Benign keratosis with a spectrum of follicular differentiation: a case series and investigation of a potential role of human papilloma virus.

BACKGROUND: A variety of dermatopathologic entities are histologically defined by the presence of follicular differentiation. Follicular differentiation confined to the epidermis may follow induction from dermal mesenchymal proliferations, as in a nevus sebaceus of Jadassohn, or represent endogenous proliferations such as the tumor of the follicular infundibulum or trichilemmoma. METHODS: We report on five cases of a histologically distinct form of benign keratosis showing variable follicular differentiation. Clinicopathologic correlation and analysis of a potential human papilloma virus pathogenesis was investigated. RESULTS: Each of the cases arose on the trunk or extremities of three men and two women with a mean age at presentation of 66.6 years. All of the lesions showed variable follicular differentiation, with germinative basaloid cells, matrical cells with matrical keratinization, inner root sheath with trichohyalin granules, or glycogenated lower outer root sheath. Immunohistochemical staining for human papilloma virus was negative in each case. CONCLUSIONS: There exists a distinct entity, histologically defined as a keratosis with variable follicular differentiation, which has not been previously described. These lesions do not appear to be pathogenically related to human papilloma virus infection.

Necrolytic acral erythema associated with hepatitis C: effective treatment with interferon alfa and zinc.

BACKGROUND: Necrolytic acral erythema is a recently described necrolytic erythema that is unique in its exclusive acral location and strong association with hepatitis C. OBSERVATION: We report the first case of necrolytic acral erythema in the United States. The patient is a 43-year-old black woman who presented with a 4-year history of tender, flaccid blisters localized to the dorsal aspect of her feet. Serum zinc and glucagon levels were normal. Serum antibodies were positive for hepatitis C, and a liver biopsy specimen showed chronic hepatitis. She was successfully treated with interferon alfa-2b and zinc. We review all previously reported cases. CONCLUSIONS: Necrolytic acral erythema is a distinct entity. In a review of the literature, most patients were between 35 and 55 years of age, although 1 patient was 12 years old. Five of 8 patients were female. Four of 7 patients described previously were treated with variable success using oral zinc sulfate and amino acids, whereas 2 were successfully treated with interferon alfa. All patients were infected with hepatitis C. Necrolytic acral erythema appears to be a skin disorder linked to infection with hepatitis C virus that responds to treatment with interferon alfa and oral zinc.

Ocular adnexal oncocytoma: a case series and clinicopathologic review of the literature.

The authors report the clinical, microscopic, and ultrastructural features of four oncocytic lesions involving the ocular adnexa. Three of the lesions originated in the ocular caruncle of elderly women, and a single case was encountered from the medial eyelid of an elderly man. Each lesion clinically presented as a slow-growing, painless, red mass. The histopathologic features were distinctive, with polyhedral cells containing granular eosinophilic cytoplasm found to consist of large numbers of mitochondria on ultrastructural examination. Of the 40 cases previously reported primarily in the ophthalmologic literature, the cases reported here similarly involved the eyelid and associated ocular adnexa with a predilection for elderly women. Oncocytomas probably represent an age-associated metaplastic and neoplastic transformation of the glandular epithelium comprising the ducts of salivary glands.

Fibronectin and the extracellular matrix in the perforating disorders of the skin.

Despite detailed microscopic descriptions and clinical observation, little is known regarding the pathogenesis of the perforating disorders of skin, which have traditionally been subdivided into numerous microscopic entities associated with various clinical settings. An increasing body of evidence now suggests that the perforating disorders of skin are akin, and may constitute an expanded single pathologic entity. Each of the classic perforating disorders of skin, including elastosis perforans serpiginosa, perforating folliculitis, reactive perforating collagenosis, Kyrle's disease, and perforating disorder of uremia, have been shown to extrude collagen, elastin, and related extracellular matrix components through the epidermis. Considering a shared pathogenic mechanism among these entities, we explored the possible role of the extracellular matrix, in particular fibronectin, in perforating disorders of skin. Using immunohistochemical and serum determinations of extracellular matrix constituents, including fibronectin, collagen type IV, laminin, and tenascin, we showed consistent serum elevation and/or deposition of fibronectin, in each case, without a commensurate increase in laminin, collagen type IV, and tenascin. We propose that elevated serum and tissue concentrations of fibronectin may be responsible for inciting, in a physiologically aberrant manner, increased epithelial migration and proliferation culminating in perforation.

Pigmented lesions in actinically damaged skin. Histopathologic comparison of biopsy and excisional specimens.

BACKGROUND AND DESIGN: A consecutive sample of 46 cases was collected for comparative histologic evaluation. Results of incisional biopsies of cutaneous pigmented lesions interpreted as lentigo maligna, melanoma in situ, or invasive melanoma, and those suggestive, but not diagnostic, of melanoma were collected. Those lesions that were on actinically damaged skin and in which biopsy was followed by complete excision within 6 months were included. Incisional biopsies that removed greater than 50% of the surface area of the lesion were excluded. RESULTS: Of the excisional specimens, 40% demonstrated histopathologic features more pronounced than those in the biopsy specimens. Areas of invasive melanoma not detected in the biopsy specimens were observed in 20% of the excisional specimens. Accurate diagnosis based on small biopsy specimens was not always possible because of the absence of a classic lentigo maligna histologic pattern in many cases. The most frequent deviation from the pattern was the presence of lentiginous epidermal hyperplasia within these lesions. CONCLUSIONS: These results suggest that limited sampling may be inadequate for an accurate diagnosis of pigmented melanocytic lesions on actinically damaged skin. Areas chosen for biopsy may not contain the most advanced areas histologically and may fail to detect foci of invasive melanoma elsewhere within the lesion.

Fatal cutaneous necrosis mimicking calciphylaxis in a patient with type 1 primary hyperoxaluria.

BACKGROUND: Cutaneous necrosis of the proximal lower extremities in a patient with end-stage renal disease is the classic presentation of calciphylaxis, an untreatable, rare, generally fatal necrotizing cutaneous syndrome. Type 1 primary hyperoxaluria (PH-1) usually presents in childhood with recurrent urolithiasis. Since enzymatic studies to confirm the metabolic defect are now available, some cases of idiopathic renal failure in adulthood have been shown to be caused by PH-1. These patients may develop vascular oxalate deposits resulting in livedo reticularis and distal acral vascular insufficiency. OBSERVATIONS: We describe a patient who presented in end-stage renal failure with proximal lower extremity cutaneous necrosis suggestive of calciphylaxis. A cutaneous biopsy specimen revealed oxalate crystals within blood vessels, and a diagnosis of PH-1 was confirmed enzymatically. CONCLUSIONS: This patient illustrates that PH-1 may present in adulthood, and, in the setting of cutaneous necrosis associated with end-stage renal disease, it may be confused with calciphylaxis. The importance of making a diagnosis of PH-1 is the potential ability to achieve long-term survival by reversing the underlying metabolic defect with hepatic transplantation.

Pretibial mucin. Histologic patterns and clinical correlation.

BACKGROUND AND OBJECTIVE: We identified several patients with a histologic diagnosis of pretibial myxedema in whom thyroid disease was not found. The purpose of this study was to investigate if histologic characteristics can distinguish between pretibial mucinosis secondary to Graves' disease and that unassociated with thyroid disease. METHODS: Biopsy specimens interpreted as compatible with pretibial myxedema were reviewed; these included 12 cases of pretibial mucinosis with documented Graves' disease, and six cases of pretibial mucinosis without evidence of Graves' disease. Ten specimens interpreted as compatible with stasis dermatitis were also evaluated for histologic characteristics, including the possible presence of mucin. RESULTS: Features that distinguish between pretibial mucinosis associated with Graves' disease and pretibial mucinosis without Graves' disease included preservation of a zone of normal-appearing collagen in the superficial papillary dermis (12/12 with Graves' disease, 0/6 without), mucin deposition in the reticular dermis (12/12 with Graves' disease, 0/6 without), lack of mucin deposition in the superficial papillary dermis (11/12 with Graves' disease, 1/6 without), angioplasia (2/12 with Graves' disease, 6/6 without), and the presence of hemosiderin (2/12 with Graves' disease, 6/6 without). Mucin deposition in the papillary dermis was found in six of 10 specimens interpreted as stasis dermatitis. CONCLUSIONS: There are patients with pretibial mucinosis in whom there is no thyroid disease. Specimens from patients without Graves' disease have features of stasis dermatitis in addition to mucinosis. We conclude that pretibial mucinosis may result from stasis or Graves' disease and that histologic differences allow for accurate differentiation.