Lichenoid Dermatitis in an Adult with Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-Linked (IPEX) Syndrome.

A 23-year-old man presented to our practice with erythroderma and an unusual retiform eruption, along with alopecia universalis and nail dystrophy. He had had no skin findings at birth, but since early infancy had had localized eczematous eruptions of his skin. At 10 years of age, he had developed a generalized eczematous flare requiring hospitalization, and another generalized episode occurred in October 2010. He was prescribed prednisone 60 mg daily, which initially provided an improvement, but tapering of the corticosteroid resulted in another generalized flare.

Dermal Mucinosis in Chronic Sclerodermoid Graft-Versus-Host Disease.

Dermal mucinosis is characterized by the deposition of glycosaminoglycans (mucin), either focally or diffusely within the dermis. This may occur as a primary idiopathic disorder or secondary to several dermatoses, most notably lupus erythematous, scleroderma, and dermatomyositis. The authors present an unusual finding of dermal mucinosis in association with chronic sclerodermoid graft-versus-host disease.

Perforating lichen nitidus.

Transepidermal elimination and/or perforation of the epidermis is seen in a variety of conditions but has only rarely been reported in association with lichen nitidus. We describe a case of lichen nitidus with the unique finding of epidermal perforation, a feature that made the usual straightforward diagnosis of lichen nitidus much more difficult.

A rare case of melanoma with Touton-like giant cells: a potential diagnostic pitfall.

Although approximately 876,000 individuals in the United States currently have a diagnosis of melanoma, the Touton-like giant cell variant has been described only twice in the literature to date. In our case, a 70-year-old man with a history of sclerosing carcinoma on the scalp presented for evaluation of a new nodularity at the site of his previous surgery. On examination, a new complex pigmented lesion on the posterolateral scalp, adjacent to the recurrent sclerosing carcinoma, was noted. Biopsy of the pigmented lesion revealed an invasive melanoma with a Breslow depth of at least 2.78 mm. Microscopic sections showed a predominantly dermal-based tumor composed of sheets and nests of enlarged epithelioid cells. These cells contained oval-to-reniform nuclei with prominent nucleoli and an abundant amount of eosinophilic to vacuolated cytoplasm. Interestingly, numerous multinucleated melanocytes, some with a "Touton" appearance, were scattered throughout the lesion. The lesional cells demonstrated positivity to Mart-1 and HMB-45. Fortunately, the patient's sentinel lymph node biopsy was negative for micrometastases, and a subsequent Position Emission Tomography (PET) scan was unremarkable. Documentation of individual cases of this rare histologic variant of melanoma is necessary given the ability of this lesion to mimic benign histiocytic proliferations at scanning magnification.

Atypical fibrous histiocytoma arising in the perianal area: a case report and review of the literature.

Atypical fibrous histiocytoma (AFH) is an uncommon variant of cutaneous fibrous histiocytoma that can display histologic features associated with malignancy. Fewer than 150 cases have been reported in the literature. The majority of these lesions present on the trunk and extremities of middle-aged women. Genital lesions are rare, with one documented case of vulvar AFH and another case of scrotal AFH in the literature. We report an additional case of a 68-year-old woman who was diagnosed with an AFH in an unusual location, the perianal area. Histologically, the lesion was characterized by a nodular fairly well-circumscribed proliferation of large epithelioid macrophages with scattered lymphocytes and mast cells in the background. The atypical macrophages contained enlarged markedly pleomorphic nuclei with prominent nucleoli. Scattered multinucleated "monster cells" and atypical mitoses were observed throughout the lesion. Immunologically, the lesional cells were focally positive when stained with antibodies against CD163 and Factor XIIIa. They were negative for CD34, CD31, desmin, smooth muscle actin, CAM 5.2, keratin 5/6, S100, CD3, CD20, and CD30. The constellation of histologic and immunologic features was most consistent with an AFH. To our knowledge, this case is the first perianal presentation of AFH to date.

An unusual presentation and distribution of generalized eruptive syringomas.

A 19-year-old Caucasian man presented with numerous erythematous to flesh-colored papules that appeared in crops on his neck, axillae, buttocks, and lower back. The lesions started on his anterior neck at age 12. At 18 years, new crops of papules appeared on his axillae, back, and buttocks over several months. He reported pruritus in the lesions following exercise and perspiration. He denied any family history of similar lesions. His primary care physician treated him with topical triamcinolone 0.1% cream, which made the lesions smaller, less erythematous, and less pruritic; however, the papules never fully resolved. After discontinuation of the steroids, these erythematous pruritic papules gradually recurred in the same areas of his body. The patient denied any other medical complaints.

Reticulin and NM23 staining in the interpretation of lymph nodal nevus rests.

Melanocytic nevus rests in lymph nodes are a known diagnostic challenge, especially in patients with a history of melanoma. Reticulin and NM23 have been studied in this context. The pattern of reticulin staining in melanomas surrounds groups/nests of melanocytes but individual cells in benign nevi. NM23, a metastasis-suppressor gene, has an association with metastatic potential in melanomas and some carcinomas. Twenty-eight cases (14 cases of metastatic melanoma to lymph nodes and 14 cases of lymph node nevus rests, all confirmed with Melan-A staining) were stained with reticulin and NM23. The pattern of reticulin staining was reported as surrounding groups if staining was noted in approximately 5-10 melanocytes in greater than 50% of the lesion but was otherwise reported as surrounding individual melanocytes. Cytoplasmic staining was considered to represent reactivity for NM23. Reticulin staining around groups of melanocytes was identified in all 14 cases of metastatic melanoma. Regarding nodal nevus rest cases, 12 of 14 cases (86%) demonstrated staining around individual melanocytes, whereas in 2 cases, reticulin surrounded melanocytic groups. NM23 staining was equivocal in all cases. Reticulin staining reliably invests groups of melanocytes in cases of metastatic melanoma, whereas in nodal nevus rests, it predominantly surrounds individual melanocytes. NM23 demonstrated no discriminatory value in this analysis. In cases in which a collection of melanocytes is present within a lymph node, reticulin deposition around individual melanocytes supports a diagnosis of lymph nodal nevus rest.

Cutaneous carcinosarcoma with myoepithelial differentiation: immunohistochemical and cytogenetic analysis of a case presenting in an unusual location.

Primary cutaneous carcinosarcoma is an uncommon tumor that is characterized by an admixture of malignant epithelial and mesenchymal elements. To our knowledge, only approximately forty cases have been reported to date in the literature. The majority of these neoplasms occurred on the extremities and the head and neck region of older individuals. We report an additional case, which presented in an 87-year-old man in an unusual location, the buttock. Histologically, the lesion was characterized by a biphasic proliferation of malignant epithelial areas admixed with an infiltrative, poorly differentiated spindle cell component. The epithelial areas consisted of nodular aggregates of basaloid to squamoid cells forming focal ductal structures with central lumens containing proteinaceous debris. The sarcomatoid component consisted of malignant spindle to epithelioid-appearing cells admixed with bizarre-appearing tumor giant cells within a myxochondroid stroma. The epithelial cells showed positive staining with pan-cytokeratin, BerEP4, p63, and keratin 5/6 and were focally positive for S-100, calponin, and actin, consistent with myoepithelial differentiation. An epithelial membrane antigen stain highlighted the scattered ductal structures. The high-grade spindle cell areas were negative for S-100, actin, desmin, calponin, p63, epithelial membrane antigen, and keratin 5/6.

Enteroendocrine cell dysgenesis and malabsorption, a histopathologic and immunohistochemical characterization.

Enteroendocrine cell dysgenesis was observed in 3 patients with intestinal failure of unknown cause. Enteroendocrine cell dysgenesis is a congenitally acquired life-threatening malabsorptive condition with a unique clinical phenotype paired with a histologically identifiable disease pattern. Two cases were first presented at the Ninth International Small Bowel Transplantation Symposium, Brussels 2005, and were subsequently published (N Engl J Med 2006;355:270). We now present the histopathologic and immunohistochemical findings of the gastric antrum, small bowel, and colon in greater detail. The clinical phenotype of the patients was unusual in that the affected patients demonstrated profound malabsorption of all nutrients, except water, from birth. The small intestine in each patient demonstrated almost no abnormality, except a near absence of endocrine cells in the mucosa. The colon appeared similarly affected. Known causes of congenital malabsorption, inflammatory, and infectious causes of diarrhea were excluded. The defect is secondary to point mutations in NEUROG3, which result in an arrest of endocrine cell development in the small intestine and colon. This work describes the pathologic characterization of enteroendocrine cell dysgenesis using routine techniques. The pattern of injury is distinct from other histopathologically assessed congenital malabsorptive conditions such as microvillus inclusion disease, tufting enteropathy, and abetalipoproteinemia. It is also easily distinguished from inflammatory conditions such as food allergy, gluten-sensitive enteropathy, autoimmune enteropathy, IPEX (immune dysfunction, polyendocrinopathy, enteropathy, and X-linked inheritance), and inflammatory bowel disease. The histopathology of disease is similar to what has been found transiently in a single patient with autoimmune polyglandular syndrome type I.