American Journal of Dermatopathology

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No abstract text is available yet for this article.

No abstract text is available yet for this article.

No abstract text is available yet for this article.

Cervical chondrocutaneous branchial remnant is a rare congenital developmental anomaly typically located on the lateral neck. Histologically, it has the appearance of an accessory tragus demonstrating a central cartilaginous core with surrounding fibrosis located in the subcutaneous tissue. The condition has been associated with a variety of congenital anomalies, particularly involving the auditory, cardiovascular, and visual systems. Given that research-based evidence related to cervical chondrocutaneous branchial remnant in dermatology literature is sparse, we present this case to raise more awareness about this entity among dermatopathologists and review the different histopathologic presentations and possible associated anomalies...

BACKGROUND: Atypical fibroxanthoma (AFX) is a dermal-based, low-grade neoplasm with no specific lineage of differentiation. The occurrence of AFX with osteoclast-like giant cells is exceptionally rare. Less than 20 cases have been reported in the literature. CASE PRESENTATION: A 77-year-old man with a medical history of multiple basal and squamous cell carcinomas of the skin, presented with a progressively growing erythematous nodule on the sun-damaged right central parietal scalp...

Eccrine duct fibroadenomatosis is a reactive histological phenomenon observed in a variety of inflammatory and neoplastic pathologies. We report a case of a ROS1 fusion angiomatoid Spitz nevus with associated acrosyringeal hyperplasia and a syringoma-like ductal proliferation in a young female patient.

Leukemia cutis corresponds to skin infiltration by malignant hematopoietic cells. It is most commonly reported in acute myeloid leukemia, particularly in subtypes with a monocytic component. Its clinical manifestations are extremely variable, and histopathologic diagnosis of cutaneous leukemic infiltrates may be challenging. We report the first case of cutaneous, that is, extramedullary, aleukemic relapse of acute myeloid leukemia within an unusual chilblain-like eruption that imposed a challenging clinical and histopathologic diagnosis...

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Sudden conjunctivitis, lymphopenia, and rash combined with hemodynamic changes (SCoRCH) is a recently described hypersensitivity reaction to trimethoprim-sulfamethoxazole. To date, only 1 case of histologic findings in SCoRCH has been reported, revealing a superficial perivascular dermatitis. In this article, we present a 53-year-old woman with a four-day history of a widespread, confluent, erythematous, and dusky rash after exposure to trimethoprim-sulfamethoxazole. Histologic examination revealed a vacuolar interface dermatitis with several apoptotic keratinocytes at multiple levels of the epidermis, similar to an erythema multiforme-like presentation...

Signet-ring cell/histiocytoid carcinoma (SRCHC) is a rare appendageal tumor, mainly considering eyelids, more rarely axillae. This article describes 2 novel SRCHC cases of 71- and 66-year-old men and systematically reviews the literature on SRCHC. Of all cases reported in the literature, 73 (91.2%) were men and 7 (8.8%) were women. The median age at diagnosis was 71 years. Skin changes were located in the eyelids (68%) and axillae (32%). In all tested cases, SRCHC cells expressed CK7, CKAE1/AE3, EMA, CAM5.2, and AR and PIK3CA mutations...

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Vitamin D receptor (VDR) exerts its biological effects when it heterodimerizes to a nuclear receptor of the retinoid family called retinoid X receptor α (RXRα), stimulating or inhibiting DNA transcription. VDR stimulation by vitamin D analogs led to in vitro antiproliferative effects, and experimental RXRα knockout led to loss of proliferation control in melanoma cells. The aim of this study was to determine VDR and RXRα positivity in melanocytic lesions, compared with normal skin species...

GLI1 gene alterations (rearrangement or amplification) have been found in several bone and soft tissue tumors including pericytic tumors, gastric plexiform fibromyxoma, gastroblastoma, and a various group of epithelioid tumors with regional recurrence or distant metastasis. In this article, we describe a case of primary cutaneous epithelioid mesenchymal tumor harboring hitherto not reported ATP2B4::GLI1 gene fusion. A 42-year-old man presented with a growing firm lesion on the left postauricular scalp. Microscopically, the shave biopsy specimen revealed a dermal-based nodular proliferation of relatively monotonous epithelioid cells with round to ovoid nuclei and pale eosinophilic cytoplasm, accompanied by prominent stromal vasculature...

Spindle cell squamous cell carcinoma with myxoid stroma is a rare variant of squamous cell carcinoma with sarcomatoid morphology. We report a case of a 75-year-old woman with an ulcerated polypoid cutaneous mass in the perianal area. The patient had a history of clear cell renal cell carcinoma. Microscopy revealed an invasive myxoid spindle cell carcinoma without the classic squamous cell carcinoma component. The immunohistochemical study demonstrated diffuse positive reactions for p63, AE1/3, and CK5/6. The tumor cells were negative for desmin, smooth muscle actin, S100, and CD34...

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Melanocytic matricoma is a rare benign pilar tumor characterized by matrical differentiation and interspersed dendritic melanocytes. It may show cellular atypia and brisk mitotic activity. Histological characterization of some lesions may be difficult. In addition, because the reported cases are few and have limited follow-up, there is insufficient experience to define outcome-based criteria for malignancy. Some cases of melanocytic matricoma with more prominent atypia have been reported as malignant, but their clinical behavior is uncertain...

Deep penetrating nevi (DPN), particularly those showing combined features, or combined deep penetrating nevi (CDPN), may show histopathological resemblance to blue nevus (BN) and melanoma. Preferentially Expressed Antigen in MElanoma (PRAME) is a marker that helps distinguish melanoma from benign melanocytic lesions. Lymphoid enhancer-binding factor 1 (LEF1) has been proposed to be used in conjunction with β-catenin for diagnosis of DPN. The immunohistochemical expression of PRAME and LEF1 was evaluated in 10 DPN (including 6 CDPN and 2 DPN-like proliferations with atypical features), 16 BN (including combined and cellular BN), and 2 melanomas with features of DPN or BN...

Nevus spilus, or speckled lentiginous nevus, is a relatively common lesion that presents at birth or in early childhood. It consists of a background tan patch, which appears similar to a café au lait macule or lentigo simplex on histology, studded with various types of nevi. Rarely, these nevi can undergo malignant transformation to melanoma. When melanoma develops within a heavily photodamaged nevus spilus, evaluating excision margins may be challenging because the combined histologic features of nevus spilus and severe dermatoheliosis can mimic melanoma in situ...