Janine C. Malone

Three‐dimensional imaging of human skin and mucosa by two‐photon laser scanning microscopy

Background: Various structural components of human skin biopsy specimens are difficult to visualize using conventional histologic approaches.

CD10 Expression in Cutaneous Adnexal Neoplasms and a Potential Role for Differentiating Cutaneous Metastatic Renal Cell Carcinoma

CONTEXT Recent investigations have demonstrated the utility of CD10 as a marker for renal cell carcinoma (RCC). Cutaneous metastases occur in up to 11% of patients with RCC and may be the presenting sign of widespread disease. The differential diagnosis in histopathologic evaluation of these cases includes cutaneous adnexal neoplasms, and describing the expression of CD10 in these tumors may be helpful in delineating the differential diagnosis. OBJECTIVE To determine CD10 expression in a variety of adnexal lesions and to determine the diagnostic utility of CD10 in an immunohistochemical panel differentiating metastatic cutaneous renal cell carcinoma from cutaneous adnexal neoplasms. DESIGN We studied 57 primary adnexal neoplasms of eccrine (n = 31), apocrine (n = 16), and sebaceous (n = 10) differentiation as well as normal skin (n = 3) and RCC metastatic to the skin (n = 4). A CD10 monoclonal antibody was applied to formalin-fixed, paraffin-embedded tissue. Specimens were randomized and categorized as immunopositive or immunonegative by a pathologist with expertise in immunohistochemistry who was blinded to the diagnoses. RESULTS Two (6.5%) of 31 eccrine, 1 (6%) of 16 apocrine, and 4 (40%) of 10 sebaceous neoplasms demonstrated CD10 immunopositivity. Four (100%) of 4 RCC were CD10 immunopositive. CD10 expression was significant for eccrine and apocrine neoplasms (P < .001) compared to metastatic RCC, but not for sebaceous neoplasms (P = .08). CONCLUSION Based on these results, CD10 is a useful additional immunostain for the discrimination of RCC metastatic to the skin and cutaneous adnexal neoplasms with eccrine and apocrine differentiation, but not with sebaceous differentiation.

Cutaneous malignant peripheral nerve sheath tumors

Cutaneous malignant peripheral nerve sheath tumors (MPNSTs) are rare entities compared with their deep soft tissue counterparts. We describe two cases of cutaneous MPNSTs. The first case, occurring in a 27‐year‐old woman with neurofibromatosis I, presented with recent growth of a pre‐existing nodule on her back. A biopsy showed a densely cellular area within a conventional neurofibroma composed of atypical, hyperchromatic epithelioid and spindled cells with frequent mitotic figures (MFs). The second case presented in an 88‐year‐old man with no stigmata of neurofibromatosis as a rapidly growing subcutaneous tumor of the right calf. A biopsy showed a diffuse neurofibroma that abruptly transitioned to a densely cellular proliferation of hyperchromatic atypical spindled cells arranged in short fascicles with frequent MFs. The diagnosis of MPNST was rendered in both cases. MPNSTs of the dermis and subcutis are rare sarcomas. They can occur as sporadic tumors or in the setting of neurofibromatosis. They are often associated with pre‐existing neurofibromas. Increase in size of pre‐existing neurofibromas is an indication for biopsy. Recognition of the cellular atypia, increased cellularity and mitotic activity is key to the diagnosis.

Generalized eruptive histiocytosis

The histiocytic disorders can be broadly categorized into histiocytosis X (Langerhans cell-derived) and non-X types. There are several variants of non-X histiocytoses that tend to occur in a generalized distribution on the body; these include xanthoma disseminatum, generalized eruptive histiocytosis (GEH), progressive nodular histiocytosis, and multicentric reticulohistiocytosis. Clinical and pathologic correlation are required for differentiating among these 4 disorders. We report a case of a middle-aged man in whom small, scattered, symmetrical lesions on the trunk and proximal extremities developed that, after correlating with biopsy specimen and laboratory results, were best classified as a non-X histiocytosis with features of GEH. GEH is a rare generalized non-X histiocytosis that occurs mainly in adults. It is characterized by multiple, scattered, symmetric lesions on the trunk and proximal extremities that are benign in nature and tend to resolve spontaneously. Recent literature has suggested that GEH may be a part of a continuous spectrum of non-X histiocytic disorders.

Atypical Fibroxanthoma With Regional Lymph Node Metastasis: Report of a Case and Review of the Literature

BACKGROUND Atypical fibroxanthoma (AFX) is a low-grade sarcoma usually occurring on sun-damaged skin of the head and neck in elderly patients. Metastatic disease has been reported very rarely. The potential aggressiveness of AFX is controversial. OBSERVATIONS We describe herein a patient who developed metastatic disease in cervical lymph nodes. Our patient was an 87-year-old man with a 7-week history of a rapidly growing AFX presenting as a 1.5-cm sessile nodule on his right mandible. Two months following excision, the patient developed cervical lymphadenopathy. Histopathologic analysis of the cervical lymph nodes revealed spindle-cell tumors with histologic characteristics identical to those of the primary AFX, and the tumors were immunonegative for cytokeratin MNF-116 and S-100. In addition, we review and analyze cases from the literature and articles related to immunohistochemical stains used to diagnose AFX. CONCLUSIONS Atypical fibroxanthoma is a diagnosis of exclusion, and only a small number of metastatic AFX cases have been reported. A review of the literature pertaining to immunohistochemical stains suggests the potential benefit of use of CD10, procollagen I, CD99, CD117, p63, and LN-2 in differentiating AFX from other spindle-cell tumors. The metastatic potential of AFX may not be fully appreciated, and clinicians should be reminded of its potential aggressive behavior.

Clonal relationships between epidermotropic metastatic melanomas and their primary lesions: a loss of heterozygosity and X-chromosome inactivation-based analysis.

Loss of heterozygosity (LOH) has previously been demonstrated at multiple chromosome microsatellites in primary and metastatic melanomas. Epidermotropic metastases of melanoma are unique in their varied histopathologic appearance, which can mimic a primary lesion. Our objective was to compare LOH profiles in primary and epidermotropic metastatic melanoma to delineate their clonal relationship. We examined the pattern of allelic loss in the primary melanomas of nine patients in addition to the 21 corresponding epidermotropic metastatic melanomas (average 2.3 metastases per patient). DNA samples were prepared from formalin-fixed, paraffin-embedded tissue sections using laser capture microdissection. Eight DNA microsatellite markers on six different chromosomes were analyzed: D1S214 (1p), D6S305 (6q), D9S171 (9p), D9S157 (9p), IFNA (9p), D10S212 (10q), D11S258 (11q), D18S70 (18q). In addition, X-chromosome inactivation analysis was performed in tumors from four women. LOH was seen in 67% (6/9) of primary melanomas and 81% (17/21) of epidermotropic metastatic melanomas. The most frequent allelic losses in informative cases occurred at 10q (33%), 9p (22%), and 11q (22%) in primary melanomas, and at 10q (50%), 1p (44%), and 6q (39%) in epidermotropic metastatic melanomas. Primary lesions demonstrating LOH had concordant allelic loss in at least one locus in a corresponding epidermotropic metastatic melanoma in 83% (5/6) of cases. X-chromosome analysis showed nonrandom inactivation in 75% (3/4) and 71% (5/7) of primary melanoma and epidermotropic metastatic melanoma cases, respectively. Our LOH and X-chromosome inactivation analysis data suggest that epidermotropically metastatic melanomas are clonally related to their primary lesion in many cases. Our data also indicated that some cases diagnosed as epidermotropic metastatic melanoma might be divergent clones or new primaries rather than metastatic disease.

Oxalosis Involving the Skin: Case Report and Literature Review

BACKGROUND The primary hyperoxalurias are a group of rare autosomal recessive metabolic disorders associated with abnormal overproduction of serum oxalate and subsequent deposition in tissue. Most patients present at an early age with recurrent urolithiasis and renal failure. Vascular deposition of oxalate-producing skin manifestations, such as livedo reticularis, acrocyanosis, peripheral gangrene, and ulcerations, is typical of the primary hyperoxalurias. OBSERVATIONS We present the case of a 38-year-old woman with end-stage renal disease receiving hemodialysis with progressive skin changes, including livedo reticularis, superficial eschars, and brawny, woody fibrosis of her extremities, who was clinically suspected to have calciphylaxis or nephrogenic systemic fibrosis. Cutaneous biopsy specimens revealed rectangular, birefringent, yellowish-brown, polarizable crystalline material suggestive of oxalate within the dermis, subcutis, and medium-size vessels along with areas of focal epidermal and superficial dermal necrosis. Her subsequent medical history was obtained and was suggestive of a diagnosis of primary hyperoxaluria. CONCLUSIONS This case highlights the variability of clinical presentations in primary hyperoxaluria and that the disease can be diagnosed in adulthood. In addition, this case demonstrates that hyperoxaluria should be included in the differential diagnosis of calciphylaxis and nephrogenic systemic fibrosis.

Hydroxyurea-Associated Dermatomyositis-like Eruption Demonstrating Abnormal Epidermal p53 Expression: A Potential Premalignant Manifestation of Chronic Hydroxyurea and UV Radiation Exposure

BACKGROUND Chronic hydroxyurea therapy is associated with numerous cutaneous adverse effects. While hydroxyurea-associated nonmelanoma skin cancers are known to be associated with significant morbidity and occasional mortality, to date, dermatomyositis-like eruption has been considered a benign entity, other than its ability to mimic true dermatomyositis leading to inappropriate immunosuppression. More recently, hydroxyurea-associated squamous dysplasia has been characterized as a premalignant precursor to hydroxyurea-associated nonmelanoma skin cancers and shown to manifest abnormal p53 expression. OBSERVATIONS An elderly woman receiving chronic hydroxyurea therapy for myelodysplasia developed a dermatomyositis-like eruption that was misdiagnosed as true dermatomyositis, leading to continuation of hydroxyurea. Years later she developed severe hydroxyurea-associated nonmelanoma skin cancers resulting in discontinuation of hydroxyurea, poor control of her myelodysplasia, and death. Re-evaluation with immunohistochemical analysis of tissue from her original dermatomyositis-like eruption revealed focal confluent nuclear expression of p53 along the lower layers of the epidermis, suggestive of a premalignant state. CONCLUSIONS We suggest that dermatomyositis-like eruption and hydroxyurea-associated squamous dysplasia represent similar clinical manifestations of a common underlying chronic phototoxic process involving aberrant keratinocyte p53 expression mediated by hydroxyureas antimetabolite properties and UV radiation exposure. Accordingly, we suggest that dermatomyositis-like eruption, previously considered a benign entity, may represent a premalignant precursor of hydroxyurea-associated nonmelanoma skin cancers warranting discontinuation of hydroxyurea therapy.

Sweet-like Dermatosis in 2 Patients With Clinical Features of Dermatomyositis and Underlying Autoimmune Disease

BACKGROUND The neutrophilic dermatoses comprise a group of cutaneous disorders that are characterized histopathologically by infiltration of the dermis with mature neutrophils with or without vessel wall destruction. Neutrophilic dermatoses have been reported in association with a variety of autoimmune diseases, most recently as a manifestation of lupus erythematosus. OBSERVATIONS We describe 2 patients with photodistributed violaceous plaques: one with associated heliotrope rash and malar erythema, and the other with scalp involvement and Gottron-like papules. In each case, the biopsy specimen revealed changes compatible with a neutrophilic dermatosis as opposed to an interface dermatitis. The first patient also had a history of Graves disease and primary biliary cirrhosis, while second patient had Wegener granulomatosis. The 2 patients responded to therapy with oral dapsone and prednisone, respectively. CONCLUSIONS The atypical presentation of neutrophilic dermatosis in 2 patients with clinical features of dermatomyositis and intercurrent autoimmune-mediated illnesses may suggest an expansion in the clinical spectrum of parainflammatory neutrophilic dermatoses. The finding of a neutrophilic dermatosis in a biopsy specimen from a patient without a classic clinical presentation should invoke a thoughtful search for underlying immune complex-mediated systemic disease.

An immunohistochemical comparison between MiTF and MART‐1 with Azure blue counterstaining in the setting of solar lentigo and melanoma in situ*

Background: Evaluation of cutaneous pigmented lesions can be diagnostically challenging and represents an activity often supplemented by immunohistochemistry. Immunohistochemical studies typically employ 3,3′‐diaminobenzidine (DAB) resulting in brown staining of both melanocytes and melanin. Difficulty may thus arise in distinguishing different cell types in heavily melanized lesions. Azure blue counterstaining has been used in conjunction with melanoma antigen recognized by T‐cells (MART‐1) to differentiate melanocytes from melanin by highlighting the latter blue‐green. Microphthalmia transcription factor (MiTF) represents an alternative immunomarker that shows nuclear reactivity, which facilitates ease of interpretation.