Two Incidental Sibling Diagnoses of Netherton Syndrome in Separate Visits: A Case Report.

Netherton syndrome (NTS) is a genetic disorder that predominantly affects the hair and the skin, and it can have a wide variety of presentations. The genetic syndrome is more common with consanguineous parents. Given the rarity and varying presentation of the condition, a few cases have been reported in the literature. We present an unusual case of two incidental diagnoses of NTS in siblings of consanguineous parents, manifesting as erythroderma and other symptoms that were initially diagnosed as pityriasis rubra pilaris and psoriasis in separate visits. Physicians must maintain a high index of suspicion when faced with chronic skin conditions and hair shaft abnormalities that may have been present since childhood to avoid the sequela of inadvertent prolonged or misdiagnosis.

A study of collagen refractility in dermatofibroma and dermatofibrosarcoma protuberans using diffractive microscopy.

BACKGROUND: Diffractive microscopy creates contrast within samples that are otherwise uniform under bright light. This technique can highlight subtle differences in refractive indices within birefringent samples containing varying amounts of mature collagen. Dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) possess differences in their mature collagen content and, therefore, may be distinguishable using diffractive microscopy. METHODS: Two hundred forty-two DF and 85 DFSP hematoxylin-eosin (H&E)-stained specimens were analyzed using diffractive microscopy. Data regarding the distribution pattern and strength of refractility was recorded. RESULTS: DFSP was more frequently found to be focally, weakly, or non-refractile (82.9%; n = 68) under diffractive microscopy, while DF more often showed diffusely bright refractility (52.9%; n = 128). DFSP samples with diffuse refractility in portions of the lesion (17.1%; n = 14) also exhibited a unique checkerboard pattern distinct from that which was seen in DF samples. CONCLUSIONS: The absence of diffuse refractility was more closely associated with DFSP, as was the presence of a unique checkerboard diffraction pattern. Despite high sensitivity (Sn = 82.9%), absent refractility was not a specific test (Sp = 52.9%), with 47.1% (n = 114) of DF samples sharing this feature. The distinction between DF and DFSP is often diagnosed using H&E alone. In difficult cases, examination of collagen under diffractive microscopy may be useful in distinguishing DFSP from DF and provide an alternative cost-effective tool to immunohistochemical staining.

Cytologic atypia of benign inflammatory versus neoplastic cutaneous squamous lesions.

BACKGROUND: Cytologic atypia encompasses several features of abnormal cellular morphology. We sought to quantify these features in benign and premalignant/malignant squamous cell lesions to better characterize criteria for malignancy. METHODS: We conducted a rater-blinded observational study in which histopathology slides were evaluated under light microscopy, and the presence and relative quantity of 24 distinct cytological features were recorded, along with respective diagnoses. Each slide was evaluated, and the ratings were recorded and analyzed. RESULTS: The most helpful findings, whose presence in high numbers indicates an increased likelihood that the tissue sample is premalignant/malignant, were: (1) pleomorphic parakeratosis; (2) pleomorphic nuclei in the epithelium; (3) irregular nuclei; (4) thick refractile nuclear envelope; (5) presence of nuclear hyperchromasia (dark gray); (6) peripheral nucleoli; and (7) nucleolar stems. Higher values of round or oval nuclear shape and vesicular nuclei increase the likelihood that the tissue sample is benign. CONCLUSIONS: Certain nuclear features have a higher association with premalignancy/malignancy and may guide histologic evaluation of a given lesion. These findings can be used in combination with architectural features and clinical history to add to a complete diagnostic picture.

Dermatofibroma Versus Dermatofibrosarcoma Protuberans: A Nuclear Morphology Study.

ABSTRACT: The locally invasive soft-tissue sarcoma, dermatofibrosarcoma protuberans (DFSPs), shares certain histologic features of the much more common and benign dermatofibroma (DF). While immunohistochemical stains, specifically cluster of differentiation 34 and Factor XIIIa, can be used to distinguish the 2 entities using microscopy, these markers are not entirely sensitive nor specific. Three-dimensionally, DFSP nuclei resemble a "puck" or "coin"-like shape. As hematoxylin/eosin-stained slides are prepared, these "puck" nuclei are fixed in an infinite number of orientations depending on their current position in rotation about their axes within the tumor cells. Under histological examination, this random nuclear positioning produces the appearance of 2 predominate morphologies: an ovoid "disk" shape (en face) and a narrow spindled shape (side view), which distribute in a roughly 50:50 ratio throughout the tumor sample slide. Nuclear morphology was analyzed in 324 DFSP and DF samples at high magnification (×400) to determine the presence or absence of a predominant morphology in which nuclei appear to alternate between an ovoid (en face) and spindled (side view) throughout most of the tumor sample. An alternating ovoid-spindled nuclear morphology was the predominant cytology in 98% of DFSP and was not predominant in 100% of DF samples (P < 0.001). This morphology was found to be highly specific (Sp = 1) and sensitive (Sn = 0.98) for DFSP. This unique nuclear morphology may be a more sensitive and specific diagnostic tool in identifying DFSP from DF in comparison with costly immunohistochemical stains.

Characterizing Skin Cancer in Transplant Recipients by Fitzpatrick Skin Phototype.

INTRODUCTION: Nearly half of organ transplants occur annually in patients with Fitzpatrick skin phototypes (Fitz type) III-VI. Organ transplant recipients (OTRs) are at risk for sequelae of chronic immunosuppression, of which skin cancer is common. As literature regarding skin cancer risk is largely conducted in OTRs with Fitz types I and II, we aimed to further characterize the incidence and risk factors for skin cancer in OTRs with higher Fitz types. METHODS: We conducted a retrospective review of OTRs with Fitz types III-VI evaluated by dermatology between 1 January 2012 and 1 June 2022. The primary outcome of this study was development of skin cancer post-transplant. Secondary outcomes included risk factors for skin cancer development. Data were analyzed using two-sample t-tests and Pearson's chi-squared. RESULTS: Of 530 OTRs, 193 had Fitz type III or higher. Ten patients (5.18%) developed 87 skin cancers and one recurrence at a mean of 5.17 years posttransplant. Patients with skin cancer self-identified as Black (70%, p-value ≤ 0.001), male (70%, p-value ≤ 0.001), and kidney transplant recipients (70%, p-value ≤ 0.001), with a mean age of 58.20 years at transplant (p-value ≤ 0.001). Subjects with skin cancer were more likely to be former smokers (60%) and prescribed tacrolimus (p-value ≤ 0.001 each). Development of cutaneous squamous cell carcinoma (66, 75.86%) was most common, followed by basal cell carcinoma (17, 19.54%), and malignant melanoma (3, 3.45%). Skin cancer most often occurred on the face or scalp (60%, p-value = 0.027), though also developed in sun-protected sites (30%, p-value = 0.002). Verruca vulgaris was present in 10% of patients (p-value = 0.028). CONCLUSIONS: Risk factors for skin cancer post-transplant differ in OTRs with higher Fitz types. Our results suggest that among OTRs who self-identified as Black, kidney recipients are at increased risk for skin cancer in non-sun-exposed regions. These cancers may be associated with human papillomavirus (HPV). Education is key for preventing morbidity and mortality secondary to skin cancer.

Acromegaly Presenting with Resistant Acne Vulgaris.

Acne vulgaris is one of the most frequent skin diseases worldwide, triggered by multiple endogenous and exogenous factors. Hormones, particularly growth hormone (GH), insulin-like growth factor-1, insulin, CRH, and glucocorticoids, play a major role in the pathogenesis and exacerbation of acne. Excess GH seen in acromegalic patients may result in increased size and function of sweat glands and sebaceous glands, which may contribute to the patient's worsening acne and interfere with dermatologic treatment. Therefore, understanding the pathogenesis of acne will help in treating resistant acne by diagnosing and treating the underlying etiology using multidisciplinary treatment.