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.

Diagnostic application of cyclin D1 fluorescent in situ hybridization for histologically undetermined early lesions of acral melanoma in situ: A case series.

Histologically undetermined early acral melanoma in situ (HUAMIS) is rare but a diagnostic challenge, being clinically and dermoscopically MIS (late onset, a large size (>7 mm), parallel ridges pattern) but microscopically without recognizable cytological atypia. Cyclin D1 (CCND1) gene amplification is a genetic aberration occurring in the early radial growth phase of AMs and could thus help determine malignancy for this disease. We determine the value of CCND1 amplification by FISH as a diagnostic marker for HUAMIS. CCND1 amplification was examined in paraffin-embedded skin biopsies and excisions using a dual-probes fluorescence in situ hybridization (FISH) (11q13 and CEP11). One FISH-negative case 6 was additionally examined by Mypath Melanoma (qRT-PCR). Seventeen cases (12 dysplastic nevi, 3 AMIS, and 2 invasive AM) were served as negative controls for FISH. All six patients (4 females and 2 males) were Hispanic. Pigment lesions were on the left plantar foot (4), right third finger palm (1), and right thumb subungual (1). All cases showed similar clinical and dermoscopical characteristics, including late onset (50 to 74 years old), long duration (from 2 to 15 years), large-sized pigments (from 16 to 40 mm), and a parallel ridge pattern. Junctional melanocytes with no or minimal atypia from five cases showed CCND1 amplifications. Four of 5 cases were received 1st or/and 2nd wide excisions, which demonstrated foci of histologically overt MIS. One FISH-negative case 6 demonstrated "likely malignancy" scores (>2) by Mypath Melanoma (qRT-PCR). None of negative controls showed the amplification. We propose here a simple CCND1 FISH is a practical diagnostic test to determine the malignancy of the very early progression phase of AM preceding histopathologically defined MIS. Cases presented here could be an indolent subtype of AMIS characterized by carrying a long latent radial growth phase without vertical growth, mimicking lentigo maligna.

Blue Nevi of the Ocular Surface: Clinical Characteristics, Pathologic Features, and Clinical Course.

PURPOSE: Blue nevus is a melanocytic tumor that is commonly found in the skin. Extracutaneous presentations, including the ocular surface, are rare. As such, the purpose of this study was to characterize the clinical features and clinical course of congenital melanocytic tumor (blue nevus) of the conjunctiva. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-one patients with 23 blue nevi of the ocular surface that were excised surgically between 2000 and 2016. METHODS: Chart review of patients identified from a database search of the Florida Lions Ocular Pathology Laboratory records. Pathologic diagnoses were confirmed by 2 pathologists (S.R.D. and G.E.). All specimens were bleached and, tissue permitting, stained using SOX10 (MilliporeSigma, Darmstadt, Germany) and CD68 (Leica Biosystems, Nussloch, Germany). MAIN OUTCOME MEASURES: Clinical characteristics, pathologic features, and clinical course. RESULTS: Mean age of the population was 55±15 years; 71.4% (n = 15) were white and 57.1% (n = 12) were men. One patient had 3 lesions, for a total of 23 lesions examined. Clinically, 13 lesions were on the bulbar conjunctiva, 3 were on the tarsal conjunctiva, 3 were in the fornix, 2 were caruncular, 1 was episcleral, and 1 was at the limbus. Before excision, 8 patients were thought to have primary acquired melanosis, 4 with concern for primary conjunctival melanoma, and 1 thought to have metastatic disease from a plantar melanoma. Five lesions were thought to be benign, and in 8 patients, the lesions were identified incidentally after other ocular surgeries, with no diagnosis of the lesions before excision. Pathologic features were consistent with simple blue nevi in 21 lesions and cellular blue nevus in 2 lesions. No malignant transformations were noted in any patient over the mean 20.2-month follow-up period (range, 2 weeks-103 months). CONCLUSIONS: Blue nevus is a rare deeply pigmented congenital melanocytic lesion with a benign clinical course that can appear clinically similar to primary acquired melanosis or melanoma.

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.

Giant proliferating trichilemmal cyst arising from a nevus sebaceus growing for 30 years.

Nevus sebaceus of Jadassohn, a congenital cutaneous hamartoma, has the potential to develop into various epidermal adnexal-origin neoplasms. While the most common neoplasms are trichoblastoma or syringocystadenoma, proliferating trichilemmal cysts are exceptionally rare. We report a case of a 63-year-old Cuban male with a giant proliferating trichilemmal cyst arising from a nevus sebaceus on the right shoulder which had been growing for 30 years. Proliferating trichilemmal cysts arising from nevus sebaceus cases are difficult to diagnose clinically and histologically as they are very rare and have not been defined by exact diagnostic criteria. Our case creates awareness of this particular tumor in nevus sebaceus and shares clinical and histological diagnostic information that can be used to make a proper diagnosis.

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.

Is primary breast melanoma a true pathological entity? The argument against it.

Background: Previous studies have reported cases of primary melanoma of the breast parenchyma (PMBP), but the pathogenesis of this disease remains poorly understood. We review the presentation and outcomes of reported cases and provide detailed pathological analysis of four additional cases. Furthermore, we discuss potential theories regarding the pathogenesis of this clinical presentation. Results: We identified 29 published studies (n = 95 patients) and report four new cases (n = 99). Ninety-one (92 %) patients were female, with a median age of 50 years. Previous skin melanomas were reported by 56 % of patients, with the trunk being the most common location (32.7 %) followed by the upper extremities (20 %). The most common tumor location reported (n = 73) was the right (49 %) upper outer quadrant (56 %). The median time from skin melanoma diagnosis to the presence of a breast mass was 65 months (1-192). Nodal status at presentation was reported in n = 67 (68 %) patients. Of these, positive nodal metastases were seen in 40.3 %, while distant metastatic disease at presentation was reported in 30 % of patients. Surgery was performed in 66 %, being partial mastectomy (PM) the most common procedure in 82 %. Adjuvant therapy was described in 38 patients. The reported (n = 12) median survival was 11.5 (1-70) months. Conclusion: Melanomas identified in the breast parenchyma are likely the result of nodal or hematogenous spread from previously known or unknown melanomas, and should not be considered as PMBP. Management should be multidisciplinary, including surgical excision aimed at obtaining negative margins with lymphadenectomy of clinically positive nodes and neoadjuvant/adjuvant immunotherapy.

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.