Cutaneous Mycobacterium avium-intracellulare infection masquerading as sarcoidosis.

Mycobacterium avium-intracellulare (MAC) infection may have different skin manifestations, including cutaneous granulomas. Granulomatous skin reactions have distinct morphologic and histopathologic appearances. We present the case of an adolescent male with cutaneous MAC, misdiagnosed as sarcoidosis after initial biopsy results, demonstrated preservation of reticulin fibers and absence of organisms within granulomas. Sarcoidal granulomas often stain positive for reticulin fibers, which could be used to distinguish them from the infectious kind. This case should alert clinicians to the fact that the presence or quantity of intact reticular fibers may not be a reliable tool to differentiate between a sarcoidal and an infectious granuloma. Our case also highlights the diagnostic challenge of cutaneous MAC infection.

Squamoid Eccrine Ductal Carcinoma of the Eyelid: Clinicopathologic Correlation of a Case.

Squamoid eccrine ductal carcinoma (SEDC) is a rare cutaneous neoplasm that often manifests as a plaque or nodule in sun-exposed areas of older patients. Herein, the authors report the first case of SEDC in the eyelid. A 76-year-old man presented with a 2.5 × 1.5 mm area of left upper eyelid erythema, thickening, ulceration, and scaling with madarosis superotemporally just above the lash line. Full-thickness wedge biopsy demonstrated irregular epithelial tubules with nuclear atypia and focal squamous differentiation, consistent with SEDC. The patient underwent Mohs resection and has had no recurrence approximately 27 months after surgical removal. The authors present this case to raise awareness of SEDC to ophthalmologists as all previous cases have been described in the nonophthalmic literature. A full-thickness biopsy is recommended to avoid misdiagnosing SEDC as squamous cell carcinoma (SCC), a less aggressive tumor. With greater awareness, there may be increased recognition of this likely underreported, more malignant entity.

Phaeohyphomycosis due to Exophiala infections in solid organ transplant recipients: Case report and literature review.

This case report and literature review underscores the cutaneous presentations of phaeohyphomycosis in the solid organ transplant population. Increased cognizance with prompt identification is critical. The therapy and clinical outcomes of phaeohyphomycosis, caused by the Exophiala genus, in the solid organ transplant population, is analyzed to examine optimal care. This review highlights the inherent difficulties in providing the appropriate duration of antifungal therapy to avoid relapsing infections in immunosuppressed patients.

Imported fire ant envenomation: A clinicopathologic study of a recognizable form of arthropod assault reaction.

BACKGROUND: Skin reactions to the sting of the imported fire ant have characteristic clinicopathological features. METHODS: One case of experimental envenomation was prospectively followed during 48 hours, with biopsies. In addition, 6 cases from our laboratory were retrospectively evaluated histopathologically for the following features: spongiosis, exocytosis (and type of cells), pustule formation, erosion/ulceration, epidermal necrosis, scale/crust, papillary dermal edema, inflammatory dermal infiltrate (cell type, density, depth, distribution, shape), red blood cell extravasation, vasculopathy and vasculitis. RESULTS: The typical lesion follows a very distinctive clinical and histopathologic evolution over 48 hours, with the formation of a subepidermal pustule overlying a wedge-shaped area of dermal collagen basophilic degeneration with scattered neutrophils. In the 6 cases retrieved from our files, the main features were a superficial and deep dermal, perivascular, periadnexal and interstitial infiltrate consisting of neutrophils, with basophilic degeneration of the collagen. A subepidermal pustule was noted in half of the cases. CONCLUSIONS: In biopsies taken in a clinical setting, even in the absence of the characteristic subepidermal pustule, the diagnosis of imported fire ant sting can be suspected if there is a superficial and deep perivascular, periadnexal and interstitial infiltrate composed of neutrophils, with some basophilic denaturation of collagen.

Subcutaneous (deep) fungal infections.

Fungal infection is a common clinical problem in dermatology. While most cases in practice are superficial infections, invasive subcutaneous mycoses are important to recognize and treat, as these conditions often have significant morbidity and mortality. Deep fungi demonstrate species-specific syndromes and may be identified by clinical and histological features in addition to serological evaluation and culture. Identification of the common innoculation subcutaneous mycoses, as well as those associated with pulmonary primary infection and dissemination to the skin is important, as treatments vary by organism and clinical setting. This overview will help to identify the key dermatological presentations of subcutaneous fungal infection, and the clues they give to cause.

Immune checkpoint inhibitor associated epidermal necrosis, beyond SJS and TEN: a review of 98 cases.

Immune checkpoint inhibitor (ICI) therapies carry the risk of major immune-related adverse events (irAEs). Among the most severe irAEs is epidermal necrosis that may clinically mimic Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN). The aim of this study was to provide a summary of the clinical and histological features of ICI-associated epidermal necrosis, with a special focus on factors associated with fatal outcomes in cases of extensive disease. A total of 98 cases, 2 new cases and 96 reported on PubMed and in the literature, of ICI-associated epidermal necrosis were assessed. Development of epidermal necrosis occurred between 1 day and 3 years after starting ICI therapy, with an average onset of 13.8 weeks for patients with limited (< 30% BSA) and 11.3 weeks for those with extensive (≥ 30% BSA) involvement, and a median onset of 5.8 weeks and 4 weeks respectively. A preceding rash was seen in 52 cases and was more common in extensive cases. Mucosal involvement was only reported in 65% of extensive cases but was significantly associated with fatal reactions. Co-administration of cytotoxic chemotherapy was associated with more extensive disease. Recovery was observed in 96% and 65% of those with limited and extensive involvement respectively and no specific therapy was associated with improved survival. Young age was significantly associated with poor outcomes in extensive disease, the average age of surviving patients was 64.5 years old versus 55.1 years old for deceased patients, p < 0.01. Both superficial perivascular and interface/lichenoid inflammatory infiltrates were commonly seen. These findings suggest that ICI-associated epidermal necrosis should be considered a distinct clinical entity from drug-induced SJS/TEN.

Conjunctival keratoacanthoma: a clinical and histopathological case series.

OBJECTIVE: To present a series of conjunctival keratoacanthomas and provide clinical, histopathological, immunohistochemical, and imaging results that characterize this rare entity. METHODS: A retrospective chart review of records from 2005 to 2023 from the Florida Lions Ocular Pathology Laboratory was conducted. Nine patients with histologically proven conjunctival keratoacanthoma were identified. Data extracted includes demographics, clinical history, diagnostic testing, histopathological and immunohistochemical testing, treatment modalities, and recurrences. RESULTS: Patients' mean age was 55.2 ± 21.1 years (range: 22-83). 77.8% (7/9) of patients were male. 55.6% (5/9) were Hispanic. 55.6% of lesions (5/9) were in right eyes. 55.6% of lesions (5/9) were on the temporal, bulbar conjunctiva. The lesions were rapidly growing, with mean onset time of 4.71 ± 3.30 weeks (range: 2-12). High-resolution anterior segment optical coherence tomography of three lesions revealed hyper-reflective, thickened epithelium with abrupt transition between normal and abnormal epithelium. Underlying disorganized subepithelial tissue was noted. However, the overlying abnormal epithelium caused considerable shadowing, which obscured subepithelial structures. Prominent, keratin-filled, cup-shaped lesions with faulty maturational sequencing that extend full thickness, variably pale cytoplasm, and foci of dyskeratosis and hyperkeratosis were present on all lesions' histopathology. All lesions were surgically excised, but two demonstrated partial spontaneous resolution before surgery. Two patients were lost to follow-up; the remaining seven had no signs of recurrence at a of mean of 36.9 ± 45.4 months (range: 3 to 141 months) of follow-up. CONCLUSIONS: Conjunctival keratoacanthomas are rare lesions of the ocular surface with distinct clinical, histopathologic, and diagnostic features.

Autoreactive T cells in the immune pathogenesis of pemphigus vulgaris.

Pemphigus vulgaris is a life-threatening autoimmune blistering disease caused by anti-desmoglein IgG autoantibodies that finally lead to acantholysis presenting clinically as progressive blistering. Whilst the production of pathogenic antibodies is key to the development of pemphigus vulgaris, many immunological steps are required prior to autoantibody induction. We review advances in the understanding of these immunologic processes with a focus on human leucocyte antigen polymorphisms and antigen recognition, epitope spreading, central and peripheral tolerance, T helper differentiation, induction of pro- and anti-inflammatory cytokines and T-cell regulation of B cells. Targeting autoaggressive T cells as regulators and stimulators of B-cell antibody production should allow for more specific therapeutic immune interventions, avoiding the global immunosuppression seen with many commonly used immunosuppressants in pemphigus vulgaris.

Atypical form of transient reactive papulotranslucent acrokeratoderma in a cystic fibrosis carrier.

We report the first documented case of an atypical form of transient reactive papulotranslucent acrokeratoderma (TRPA) in a patient heterozygous for the ΔF508 CFTR(cystic fibrosis transmembrane conductance regulator) mutation. TRPA represents a condition that classically presents with translucent to white plaques that become evident after water exposure. An atypical form with persistent lesions has also been described. Our patient is a 16-year-old girl with small, white papules coalescing into pebbly plaques on the palms. This condition is exacerbated after 5-10 min of water exposure and is associated with discomfort. The skin biopsy showed expanded stratum corneum, orthohyperkeratosis and dilation of eccrine ducts consisting with TRPA. A cystic fibrosis carrier state, barrier function defect, hyperhidrosis and the intake of cyclooxygenase inhibitors may have been pathogenic factors in our patient.

Coma blisters in two postoperative patients.

Coma blisters are self-limited cutaneous bullae that occur in the setting of loss of consciousness because of a drug, illness, or accident, with the most common settings being barbiturate overdose and neurological disorders. The etiology behind coma blisters is poorly understood and is not related to underlying infections or autoimmune conditions. The clinical presentation consists of bullae, erosions, and violaceous plaques usually involving sites of pressure. The skin lesions usually occur within 48-72 hours of the start of a coma and resolve within 2-4 weeks. We present one case of a 5-month-old infant with severe valvular disease who required surgical repair. He was placed on extra corporeal membrane oxygenation and developed multiple tense coma blisters during the course of therapy. Skin biopsy revealed a noninflammatory subepidermal blister with necrosis of the overlying epidermis and necrosis of the eccrine ducts. We also present a second case of an 18-year-old female patient who underwent surgical resection of a benign mandibular tumor. She subsequently developed bullae on both arms 4 days after surgery. The skin biopsy showed a necrotic epidermis, a subepidermal blister, and diffuse necrosis of the eccrine coils.

Congenital idiopathic atrophoderma of Pasini and Pierini.

Idiopathic atrophoderma of Pasini and Pierini is a disorder of dermal atrophy. There is a female predominance and almost never does the condition present at birth. Histopathological examination reveals attenuated dermis. We report a case of a healthy male born with a plaque of idiopathic atrophoderma of Pasini and Pierini.

Cutaneous endometriosis: diagnostic immunohistochemistry and clinicopathologic correlation.

Endometriosis is a condition where endometrial glands and stroma are ectopically located in sites other than the uterine cavity. Cutaneous endometriosis is very rare, representing approximately 1.1% of cases of extrapelvic endometriosis. We report a case of a 44-year-old female with no prior surgical history who presented with multiple tan brown periumbilical nodules. Histopathological examination revealed multiple glandular structures in the dermis with surrounding stroma. Immunohistochemistry cinches the diagnosis, as CD10, estrogen receptor and progesterone receptor are strongly positive in our case. The mainstay of treatment of cutaneous endometriosis is surgical excision of the lesion.

The pulsed dye laser for the treatment of basal cell carcinoma.

Basal cell carcinomas (BCC) have a specialized microvasculature system that can be targeted by the 585-nm pulsed dye laser (PDL) utilizing the theory of selective photothermolysis. Seven volunteers with nine well-defined, biopsy-proven BCCs, were treated with the PDL (585-nm wavelength, a single 450-µs pulse, 7-mm spot size, and 9.0 J/cm(2) energy). The lesions, along with a 4-mm border of normal skin were treated. Pain assessment was carried out immediately after the laser treatment. A deep shave biopsy with histological examination occurred 4 weeks after the laser treatment. Pain was assessed on a scale of 0 (no pain) to 10 (worst pain possible). The average patient score was 2.1 (range 1-4). On histology, 5/9 (55.6%) sites demonstrated no evidence of BCC; however, 4/9 (44.4%) sites showed residual BCC. Although the PDL was able to clear over half of the BCCs in this study, there was an unacceptably high persistence rate of 44.4%. The PDL did not achieve the clearance rate that can be attained with current standard BCC treatment modalities. At this time, we do not recommend that a single treatment with the 585-nm PDL can be used as a primary therapy for BCC.

Comparison of the effectiveness of the pulsed dye laser 585 nm versus 595 nm in the treatment of new surgical scars.

UNLABELLED: The aim of this study was to compare the effects of the pulsed-dye laser (PDL) at a wavelength of 585 nm with those at 595 nm in the treatment of post-surgical scars, starting on the day of suture removal. The study was a prospective, non-randomized, double-blind, controlled, clinical trial, set in an outpatient clinic. Fifteen outpatients with 21 post-operative scars at least 3 cm long were recruited, and 14 patients with 19 scars completed the study. Scars were divided into three equal portions. Each outer portion was randomly allocated to PDL at 585 nm or at 595 nm (3.5 J/cm(2), 450 micros, 10 mm spot size), and the center was an untreated control; treatment was composed of three laser sessions at 4-week intervals. A blinded examiner evaluated the three scar sections using the Vancouver scar scale for pigmentation, vascularity, pliability, and height. Cosmetic appearance was evaluated with a visual analog scale. Punch biopsies of three randomly selected scars were evaluated. Pigmentation: more scars after laser treatments were of normal color than in the control, but the difference was not statistically significant. Vascularity: after treatment, more scars had normal vascularity in all three groups than at baseline (P < 0.05); the largest increase was with a wavelength of 585 nm (10.5-94.7%), then 595 nm (15.8-78.9%), then control (5.2-36.6%). Pliability: there was more normal pliability in all three groups than at baseline (P < 0.05), with greater improvements in the laser-treated groups. Height: significantly more flat scars after 585 nm PDL (63.2%) than at baseline (21.1%) (P < 0.05). We observed a slight but non-significant decrease in the scar heights with 595 nm PDL in comparison with the control. HISTOLOGY: after laser irradiation, the treated sections were more similar to a non-scarring process than the control. Cosmetic outcome: visual analog scales increased in all groups (P < 0.05), but the greatest increases were observed in the 585 nm and 595 nm laser-treated groups (50% and 60%, respectively) compared with controls (30%). There were significantly higher scores with the lasers than for the control (P < 0.001) at each visit after baseline. Both the 585 nm and 595 nm PDL treatments were effective in improving the appearance and normalizing the vascularity and pliability of post-operative scars. Both wavelengths improved the scars' visual appearance more than controls. We found that 585 nm appears to be the preferred wavelength, as it substantially normalized the height in addition to the vascularity and pliability in a significant number of scars.