Faculty Bibliography

We report an unusual case of cutaneous and mucosal hyperpigmentation in a thirty-six year old African American woman who was receiving capecitabine chemotherapy for Stage IV breast carcinoma. Possible etiologies for the hyperpigmentation are discussed. To our knowledge, this is the first reported case of capecitabine associated cutaneous hyperpigmentation

We report an instance of congenital granular cell tumors localized to the arm of a female infant. While granular cell tumors are well described during infancy as congenital epulis of the oral cavity, this case is unusual in both its location and histologic characteristics. The lesions, located around the antecubital fossa, were comprised of CD34-positive, S-100-negative granular cells. In addition, there were numerous eccrine glands in the upper dermis. The salient features of the case are discussed and reviewed in the context of the literature pertaining to this unusual entity

The perivascular epithelioid cell family of tumors (PEComas), defined by their co-expression of melanocytic and muscle markers, includes angiomyolipoma, lymphangioleiomyoma, and clear cell 'sugar' tumors of the lung, pancreas, and uterus. We present seven cases of a unique and previously unrecognized tumor of children and young adults, which represents a new addition to the PEComa group of tumors. Culled from three institutions over a 50-year period, all cases occurred in or immediately adjacent to the ligamentum teres and falciform ligament. Six patients were female and one male; their ages ranged from 3 to 21 years (median, 11 yrs). Tumor sizes ranged from 5 to 20 cm (median, 8 cm). All cases consisted of clear to faintly eosinophilic spindled cells arranged in fascicular and nested patterns. The cells had small but distinct nucleoli and low mitotic activity. Immunohistochemically, all cases were positive with antibodies to gp100 protein (HMB-45) and negative for S-100 protein. In three of the seven cases studied immunohistochemically, the tumors expressed smooth muscle actin, melan-A, microphthalmia transcription factor (MiTF), and myosin, but not desmin. No expression of the TSC2 gene product, tuberin, was seen in three cases. One case studied cytogenetically disclosed a t(3;10). Follow-up data, available in six of seven cases (median duration, 18 mos), showed five patients to be free of disease and one to have a radiographically presumed lung metastasis. We think these tumors comprise a new entity for which we propose the term 'clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres.' The differential diagnosis of these tumors includes clear cell sarcoma of tendons and aponeuroses, leiomyosarcoma, and angiomyolipoma

Dermatofibrosarcoma protuberans (DFSP) is a low grade, malignant spindle cell tumor with an infiltrative growth pattern and a high rate of local recurrence. This tumor's cell of origin is controversial. DFSP usually presents in adult life and is most frequently located on the trunk and proximal extremities. Although 10% to 15% of cases involve the head and neck, this tumor has not been previously described in the oral cavity

A case of basal cell carcinoma with giant cells of the central epithelial and surrounding stromal components is presented. The lesion was an 8-mm dome-shaped papule on the ear of a 66-year-old man. The giant cells of the epithelial component shared the immunophenotype of the more typical cells of the basal cell carcinoma (keratin, smooth muscle actin, and bcl-2 positive), whereas the stromal giant cells were positive only for bcl-2. This case represents a peculiar variant of pleomorphic basal cell carcinoma, the significance of which is unknown

Langerhans cell histiocytosis (LCH) is a disease with a broad spectrum of clinical presentations. All of the variants have in common the proliferation of cells which are morphologically, biochemically, and immunophenotypically indistinguishable from Langerhans cells. A retrospective study of three elderly patients revealed the unique presentation of cutaneous Langerhans cell histiocytosis limited to the genitalia. These cases produced a diagnostic challenge because of their unusual clinical presentation and their morphological similarity to certain other entities, including extramammary Paget's disease and malignant melanoma, which may also show S-100-positive atypical cells. All three cases showed infiltrates of histiocytic-appearing cells with folded nuclei and moderate amounts of cytoplasm which involved the epidermis, dermis, or both. Immunoperoxidase studies using antibody to S-100, CD1a and CD68 in each case showed positive staining

Halo reactions to melanocytic nevi are a well-recognized phenomenon. In contrast, halo reactions to Spitz's nevi have been reported only infrequently. Halo reactions may cause misdiagnosis of an otherwise benign nevus as melanoma because inflammatory cells sometimes obscure the architectural features of the underlying nevus, and may induce cytologic atypia. For Spitz's nevus where the distinction between malignancy and benignancy is already challenging, halo reactions compound the problem. We describe 17 examples of Spitz's nevus with halo reaction, and compare their immunohistochemical features with those of 'ordinary' halo nevi. Only 2 of 17 lesions demonstrated clinically apparent halos. Clinical follow-up was available for 12 of 17 cases. None of the 12 has persisted at the biopsy site or metastasized after an average 3.6-year follow-up period. Junctional, compound, intradermal, and combined types of Spitz's nevi were represented. All were characterized by symmetrical lymphocytic infiltrates which permeated the full thickness of the nevus, including junctional nests. Combined Spitz's nevi constituted more than one-half of examples in this series (9/17 cases). The combined Spitz's nevus included a combination of Spitz's nevus with either an ordinary (common, banal) nevus or a superficial congenital type nevus. In these combined Spitz's nevi, the lymphocytic response was often directed exclusively to the Spitz's nevic component. Important distinguishing features from malignant melanoma arising in a pre-existing nevus included symmetry and lateral circumscription of the spitzoid component, no large expansile-appearing aggregates of melanocytes, a decrease in size of nests with increasing dermal depth, a lack of mitotic figures among melanocytes at the base, and a symmetrical and diffusely permeative lymphocytic response. Although the combined Spitz's nevus with halo reaction sometimes appeared asymmetrical at scanning magnification, each component of the combination was symmetrical, when examined independently. Probably because of reactive atypia, nuclear maturation with progressive descent into the dermis was sometimes absent. There were no obvious differences in immunohistochemical staining patterns among 4 Spitz's nevi with halo reaction, 5 regressing melanomas, and 5 benign halo nevi when stained with antibodies to S100, HMB-45, OPD4, CD8, TIA-1, CD1a, CD68, and Ki-67

A commonly recognized feature of chronic radiation dermatitis is the presence of mesenchymal cells with large atypical nuclei known as radiation fibroblasts. Little is known about their lineage or potential for neoplastic transformation. To investigate these properties, we examined 16 biopsy specimens in which radiation fibroblasts were present with antisera to mesenchymal determinants (FXIIIa, CD34, HHF-35), a proliferation marker (Ki-67), and a tumor-suppressor protein that is overexpressed in many cancers (p53). Radiation fibroblasts were largely negative for the markers of lineage that we employed - only 2 of 16 specimens showed strong expression of FXIIIa, with weak expression in another case. Scattered radiation fibroblasts expressed CD34 in one case. HHF-35 (muscle specific actin) stained small, dendritic cells in the superficial dermis, but not radiation fibroblasts. P53 was not detected within radiation fibroblasts in any of our cases, but was overexpressed by endothelial cells in 2 cases. Ki-67 stained rare endothelial and interstitial cells but not radiation fibroblasts. Radiation fibroblasts are immunophenotypically distinct from dermal dendrocytes and myofibroblasts. They appear to be non-cycling cells, and do not express high levels of p53 despite their marked nuclear atypia. Their phenotype argues against their possible role as progenitors of atypical fibroxanthoma (AFX) and dermatofibrosarcoma protuberans (DFSP) which are associated with ionizing radiation-induced skin damage