Herpes zoster granulomatous dermatitis: histopathologic findings in a case series.

Several types of cutaneous reactions have been reported to arise at the site of herpes zoster (HZ) infection weeks to years after the acute disease. Among these, granulomatous reactions are the most frequently reported. In this study, we describe the spectrum of histopathologic findings of HZ granulomatous reactions observed in 26 patients with cutaneous lesions confined to the area of previous HZ eruption and compare them with biopsy specimens taken from 25 patients with acute HZ. All patients with persistent reactions from whom history was available presented within 12 weeks of the onset of the acute eruption. The most frequent findings were interstitial granulomatous dermatitis with lymphocytes, histiocytes and multinucleated giant cells displaying elastophagocytosis and a perineural, perivascular and perieccrine mononuclear inflammatory infiltrate rich in lymphocytes and plasma cells. Less common features included intra-arrector and peri-arrector pili granulomas, follicular dilatation and hyperkeratosis, and vasculitis. Specimens from patients with acute HZ were found to have small numbers of perineural plasma cells and most had subtle granulomatous inflammation, in patterns similar to the group with late granulomatous reactions. Our findings suggest that granulomatous reactions to varicella zoster virus represent a persistent evolving inflammatory reaction after acute infection.

Cutaneous collagenous vasculopathy: a rare cutaneous microangiopathy.

Cutaneous collagenous vasculopathy is a rare microangiopathy of superficial dermal blood vessels. Patients present with telangiectatic macules, predominantly on the extremities. A skin biopsy specimen is necessary to distinguish cutaneous collagenous vasculopathy from generalized essential telangiectasia. Microscopically, cutaneous collagenous vasculopathy resembles the superficial telangiectasias of generalized essential telangiectasia but additionally shows hyaline material in thickened vessel walls. The amorphous pink material is periodic acid-Schiff-positive and resistant to diastase. We describe a series of four patients with cutaneous collagenous vasculopathy and highlight its clinical and histopathologic features.

Cutaneous epithelioid angiomatous nodule: a case with metachronous lesions.

Cutaneous epithelioid angiomatous nodule is regarded as a benign vascular proliferation on the spectrum of epithelioid vascular lesions, probably most closely related to epithelioid hemangioma. Most patients present with solitary lesions. We present an unusual case of an 84-year-old man with multiple epithelioid angiomatous nodules that developed over a 1-year period. Given the multiple lesions, an extensive evaluation for a possible infectious etiology was undertaken. However, no evidence of an infectious agent was identified. The histopathologic differential diagnosis for epithelioid vascular lesions is reviewed.

The inadequacy of punch-excised melanocytic lesions: sampling through the block for the determination of "margins".

BACKGROUND: Dermatopathologists often are asked by clinicians to report margins on punch excisions of melanocytic lesions. OBJECTIVE: We sought to determine the adequacy of surgical margins on melanocytic lesions submitted with intention of complete excision using punch removal technique. METHODS: We conducted prospective analysis of surgical margins on 266 consecutive patients who underwent attempted complete removal of 405 melanocytic nevi submitted as punch and fusiform excisions. RESULTS: Of 206 nonbisected punch excisions, 127 (62%) had final positive margins. Of 159 bisected punch excisions, 76 (48%) had final positive margins. Of 40 elliptical excisions, two (5%) had final positive margins. LIMITATIONS: Information on the perilesional rim of nonpigmented skin included in the excision was not available. CONCLUSIONS: Of punch excisions, 56% had positive margins. Importantly, 30% of these punch excised specimens were negative on initial levels but had positive margins after extensive sectioning, affirming that fusiform excisions are the preferred method to evaluate margins in melanocytic lesions.

Pseudocarcinomatous hyperplasia with follicular differentiation overlying basal cell carcinoma.

We present a series of 25 cases of basal cell carcinoma (BCC) with overlying cytologically bland epidermal hyperplasia and cyst formation. Eight of the BCCs were nodular and 11 were infiltrative. Immunohistochemical staining for Ki-67 and cytokeratin 17 (CK17) was performed to evaluate the proliferative and differentiation characteristics of the hyperplastic epithelium compared with the adjacent BCC and normal epidermis. Fourteen of the 25 cases had sufficient tissue to evaluate the staining patterns. In the majority of cases, Ki-67 expression was prominent throughout the BCCs, but only expressed in the basal and suprabasal layers of the adjacent hyperplastic epithelium, which was equivalent to normal epidermis. CK17 expression was prominent throughout the BCC and surrounding incident hair follicles. CK17 was expressed to a lesser extent in the central more keratinized portions of the hyperplastic epithelium, but rarely in normal epidermis. The morphologic characteristics and immunohistochemical staining patterns in these tumors suggest that the epidermal hyperplasia represents pseudocarcinomatous hyperplasia with follicular differentiation. Recognizing this pattern of epidermal change should alert the pathologist to the possibility of an associated BCC in cases in which the biopsy specimen or sectioning is initially too superficial to reveal the underlying malignancy.

Lipidized dermatofibromas and their relationship to serum lipids.

BACKGROUND: Lipidized dermatofibromas represent a rare variant of dermatofibroma that has been regarded as an incidental finding with no particular clinical significance. OBJECTIVE: The goal of this study was to investigate the relationship between lipidized dermatofibromas and patient age, anatomic location, and serum total cholesterol. METHODS: A retrospective case control format was used with an experimental group containing patients with biopsy-proven lipidized dermatofibromas and a control group containing patients with nonlipidized dermatofibromas. RESULTS: Ages in the experimental group ranged from 35 to 75 years with a mean value of 53 years whereas ages in the control group ranged from 27 to 72 years with a mean value of 48 years. A comparison between the mean of the ages between the two groups using the t test method showed no statistically significant difference (P = .09). Lesion location on the body was grouped into 4 sites: leg, thigh, trunk, and upper extremity. Of the 23 patients in the experimental group, 10 had lesions on the legs, 5 had lesions on the thighs, 2 had lesions on the trunk, and 5 had lesions on the upper extremities. Of the 41 patients in the control group, 15 had lesions on the legs, 7 had lesions on the thighs, 9 had lesions on the trunk, and 10 had lesions on the upper extremities. A comparison between the two groups showed no statistically significant difference (P = .60). In all, 16 of the 23 patients in the experimental group and 24 of the 41 patients in the control group were considered to have high cholesterol. A comparison showed no statistically significant difference between the cholesterol levels of the two groups (P = .38). LIMITATIONS: Limitations that we encountered during the study included the relative infrequency of lipidized dermatofibromas, limiting the number of patients in the study. In addition, medication histories and lipid levels on patients were not always available. In addition, we formed a control group from people who had their cholesterol checked often, which may cause them to have a higher average cholesterol than that of the general population. CONCLUSIONS: Our data show that lipidized dermatofibromas do not differ clinically from nonlipidized dermatofibromas in age distribution of patients, tumor location, or underlying serum lipid levels.

Oncocytic metaplasia occurring in melanoma.

BACKGROUND: Oncocytosis is a cellular feature characterized by the presence of a finely granular eosinophilic cytoplasm due to the accumulation of mitochondria. While this histologic trait can be found in normal tissues, it is also seen pathologically as a degenerative phenomenon. We recently reviewed a spectrum of oncocytic melanocytic nevi that did not have clinical significance. We now describe similar changes in melanoma. METHODS: We retrospectively reviewed 12 melanomas noted to have prominent granular eosinophilic cytoplasm and completed ultrastructural studies. We obtained patient histories and clinical follow-up information from the patients' physicians. RESULTS: All cases were primary melanomas and showed prominent oncocytosis in the majority of the lesional melanoma cells. Oncocytosis was observed in both melanoma in situ and invasive melanoma with a wide range of Breslow thicknesses (range, 0.45-5.05 mm). It occurred in the presence and absence of ulceration, regression, vascular invasion, and brisk tumor infiltrating lymphocytes. Ultrastructural studies revealed melanocytes with numerous distorted mitochondria. CONCLUSION: Melanoma is capable of presenting in a variety of histologic guises, including oncocytic change. While our observations are preliminary, this pathologic curiosity likely represents a degenerative phenomenon of little prognostic importance.

Invasive Trichophyton rubrum infection occurring with infliximab and long-term prednisone treatment.

BACKGROUND: A 64-year-old woman presented with erythematous plaques, tender nodules, and pustules of the dorsal right hand and both legs following long-term treatment with systemic steroids and infliximab. Skin biopsy demonstrated dermal inflammation with foci of necrosis and multinucleated giant cells containing fungal spores. Tissue culture grew Trichophyton rubrum. OBJECTIVE: To report a case that demonstrates the pathophysiology of invasive T. rubrum infection, the mechanisms of action and uses of tumor necrosis factor alpha (TNF-alpha)-inhibiting drugs, and how these drugs may increase patients' risk of invasive dermatophytosis. CONCLUSION: Dermatophytes such as T. rubrum rarely cause invasive disease. This unusual presentation of invasive T. rubrum occurred with immunosuppression by infliximab and systemic steroids. Patients should have a thorough examination for signs of latent infection before TNF-alpha inhibitors are prescribed, including inspection of the skin and nails for signs of dermatophytosis.