A Newborn Female with a Diffuse Rash.

Langerhans cell histiocytosis is a rare and clinically heterogeneous group of dendritic histiocytic disorders with typical onset in the neonatal period or infancy, although it can present at any age. Histiocytes accumulate in one or more organs, leading to a variable clinical presentation of disease. We report a case of biopsy-proven Langerhans cell histiocytosis in a newborn and discuss the workup and management of this disease, along with reviewing its clinical variants.

Importance of universal mismatch repair protein immunohistochemistry in patients with sebaceous neoplasia as an initial screening tool for Muir-Torre syndrome.

Muir-Torre syndrome, a Lynch syndrome variant, is characterized by sebaceous neoplasia plus one or more malignancies, typically colon cancer. The significance of DNA mismatch repair (MMR) deficiency detection by immunohistochemistry (IHC) in colorectal carcinomas is well established and is recommended as a screening tool for Lynch syndrome in newly diagnosed colorectal carcinomas. In comparison, literature on IHC application to detect MMR proteins (MLH1, MSH2, MSH6, and PMS2) in sebaceous neoplasia has been less studied and has been derived almost exclusively from tertiary care centers. Herein we describe the largest series to date characterizing MMR deficiency in sebaceous neoplasms, as well as the relative frequencies of each deficiency. Two hundred sixteen consecutive sebaceous neoplasms (216 patients) were analyzed from a community practice setting (133 sebaceous adenomas, 68 sebaceomas, 15 sebaceous carcinomas). One hundred forty-three were MMR deficient (66%), of which 90 were MSH2/MSH6 deficient (63%), 27 MLH1/PMS2 deficient (19%), 22 MSH6 deficient (15%), and 4 PMS2 deficient (3%). MMR deficiency was significantly associated with site, with tumors off of the head and neck more likely to be MMR deficient (specificity 96%). In contrast to prior reports, no significant trend in MMR-deficient versus -nondeficient tumors was seen in age at presentation (median age, 68 versus 66), tumor-infiltrating lymphocytes, or tumor type. Given the low sensitivity of age < 60 years (30%), location off of the head and neck (41%), or presence of tumor-infiltrating lymphocytes (29%) in MMR deficiency detection, IHC screening programs should test all sebaceous neoplasms for MMR deficiency, regardless of their clinicopathological features.

Cutaneous clues to renal cell carcinoma: hereditary leiomyomatosis and renal cell carcinoma.

We present a case of a 33-year-old female who was incidentally found to have cutaneous leiomyomata during a routine skin examination. Further history revealed that she also suffered from uterine fibroids and that her mother had died at an early age from renal cell carcinoma. This case serves as a reminder of the often-subtle cutaneous clues, as well as the importance of a multidisciplinary approach, for early diagnosis of potentially fatal conditions.

Histopathology of vascular anomalies.

Vascular anomalies may be appropriately classified into two broad categories, vascular tumors and vascular malformations, which are distinguished by the presence of cellular proliferation in contrast to aberrations in morphogenesis, respectively. This system of classification is based upon histological features that may in large part be differentiating, but nevertheless, may show morphological overlap. Advances in immunophenotyping allow for more precise diagnoses as well as further delineation of cell origins. In the discussion, we present the clinical, histological, and, when applicable, the immunophenotypic presentation of vascular anomalies commonly seen in infancy and early childhood.

Primary cutaneous amyloidosis of the external ear: a clinicopathological and immunohistochemical study of 17 cases.

Primary cutaneous amyloidosis includes several forms of localized amyloidosis characterized by superficial amyloid deposits occurring at or near the dermal-epidermal junction in the absence of systemic involvement. Primary cutaneous amyloidosis of the auricular concha and external ear represents a rarely described variant. There have been 27 cases reported in the English language literature, and herein we report 17 additional cases. This article demonstrates that the amyloid observed in this context is generally positive for Congo red, crystal violet and thioflavin T. It also expresses cytokeratin 34ßE12 via immunohistochemistry. Our immunohistochemical results and review of the literature suggest that the amyloid in amyloidosis of the external ear is the result of basal keratinocyte degeneration and does not signify deposition from a systemic or generalized process.

De novo intraepidermal epithelioid melanocytic dysplasia: a review of 263 cases.

BACKGROUND: De novo intraepidermal epithelioid melanocytic dysplasia (DNIEMD) is a newly characterized lesion that is associated with a personal and/or family history of malignant melanoma (MM) and/or dysplastic nevi (DN). However, the biological significance is still uncertain and the persons predisposed to this lesion have not been adequately described. METHODS: Clinicopathologic data of 258 patients, from 263 biopsies diagnosed with DNIEMD, was obtained. A brief voluntary questionnaire was used to obtain demographic, risk factor and disease history. RESULTS: There is an 82% (n=263) predominance of women with DNIEMDs. For men and women, the distributions of these lesions occur on the lower extremities (71%), the upper extremities (24%) and trunk (5%). Thirty-one percent of the 258 patients responded to the questionnaires. 48% of the 60 respondents had green or blue eyes. 26% of 62 respondents had a history of non-melanoma skin cancer (NMSC). Combined data revealed that 68% of 134 patients had a history of DN. As well, 24% of 89 patients had personal histories of melanoma, while 24% of 72 patients had a family history of melanoma. CONCLUSION: Most of these DNIEMD lesions are found on the lower extremities of women and men, and they have an increased association with MM, DN and NMSC.

Incontinentia pigmenti: treatment of IP with topical tacrolimus.

Incontinentia pigmenti (IP), or Bloch-Sulzberger syndrome, is a rare X-linked dominant genodermatosis primarily affecting females. Although IP affects many organ systems, the hallmark feature of this disease is its characteristic cutaneous eruption along the lines of Blaschko that evolves through four distinct stages: inflammatory/vesiculobullous, verrucous, hyperpigmented and hypopigmented/ atrophic. We describe a case of IP in its vesicular stage that completely resolved with topical Protopic (tacrolimus) 0.1% ointment. The treatment successfully halted the progression of disease through its subsequent disfiguring stages.