Contiguous lesions in lentigo maligna

BACKGROUND

Determining the best biopsy technique for a suspected lentigo maligna can be challenging. Because complete excisional biopsy is rarely practical, the physician is left to choose an appropriate area to biopsy. Sampling error can have devastating consequences, especially if the biopsy demonstrates a pigmented lesion that was considered in the clinical differential diagnosis. The presence of a solar lentigo, pigmented actinic keratosis, or reticulated seborrheic keratosis could mislead the pathologist and clinician to the erroneous conclusion that the incisional specimen is representative of the whole, and that no lentigo maligna is present.

OBJECTIVE

We have often observed the presence of a contiguous pigmented lesion adjacent to lentigo maligna. The current study was designed to determine how frequently this phenomenon occurs.

METHODS

We studied Mohs debulking specimens of lentigo maligna, and broad shave biopsy specimens of pigmented lesions on heavily sun-damaged areas of the skin proven to be lentigo maligna.

RESULTS

Contiguous pigmented lesions were present in 48% of the specimens. The most common lesion was a benign solar lentigo (30%), followed by pigmented actinic keratosis (24%).

CONCLUSION

Recognition of this phenomenon may prevent misdiagnosis of lentigo maligna related to sampling error.

Atypical junctional melanocytic proliferations in benign lichenoid keratosis

Melanocytic lesions with lichenoid regression may mimic a benign lichenoid keratosis (BLK) histologically. A total of 336 BLKs were reviewed and deeper sections obtained to determine the frequency of this phenomenon. Two cases (0.6%) showed at least 1 melanocytic nest or junctional multinucleated melanocyte (starburst melanocyte) on deeper sections confirmed by MART-1 immunostaining. Both of these cases demonstrated solar elastosis, and 1 case had an effaced rete ridge pattern. Not included in the histological study are 5 additional cases in which the initial slide showed only lichenoid dermatitis, but deeper sections obtained before to the initial sign-out revealed a melanocytic proliferation. These 5 cases would have been signed out as "consistent with BLK" if deeper sections had not been obtained. Fluorescent in situ hybridization (FISH) was performed on 3 cases; in each case, the melanocytes demonstrated a loss of chromosome 9p21 DNA copy number. The finding of nests of genetically altered melanocytes on severely sun-damaged skin strongly suggests that these cases represent lichenoid regression of melanoma in situ. Pathologists should approach a diagnosis of BLK cautiously in the setting of severely sun-damaged skin.

A case of bullous pemphigoid limited to psoriatic plaques

Psoriasis occurs with increased incidence in patients with bullous pemphigoid (BP). In this article, we describe the seventh reported English literature case in which the bullous lesions were limited to psoriatic plaques, and we discuss the pathophysiologic mechanisms that might explain this phenomenon. Treatment with acitretin quickly cleared both psoriatic and bullous lesions, suggesting a direct link between the psoriatic inflammatory process and the evolution of bullous lesions.

Gloves and socks syndrome: early and late histopathologic features

BACKGROUND

Gloves and socks syndrome (GSS) is a recently described exanthem, most commonly caused by parvovirus B19.

OBJECTIVE

Our purpose was to describe both early and late histopathologic features of GSS.

METHODS

We performed histopathologic examination of biopsy specimens from a case of GSS and reviewed all the English-language literature reports of GSS to compare the reported histologic descriptions.

RESULTS

A total of 46 cases of GSS have been reported in the English-language literature. In 18 of those, the pathologic features were described. The histologic features of the current case evolved from a nonspecific superficial perivascular lymphocytic infiltrate to a vacuolar interface dermatitis with necrotic keratinocytes, erythrocyte extravasation, and a superficial perivascular and interstitial lymphocytic infiltrate.

CONCLUSION

Early lesions of GSS show nonspecific features common to viral exanthems. The late features, of a fully evolved exanthem, demonstrate a vacuolar interface dermatitis with necrotic keratinocytes, a superficial perivascular and interstitial infiltrate, and dermal hemorrhage. These late pathologic features, together with the clinical appearance of GSS, may help distinguish it from other entities.

Infantile digital fibroma treated with mohs micrographic surgery

BACKGROUND

Infantile digital fibroma (IDF) is a rare benign fibrous tumor of childhood that frequently recurs despite local excision. Conservative, nonsurgical management may result in regression and/or joint deformity.

OBJECTIVE

To describe the histologic features of IDF and discuss a case excised using Mohs micrographic surgery (MMS).

METHODS

Case report and review of the clinical, histologic, and ultrastructural features.

RESULTS

Characteristic inclusion bodies of actin were identified with hematoxylin and eosin, Masson's trichrome, and rapid actin immunostain. The tumor was debulked and the majority was removed after one stage of MMS, except where the deep margin approached the joint space. The defect healed by secondary intention. At 2 years the patient had no recurrence or functional joint deformity.

CONCLUSION

MMS is a surgical treatment option for IDF.

Trichosporon beigelii infection presenting as white piedra and onychomycosis in the same patient

Trichosporon beigelii is a fungal organism that causes white piedra and has occasionally been implicated as a nail pathogen. We describe a patient with both hair and nail changes associated with T. beigelii.

Mohs micrographic surgery for melanoma: a case series, a comparative study of immunostains, an informative case report, and a unique mapping technique

BACKGROUND

Mohs micrographic surgery (MMS) has been established as an alternative to standard surgical excision for local cutaneous malignant melanoma (MM) and melanoma in situ (MIS). The use of melanocyte-specific immunohistochemical stains may improve the diagnostic accuracy of MMS frozen sections.

OBJECTIVE

We used MMS with immunostains to determine the maximum and minimum margins required to clear 52 melanomas, mostly MIS of the head and neck. We sought to identify the most sensitive melanocyte immunostain for use in MMS frozen sections and to improve the clinicopathologic correlation of perilesional pigmented lesions.

METHODS

We studied 52 consecutive cases of invasive melanoma (n = 10) and MIS (n = 42), tabulating the maximum and minimum margins required for complete tumor resection in any one direction during MMS. In 10 of these cases we studied the relative sensitivity of the immunostains MART-1, S-100, and HMB-45 in Mohs frozen sections. We describe a case highlighting the importance of the increased sensitivity of MART-1. In 12 patients we used a unique mapping technique to help determine the clinical relevance of a total of 35 perilesional pigmented foci.

RESULTS

The maximum margin averaged 10.1 mm (range 3-26 mm) for MM and 9.4 mm (range 3-18 mm) for MIS. The minimum margin averaged 7.0 mm (range 3-13 mm) for MM and 5.5 mm (range 3-11 mm) for MIS. For individual tumors, the difference between the minimum and maximum margin averaged 3.7 mm (range 0-13 mm). This difference was >or=5 mm in 38% (20/52) and >or=10 mm in 10% (5/52), highlighting that subclinical tumor extension is often broad and asymmetric. While five of six MM less than 1.0 mm in depth would have been cleared with a routine 1 cm excision, a standard 5 mm margin would have cleared less than one-quarter of the cases of MIS (10/42). In Mohs frozen sections, MART-1 proved superior in sensitivity to both HMB-45 and S-100. Our mapping technique provided clinically relevant histologic correlation for perilesional pigmented lesions, improving the Mohs surgeon's ability to evaluate equivocal foci in frozen sections.

CONCLUSION

MM, especially MIS on the head and neck, often exhibits an asymmetric growth pattern, making it quite suitable for treatment with MMS. The use of MART-1 immunostain may improve the diagnostic accuracy of Mohs surgeons. We believe that HMB-45 should not be used to rule out the diagnosis of MIS in equivocal sections because of its inferior sensitivity. We introduce a new mapping technique as an adjunctive measure to aid in the clinicopathologic evaluation of perilesional skin.

Lichenoid tissue reaction in malignant melanoma: a potential diagnostic pitfall

Lichenoid tissue reactions can occur in malignant melanoma and may cause partial regression of the lesion. We studied a series of melanomas to determine how frequently lichenoid tissue reaction obscures the diagnosis of malignant melanoma. We retrospectively reviewed 342 cases of invasive malignant melanoma and melanoma in situ from the head, neck, chest, and back. Of the 342 cases, 23 (6.7%) had a lichenoid tissue reaction obscuring a portion of the lesion. In 6 cases (1.8%), the lichenoid tissue reaction replaced a major portion of the lesion. Knowledge of this phenomenon can prevent misdiagnosis.

Cutaneous Waldenström's macroglobulinemia: report of a case and overview of the spectrum of cutaneous disease

Specific infiltration of the skin is a rare complication of Waldenström's macroglobulinemia. Cutaneous disease may also develop as a direct result of paraproteinemia and paraprotein specific antiepidermal autoimmune disease. We report a patient with Waldenström's macroglobulinemia in whom cutaneous infiltration developed with a clonal population of lymphoplasmacytoid B cells, summarize previously reported cases, and review the spectrum of cutaneous disease associated with this hematologic malignancy.

Arthropathy associated with cystic acne, hidradenitis suppurativa, and perifolliculitis capitis abscedens et suffodiens: treatment with isotretinoin

A patient with arthropathy associated with cystic acne, hidradenitis suppurativa, and perifolliculitis capitis abscedens et suffodiens who showed a dramatic response to isotretinoin is described. This, to our knowledge, is the first report documenting effective treatment of this condition, whose nosologic position with respect to other spondyloarthropathies associated with cutaneous disease is considered.

Dermatofibrosarcoma protuberans in an infant with a history of choroid plexus papilloma

We describe an infant with a dermatofibrosarcoma protuberans (DFSP) who also had a choroid plexus papilloma. This report underscores the occurrence of DFSP in this age group and may support a neural pathogenesis of this tumor.

Treatment of lichen planus and lichen nitidus with itraconazole: reports of six cases

Six patients with either lichen planus or lichen nitidus were treated with itraconazole. Two of four patients with lichen planus experienced complete clearing, and the remainder showed a partial response. Itraconazole, like griseofulvin, may prove to be an alternative treatment worth considering in patients with lichen planus or lichen nitidus who have failed other therapies.

Symmetrical erosions in a neonate: a case of neonatal sucking blisters

Neonatal sucking blisters appears as unilateral or bilaterally symmetrical bullae or erosions involving the distal upper extremities at birth. They represent minor self-inflicted trauma, presumably the result of a vigorous intrauterine sucking reflex. Recognizing this benign self-limited condition avoids unnecessary tests and alleviates anxiety on the part of the infant's family and physicians.

Lichen sclerosus following the lines of Blaschko

A case of lichen sclerosus that developed in a pattern corresponding to the lines of Blaschko is described. This pattern of extragenital lichen sclerosus has not, to our knowledge, previously been reported and could result from an epidermal clone with altered androgen sensitivity supporting a hormonal pathogenesis for this disease.

Cutaneous heparin necrosis in a patient with heterozygous protein S deficiency

A patient with heterozygous protein S deficiency experienced cutaneous necrosis following subcutaneous heparin administration. Deficiencies of both protein C and protein S, known risk factors for the more frequently encountered coumarin necrosis, may predispose patients to this complication of heparin therapy as well. The putative association of protein S deficiency with cutaneous heparin necrosis could not be proven, however, since attempts to reproduce the heparin necrosis were unsuccessful.

Congenital subungual nevus in a black infant

A 6-month-old black infant is described with a congenital black subungual and periungual lesion of the right second toe. Histopathologic examination revealed a junctional nevus. Congenital subungual nevi are rare. To the best of our knowledge, this represents the first report in a black infant.

Phakomatosis pigmentovascularis type IIIb

A patient with a giant nevus flammeus, giant nevus spilus, and Klippel-Trenaunay-Weber syndrome is described. This case can be designated phakomatosis pigmentovascularis type IIIb and may represent the second case thus far reported.

Post-cardiac transplant reactivation of Chagas' disease diagnosed by skin biopsy

Reactivation of Chagas' disease in immuno-compromised hosts may represent a recognizable clinical syndrome that can be diagnosed by examination of skin biopsy specimens of characteristic lesions resembling ordinary bacterial cellulitis. This syndrome appears to result in significant morbidity, which can be avoided with the institution of prophylactic therapy for Chagas' disease. An awareness of this complication of immunosuppression is of paramount importance for the thousands of asymptomatic persons infected with Chagas' disease currently living in the United States and abroad.

Pigmented nail streaks may indicate Laugier-Hunziker syndrome

Laugier-Hunziker syndrome is a rare, benign pigmentation disorder previously described only once in the United States. The syndrome is acquired in early or mid-adult life and is characterized by multiple longitudinal hyperpigmented bands on the nails and pigmented macules of the lips and buccal mucosa. Peutz-Jeghers syndrome and Addison's disease can present with pigment abnormalities similar to those characteristic of Laugier-Hunziker syndrome.

Ultraviolet radiation acts as an independent mitogen for normal human melanocytes in culture

Identification of growth factors for normal human melanocytes has been significantly aided by the recent development of in vitro culture systems for this cell. Utilizing such a system, we studied the effect of ultraviolet radiation (UVR) on both melanocyte growth and melanization by incorporation of 3H-thymidine and 3H-L-dihydroxyphenylalanine (3H-DOPA), respectively. 3H-thymidine incorporation was found to be significantly stimulated during the first 24 h following a single irradiation. 3H-DOPA incorporation was stimulated after a delay of 2 days postirradiation. Whereas UVR has long been known to induce melanocyte proliferation in vivo, these studies show that UVR can act as a mitogenic stimulus for this cell independent of the cutaneous environment. UVR can thus be added to a growing list of growth factors for epidermal pigment cells and is the only physical agent conclusively shown to act as a mitogen. Included in this list are substances that act via stimulation of the CAMP-kinase or protein kinase systems such as cholera toxin and phorbol esters. UVR is postulated to induce melanocyte proliferation by modulation of these second messenger pathways. With recent evidence linking growth factors, oncogenes and malignant transformation, this study supports the association between UVR exposure and the development of malignant melanoma, and suggests mechanisms whereby UVR may contribute to malignant transformation of this cell.