoid appearances or squamous differentiation, it is essential to maintain a high index of suspicion and inquire about a history of prostate carcinoma. This history is especially relevant if hormonal therapy was utilized as part of the patient's management.
Intravascular large B-cell lymphoma (IVLBCL) is an uncommon and aggressive subtype of non-Hodgkin lymphoma defined by the proliferation of large malignant B cells confined within small blood vessels. This neoplasm can present with different nonspecific symptoms, including fever, altered mental status, livedoid skin rashes, hepatosplenomegaly, and cytopenias, often complicating its diagnosis. The main categories are classical (formerly designated as Western), hemophagocytic variant (formerly designated as Asian), and primary cutaneous IVLBCL. A distinctly severe manifestation is hemophagocytic lymphohistiocytosis (HLH), a hyperinflammatory syndrome characterized by exaggerated immune activation and macrophage activation manifested by phagocytosis of hematopoietic cells including neutrophils, red blood cells, and platelets. We describe a 72-year-old female who presented with features reminiscent of an autoinflammatory syndrome including fever and hyperferritinemia followed by clinical features concerning for HLH. She developed a reticulated skin rash. Following skin biopsy, a diagnosis was rendered of IVLBCL complicated by HLH. The pathophysiology and other aspects of the literature pertaining to IVLBCL and HLH are reviewed.
Langerhans cell histiocytosis (LCH) is a rare malignancy marked by clonal proliferation of Langerhans cells, with BRAF V600E mutations identified in over 50% of the cases. BRAF inhibitors (BRAFi), such as dabrafenib, have shown efficacy in treating BRAF V600E-mutant LCH. However, BRAFi therapy is associated with cutaneous adverse effects, including the development of new melanocytic nevi, verrucae, and keratinocyte carcinoma (KC). This case report describes a 78-year-old woman with BRAF V600E-mutant LCH who developed multiple dermatologic side effects following dabrafenib salvage therapy. Seven weeks into treatment, the patient presented with eruptive palmoplantar nevi, verrucae, and a basal cell carcinoma (BCC). Biopsies revealed endophytic verruca vulgaris and acral junctional melanocytic nevus. A previous history of KC and photodamage likely contributed to the development of BCC. Additionally, the patient experienced arthralgias and Dupuytren’s contracture, consistent with known BRAFi side effects. While the cutaneous manifestations observed here have been documented in BRAF V600E-mutant melanoma, this case is unique in its presentation in LCH patients. This report emphasizes the need for routine dermatologic monitoring and awareness of potential skin malignancies and other side effects in adults undergoing BRAFi therapy for LCH.
A 78-year-old Japanese man with a scar-like sacral lesion was referred to our hospital due to a red tumor that had developed in the region. Pathological examination of a partial skin biopsy revealed cutaneous SCC. The SCC was regarded as “a Marjolin ulcer” because the tumor developed on a chronic scar. After his first surgery, the tumor had recurred in his sacral region. He underwent a second surgical procedure; however, metastases developed in his inguinal lymph nodes. He was started on nivolumab therapy for four cycles; however, he developed local recurrence in the sacral region. He subsequently underwent local radiotherapy to the recurrent sacral lesion. After completion of local RT, nivolumab was continued for two additional cycles. Two months after his RT, his lymph node metastases surprisingly regressed, although direct radiation was not administered to his inguinal lymph nodes. The present case represents the first reported instance of cutaneous SCC (Marjolin ulcer) in the sacral region treated with nivolumab and RT in which an abscopal effect was observed.
Leukemia cutis with predilection for sites of prior cutaneous trauma, often described as a Koebner-like phenomenon, is a rare but recognized occurrence. We present a unique case of an, otherwise, healthy male who developed leukemia cutis at a prior unrelated biopsy site, leading to a new diagnosis of acute myeloid leukemia (AML). Certain AML subtypes with extramedullary propensity, particularly M4 and M5, as seen in our patient, are associated with an increased risk of leukemia cutis. Unlike their medullary counterparts, extramedullary AML cells preferentially migrate to and persist in tissues outside the bone marrow, where the local microenvironment may promote immune escape. Although the localization of leukemia cutis to the biopsy site is consistent with a Koebner-like response, it remains uncertain whether subclinical leukemic cells were already present at the time of the initial excision; therefore, a definitive causal relationship between trauma and leukemic infiltration cannot be established. Additionally, the prior keratoacanthoma and its excision may have created a localized immunocompromised cutaneous district, or locus minoris resistentiae, further predisposing the site to leukemic cell infiltration. The immunologic features of extramedullary AML, including impaired antigen presentation and T-cell exhaustion, overlap with this concept of localized immune dysregulation and may have facilitated site-specific leukemic infiltration. New infiltrative plaques at sites of prior skin trauma or biopsy warrant prompt biopsy and histopathological evaluation, even in patients without known hematologic malignancy. Leukemia cutis may represent the first manifestation of underlying acute leukemia, making early recognition critical for timely oncologic referral and treatment.
Lichen planopilaris (LPP) is a rare, immune-mediated cicatricial alopecia characterized by perifollicular erythema, hyperkeratosis, and progressive hair follicle destruction, leading to permanent hair loss. While LPP typically affects the scalp and is classified into classic LPP, frontal fibrosing alopecia (FFA), and Graham-Little-Piccardi-Lassueur (GLPL) syndrome, atypical presentations involving extra-scalp regions, including the face, are exceedingly rare. We present a unique case of melasma-like LPP manifesting on the face, a highly unusual presentation that posed diagnostic challenges due to its resemblance to hyperpigmentary disorders. A 38-year-old man presented with an asymptomatic hyperpigmented patch on the cheek and forehead mimicking melasma. This case highlights the importance of considering LPP in the differential diagnosis of facial hyperpigmentation, particularly when conventional therapies for melasma fail. It should be noted that histopathology was a valuable tool for the diagnosis of the disease. We recommend including dermoscopic images in future studies to help dermatologists become familiar with the dermoscopic features of LPP and to differentiate between LPP and melasma using dermoscopy.
Primary cutaneous T-cell lymphomas (pCTCLs) are a heterogeneous group of rare clonal T-cell disorders, among which mycosis fungoides (MF) is the most common subtype. Several clinicopathologic variants of MF have been described, including poikilodermatous and hyperpigmented forms, with occasional overlap between variants. We report a 68-year old man with a 25-year history of slowly progressive, asymptomatic dark plaques involving the lower extremities and intergluteal fold consistent with overlapping hyperpigmented and poikilodermatous MF. Unlike the classically reticulated appearance of poikilodermatous MF, the lesions displayed extensive, sharply demarcated confluent hyperpigmentation. 18F-FDG PET/CT demonstrated no systemic involvement, although the cutaneous lesions displayed mild hypermetabolism. Histopathological examination revealed epidermotropic atypical lymphocytes with superficial dermal lymphohistiocytic infiltrates, vascular ectasia, erythrocyte extravasation, hemosiderin deposition, and dermal melanophages. Immunophenotypic studies supported the diagnosis of MF with monoclonal T-cell receptor rearrangement. Disease staging was T2N0M0B0 (Stage IB). Given the longstanding indolent course, absence of symptoms, and lack of extracutaneous disease, a watch-and-wait strategy was adopted. Although hyperpigmentation may be observed in poikilodermatous MF, the unusually marked and confluent pigmentation in our patient exceeded the degree typically associated with poikiloderma alone, suggesting overlap with the hyperpigmented variant of MF. This case highlights the importance of careful clinicopathologic correlation in atypical pigmentary presentations of MF.
Confluent and reticulated papillomatosis (CRP) is a rare acquired keratinization disorder. We report a 29-year-old woman with a 3-year history of mildly pruritic hyperpigmented papules on the back, flanks, abdomen, and groin, coalescing centrally into plaques with a peripheral reticulated pattern. Dermoscopy showed a cerebriform sulci-and-gyri-like network. LC-OCT revealed a markedly thickened hyperreflective stratum corneum, increased epidermal thickness, and a strongly undulated dermal-epidermal junction; a hyperreflective basal band may also be appreciable if consistently visible on the image set. Histopathology showed orthokeratotic hyperkeratosis, focal acanthosis, papillomatosis, and increased basal pigmentation, confirming the diagnosis of CRP. In this case, LC-OCT identified in vivo optical features corresponding to key histopathologic criteria of CRP and may support noninvasive clinicopathologic correlation.
Eczema herpeticum (EH) is a superimposed cutaneous viral infection that occurs in the context of preexisting dermatoses, most commonly atopic dermatitis (AD). It typically involves the face, neck, and upper trunk. Although ocular involvement is relatively uncommon, it may present diagnostic and therapeutic challenges and pose a significant risk to vision. We report a pediatric case of EH with severe ocular involvement in a young child with underlying AD. Despite early oral antiviral and antibiotic therapy, the condition progressed rapidly to orbital cellulitis. Clinical improvement was observed following escalation to intravenous antiviral therapy, addition of topical antiviral treatment, and broadening of antibiotic coverage, with subsequent full recovery. This case highlights the importance of early recognition, close monitoring, and timely escalation of treatment in EH with ocular involvement to prevent sight-threatening complications.
A 52-year-old woman presented with a three-month history of pruritic scaly palmoplantar eruptions that progressed to tense bullae over trunk and extremities along with genital mucosal involvement. Serology confirmed syphilis (VDRL reactive at 1:16 and TPHA positive), and biopsy with direct immunofluorescence (DIF) established bullous pemphigoid (BP). Treatment with benzathine penicillin led to resolution of palmoplantar and genital lesions, but there was no improvement of bullous lesions. Treatment with oral doxycycline and prednisolone significantly resolved the bullous eruptions. In adults, secondary syphilis can rarely be present as bullous eruptions, which may mimic autoimmune blistering disorders like BP, thereby posing a diagnostic dilemma. This case uniquely demonstrates BP persisting despite successful syphilis treatment (8-fold VDRL decrease), requiring ongoing immunosuppression. Unlike previously reported cases where bullous lesions resolved with antibiotics alone, this differential response confirms that syphilis can trigger independent, self-sustaining autoimmune bullous disease.
Lymphangioma circumscriptum (LC) is a rare benign lymphatic malformation of deep dermis and subcutaneous layer. Although it commonly affects the trunk, axilla, thighs, and oral cavity, its appearance in the scrotum is extremely rare and can lead to considerable psychological distress, often due to concerns regarding sexually transmitted infections. We present a case of a 42-year-old married Nepali male who presented with multiple slow-growing, fluid-filled, grouped vesicular lesions on the scrotum that had gradually increased over 12 years. The diagnosis of LC was confirmed through clinical evaluation and histopathological findings. The patient was counseled regarding the condition and was referred for surgical management.
Aseptic and alopecic nodules of the scalp (AANS) is a rare, likely underrecognized, nonscarring alopecia characterized by one or more alopecic nodules without evidence of microbial infection. AANS has a favorable prognosis and often responds well to treatments such as doxycycline, intralesional steroids, or drainage. We present a case of AANS in a young female with a history of biopsy-proven alopecia areata that achieved full resolution without recurrence with intralesional steroids. Recognition of this rare condition, including in the setting of other established alopecia diagnoses, may avoid a missed diagnosis as well as unnecessary surgery.
Pityriasis lichenoides chronica (PLC) is a chronic cutaneous disorder of unknown cause that is thought to be a proliferation of T-cells in response to an antigen or infection. We introduce a case of a 62-year-old female who presented with an erythematous nonpainful eruption of well-demarcated annular and polycyclic papules and plaques with fine whitish peripheral scale distributed on the back, shoulders, chest, arms, and legs. Skin biopsy was consistent with PLC. After minimal improvement with systemic and topical corticosteroids, oral upadacitinib 15 mg once daily was started. Following 1 month of treatment with oral upadacitinib, the complete remission of PLC was observed. Thus, upadacitinib as a Janus kinase (JAK) inhibitor may be a novel treatment for PLC. However, more studies are needed to explore the efficacy and safety of JAK inhibitors for lichenoid disorders, such as PLC and others.
Background Inherited epidermolysis bullosa (EB) is a rare group of monogenic disorders causing skin fragility. Junctional EB is the rarest subtype, caused by mutations in genes like COL17A1. Type 1 diabetes mellitus (DM) is a polygenic autoimmune disease. The co‐occurrence of a primary structural genetic defect and a systemic autoimmune disorder is rare. This case represents a second rare co‐occurrence of EB and type 1 DM in a pediatric patient and the first reported case in the intermediate junctional EB subtype. Case Presentation We report a case of a 3‐year‐old male with a known history of intermediate junctional EB, confirmed by whole exome sequencing to be a homozygous pathogenic frameshift mutation in COL17A1. He presented with polyuria and was later diagnosed with type 1 DM. Conclusion This report highlights the importance of recognizing systemic comorbidities in patients with rare structural genetic diseases like junctional EB.
Staphylococcal scalded skin syndrome (SSSS) is a rare, toxin-mediated dermatosis in children that can mimic bullous impetigo or other severe blistering disorders. We report a 4-year-old boy presenting with fever, erythema, painful skin lesions, and conjunctivitis. Initial therapy with intravenous amoxicillin/clavulanic acid was ineffective, and progression to diffuse erythema, desquamation, and a positive Nikolsky sign led to the diagnosis of SSSS. Wound cultures grew Staphylococcus aureus, and escalation to intravenous cloxacillin, combined with supportive care including hydration, analgesia, and skin management, resulted in rapid clinical improvement. The patient was discharged after 10 days with complete recovery and no complications. This case highlights the diagnostic challenge of SSSS and underscores the importance of early recognition and prompt, targeted antistaphylococcal therapy. Supportive management is crucial to prevent serious complications and ensure favorable outcomes in pediatric patients.
Childhood eczema is a chronic inflammatory skin condition affecting up to 20% of children worldwide. Characterized by itchy, red, and inflamed skin, eczema often disrupts sleep, causes emotional distress, and impacts development. This case report explores the potential of nutritional therapy in managing severe eczema symptoms in an 11-year-old boy, which had been unresponsive to standard treatments. The intervention involved eliminating ultra-processed foods, reducing refined carbohydrates, and supplementing with vitamin D, fish oil, and propolis. Over a year, the patient showed significant improvement, with resolution of erythema, scaling, and lichenification across affected areas, including the back, lower extremities, hands, and elbows. The results suggest that a diet emphasizing minimally processed foods, combined with anti-inflammatory supplements, may help control eczema by modulating inflammation and supporting skin barrier function. This case supports further research into dietary modifications as an adjunctive therapy for managing eczema in children.
Linear immunoglobulin A (IgA) bullous dermatosis (LABD) is a rare autoimmune neutrophilic dermatosis that can mimic viral or molluscoid eruptions, thereby delaying treatment. We report a 2-year-old girl with a 2-week history of pruritic vesiculobullous rash that began as a single “mosquito bite.” Multiple emergency department visits led to empiric acyclovir and topical steroids. Histopathologic confirmation of LABD, essential for diagnosis, was achieved by a skin biopsy performed on Day 8, which revealed a subepidermal bulla with 3+ linear IgA deposition at the dermoepidermal junction. She improved after dapsone dosed daily at 1 mg/kg−1, plus a tapering course of prednisolone. Therefore, early consideration of LABD in toddlers with disseminated evolving vesicular lesions can prevent unnecessary treatments and expedite more targeted immunosuppressive therapy.
Introduction:Secondary intention healing (SIH) in the nasal region yields variable cosmetic results depending on the involved subunit. We report a case of a recurrent sclerodermiform basal cell carcinoma (BCC) resulting in an extensive surgical defect involving multiple subunits of the nose, eyelid, and cheek, traditionally requiring complex multistage flap reconstruction, successfully managed with SIH followed by a combination of laser technologies. Case presentation:A 75-year-old male with recurrent sclerodermiform BCC underwent excision resulting in a large facial defect affecting multiple nasal, eyelid, and cheek subunits. The wound was managed with SIH supported by sequential use of advanced dressings. After several weeks, the patient developed a small hypertrophic scar along the lateral nasal sidewall and malar region. A combined protocol using intense pulsed light (IPL), a fractional ablative erbium laser, and 5-fluorouracil (5-FU) drug delivery resulted in progressive remodeling and complete clinical resolution of the hypertrophic component, yielding a nearly imperceptible scar. Discussion:Early postoperative intervention with a multimodal laser approach may significantly enhance cosmetic outcomes following SIH, even in extensive defects involving multiple facial subunits. This case illustrates the potential of combined laser technologies and 5-FU as a minimally invasive strategy to optimize scarring and reduce the need for complex reconstructive surgery.
Cutaneous tuberculosis (CTB) is a rare manifestation of extrapulmonary tuberculosis that is frequently misdiagnosed due to its diverse clinical presentation and resemblance to other dermatological conditions. Tuberculosis verrucosa cutis (TBVC), one clinical manifestation of CTB, poses a particular diagnostic challenge, as lesions are often paucibacillary, resulting in negative culture and PCR results. We present the case of a 73-year-old woman with a 10-year history of recurrent skin lesions on her left hand, initially diagnosed as eczema and exacerbated by topical corticosteroid treatment. Despite repeated negative histopathological stains, mycobacterial cultures. and PCR for Mycobacterium tuberculosis, a strong positive QuantiFERON-TB Gold test established the diagnosis. This case emphasizes the diagnostic utility of interferon-gamma release assays (IGRAs) in paucibacillary forms of CTB. Management was complicated by adverse drug reactions (ADRs) to first-line antituberculosis therapy (HRZE), including myalgias, fatigue, and a pruritic rash attributed to pyrazinamide and rifampin. These agents were discontinued, and the patient was transitioned to an alternative regimen, which resulted in improved tolerability and marked clinical improvement. This case highlights the diagnostic pitfalls and therapeutic challenges in managing TBVC. It underscores the importance of maintaining a high index of clinical suspicion for CTB in chronic, verrucous skin lesions, even in patients without specific TB risk factors. It also emphasizes the need for individualized treatment strategies.
