Atypical carcinoid metastasis to the skin.

Carcinoid tumors are derived from neuroendocrine cells, and are most frequently found in the gastrointestinal tract and bronchopulmonary system. Cutaneous involvement of carcinoid tumors is relatively rare, with isolated case reports in the literature. We detail a patient with stage IV pulmonary atypical carcinoid tumor with skin metastasis. This case is unusual because the patient did not have any erythema or induration of the scalp, only a complaint of pain. On biopsy, the tumor cells had cytologic features of a carcinoid tumor, but were arranged as infiltrating cords, small aggregates and single units, rather than the organoid or trabecular pattern seen in the primary tumor. Further, along with neuroendocrine markers, the tumor cells had the staining pattern of cytokeratin 7+/cytokeratin 20-/thyroid transcription factor-1+, supporting a carcinoid tumor of lung origin. Thus, this case of skin metastasis from an atypical pulmonary carcinoid tumor illustrates a unique clinical and histologic presentation.

Massive localized lymphedema: A soft tissue process that may present to dermatologists.

Massive localized lymphedema (MLL) is a clinically and histologically distinct entity seen in morbidly obese patients. We describe two obese patients with MLL in the lower abdomen and suprapubic area. Biopsies showed characteristic histologic features of an expanded dermis with lymphangiectases, fibrotic septae and focal fat necrosis. One patient had long-standing hypothyroidism, an association previously reported. This disease is frequently complicated by recurrent cellulitis and may be amenable to surgery. Patients with MLL may present to dermatologists, and this disease has characteristic histopathologic findings that may mimic liposarcoma to the unaware dermatopathologist.

Facial follicular porokeratosis: a case report.

Porokeratosis is a disorder of keratinization, characterized clinically by a peripheral keratotic ridge and histologically by the cornoid lamella. We describe a patient with follicular porokeratosis with a distinctive clinical presentation. We believe that follicular porokeratosis is a unique histopathologic variant of porokeratosis, with cornoid lamellae centered in follicular infundibula. Further, this is the only report of follicular porokeratosis involving the face exclusively.

Porokeratotic eccrine ostial and dermal duct nevus: a report of 2 cases and review of the literature.

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is a rare disorder of keratinization involving the intraepidermal eccrine duct (acrosyringium). We detail two examples of this unique clinicopathological entity--one with a more typical clinical presentation and one with a solitary lesion and late adult onset. In addition, we discuss the distinctive histologic and immunohistochemical findings and review the literature.

Histopathology and X-ray microanalysis of foreign material on facial keratoses.

Opaque exogenous material was frequently observed on the surface of keratoses during routine sign out by one of us (H.K.). To investigate this material further, 300 consecutive seborrheic keratoses were reviewed: 100 cases from the face of women, 100 cases from the face of men, and 100 cases from the trunk of men and women. All cases were evaluated by light microscopy for the presence and quantity of exogenous material, and 14 cases were studied by x-ray microanalysis to assess its composition. The material was present on 54% of facial keratoses from predominantly older women (mean age 67 years), 5% of facial keratoses from men, and 9% of truncal keratoses from men and women. The x-ray microanalysis showed the presence of a variety of elements, including titanium (13 cases), silicon (12 cases), iron (9 cases), aluminum (8 cases), magnesium (8 cases), zinc (4 cases), barium (2 cases), and bismuth (2 cases). We believe that the exogenous material represents cosmetic products such as colored facial cosmetics, sunscreens, and moisturizers. Further, because the exogenous material was found predominantly on facial keratoses of older women, the presence of this material in a specimen may serve as a clue to the patient's gender, age, and biopsy site.

Bacillary angiomatosis associated with pseudoepitheliomatous hyperplasia.

Bacillary angiomatosis is an opportunistic bacterial infection caused by either Bartonella henselae or B. quintana. The classic histologic presentation of bacillary angiomatosis involves three components: a lobular proliferation of capillaries with enlarged endothelial cells, neutrophilic debris, and clumps of finely granular material identified as bacteria with staining techniques. Pseudoepitheliomatous hyperplasia is a histologic reaction pattern characterized by epithelial proliferation in response to a variety of stimuli, including mycobacterial, fungal, and bacterial infections. We describe a case of bacillary angiomatosis associated with pseudoepitheliomatous hyperplasia in an immunocompromised patient with Acquired Immunodeficiency Syndrome. Histologic examination of a finger lesion demonstrated a capillary proliferation with neutrophilic debris and characteristic amorphous granular deposits. Warthin-Starry and Giemsa staining revealed clumps of coccobacilli. Cervical lymph node tissue also revealed organisms identified as Bartonella with PCR techniques. Stains and cultures for acid fast bacilli, fungus, and bacteria were negative. To our knowledge, there has been only one other report of bacillary angiomatosis presenting with pseudoepitheliomatous hyperplasia. We conclude that the differential diagnosis of entities associated with pseudoepitheliomatous hyperplasia should be expanded to include bacillary angiomatosis.