Diffuse neurofibroma with hypertrichosis in a toddler.

Diffuse neurofibroma is a rare type of neurofibroma uncommonly reported in infancy. It is a slow growing tumor originating in the peripheral nerve sheath. We present the case of a 17-month-old boy with diffuse neurofibroma of the scalp associated with hypertrichosis. His genetic and clinical workup for neurofibromatosis was negative.

Scurvy: a rare case in an adult.

A 69-year-old man presented with unilateral calf pain, swelling, and erythematous rash. He was initially treated with antibiotics for suspected cellulitis. A venous duplex ultrasound, performed to exclude deep venous thrombosis, revealed multiple heterogeneous hypoechoic foci of unknown etiology throughout the calf musculature. His condition did not improve with antibiotics, instead progressing to a necrotic ulcer along the medial malleolus. Clinical suspicion of vascular insufficiency or vasculitis prompted an extensive imaging work-up. CT and MRI revealed the intramuscular abnormalities observed on previous ultrasound represented foci of intramuscular hemorrhage. Marrow signal abnormality was also noted in the proximal tibia. A punch biopsy of the skin rash ultimately demonstrated distorted hair follicles with perifollicular inflammation and hemorrhage concerning for scurvy. The diagnosis was confirmed by low vitamin C levels and dietary history. A resurgence of scurvy has occurred in the pediatric population in recent years. However, this diagnosis remains uncommon in adults, with limited reports of the potential advanced imaging findings in the current literature.

Cutaneous involvement in multiple myeloma (MM): A case series with clinicopathologic correlation.

BACKGROUND: Disease-specific skin lesions are rare in patients with multiple myeloma (MM). OBJECTIVE: We sought to further characterize the clinical and pathologic features of patients with cutaneous involvement with MM. METHODS: We identified 13 patients with cutaneous lesions of MM. RESULTS: Cutaneous lesions consisted of pink, red, and violaceous papules, nodules, and/or plaques that varied in size. Histopathology revealed atypical plasma cells with occasional plasmablastic features. MM had aggressive biologic features and was at an advanced stage in the majority of patients. Despite aggressive management, including chemotherapy and stem-cell transplantation, most patients died of progressive disease within a few months after the development of cutaneous lesions. LIMITATIONS: The study group was relatively small. CONCLUSIONS: Cutaneous involvement with MM is associated with aggressive biologic behavior and short survival.

Umbilical Granuloma in a 2-Month-Old Patient: Histopathology of a Common Clinical Entity.

Umbilical granulomas are the most common anomaly of the umbilicus in neonates and infants. These lesions are characterized by an overgrowth of granulation tissue that persists at the base of the umbilical cord after its separation. Histologically, they consist of granulation tissue, which is composed of fibroblasts, inflammatory cells, and vascular endothelial cells set in an edematous stroma. Although umbilical granulomas are commonly seen clinically, there are no reports of their histopathology in the literature. The authors present the histology of this clinical finding in a 2-month-old infant, as it is important for the pathologist to be aware of this benign entity and distinguish it from other umbilical anomalies that may be of greater clinical significance.

Gamma-delta T-cell lymphoma arising in a long-standing cutaneous plaque.

The precise classification and characterization of primary cutaneous gamma-delta T-cell lymphoma (PCGD-TCL) has been hindered by clinical and morphologic features that overlap with other lymphomas, especially subcutaneous panniculitis-like T cell lymphoma (SPTCL). The recent World Health Organization/European Organization for Research and Treatment of Cancer (WHO/EORTC) classification distinguishes the more aggressive PCGD-TCL from the usually indolent SPTCL, however. We report a 30-year-old woman with an indurated violaceous plaque on the left cheek that had been present for several years. Biopsies showed a dense lymphocytic infiltrate involving the subcutis and dermis that consisted mostly of small and medium-sized lymphocytes, some with irregular nuclear contours and dense chromatin. These cells were positive for TIA-1, TCR-gamma and CD8, but negative for beta-F1 and granzyme-B. Staging with positron emission tomography-computed tomography (PET/CT), CBC and bone marrow with flow cytometry identified lymphadenopathy as well as blood and marrow involvement by an abnormal TCRgd-positive T-cell proliferation (Ann Arbor Stage IV). The patient's history of a long-standing lesion in this case is unusual, in that gamma-delta T-cell lymphomas are typically rapidly progressive neoplasms. As such, it raises the possibility of 'transformation' of a long-standing inflammatory process into an overt lymphoma.

Expression of CK7, Cam 5.2 and Ber-Ep4 in cutaneous squamous cell carcinoma.

BACKGROUND: Cytokeratin 7 (CK7) and Cam 5.2 are often used to differentiate extramammary Paget's disease (EPD) from squamous cell carcinoma (SCC) in situ because they are generally considered to be expressed in the former but not in the latter. However, we have encountered CK7+ and Cam 5.2+ SCCs. METHODS: We evaluated CK7, Cam 5.2 and Ber-Ep4 expression in SCC and EPD. RESULTS: We found significant CK7 and Cam 5.2 positivity in SCCs, particularly in those with a pagetoid pattern. Only one case expressed Ber-Ep4. CONCLUSIONS: We conclude that CK7 and Cam 5.2 expression may occur in SCC. A panel including Ber-Ep4 is advisable for immunohistochemical differentiation of EPD from SCC.

Impact of trainee experience on shave biopsy specimen size.

BACKGROUND: Skin biopsies are crucial for the diagnosis of many cutaneous pathologies, yet specimen adequacy is essential for definitive diagnosis. Recent literature has noted a trend in decreasing biopsy size over time, which has created concern over implications regarding adequacy for diagnosis. METHODS: This study sought to evaluate if clinician training length or type of residency training impacted the average biopsy size and sample adequacy. Dermatopathology reports for shave biopsies between January 1, 2021, and June 30, 2021, at Penn State Health were queried through PathNet, the software application for pathology reports in this health system's electronic medical record system. Biopsy dimensions, volume, diagnosis, location, clinician training level, and descriptions of evaluation of deeper sections (recuts) and superficial sampling were recorded for each biopsy. Basic statistical calculations were performed to assess the mean and standard deviation for biopsy sizes per clinician group. RESULTS: Differences in biopsy size between training levels were statistically significant despite qualitatively similar biopsy locations and final diagnosis categories for each clinician training group. After evaluating measures for sample adequacy, our data showed significantly smaller biopsies; however, overall frequencies were minimal. Additionally, more inadequate specimens were noted for clinician groups with the least amount of dermatology experience. CONCLUSIONS: The results of this study identify a correlation with decreasing biopsy size amidst increased experience in dermatology training but find no evidence to support that this trend currently threatens sample adequacy.

Dermal dendritic cells in psoriasis, nummular dermatitis, and normal-appearing skin.

BACKGROUND: The reason psoriasis (PSO) favors extensor skin is unknown. We hypothesized that PSO may involve extensor skin preferentially because of differences in the number or type of dermal dendritic cells (dDCs) between flexural and extensor skin. OBJECTIVE: We sought to compare dDC type and distribution in normal-appearing flexural and extensor skin, PSO, and nummular dermatitis (ND). METHODS: Using immunohistochemical markers, the number, distribution, and type of Langerhans cells, myeloid dendritic cells (DCs), and plasmacytoid DCs was compared in normal-appearing skin, PSO, and ND. RESULTS: Significant differences in dDC density were not identified between flexural and extensor skin, although extensor skin contained fewer CD11a(+) and CD11c(+) cells. Compared with normal-appearing skin, cells expressing CD11a, CD11c, CD123, CD303, and CD207 were increased in PSO. ND lesions showed similar increases. No significant difference between PSO and ND was evident with the exception of decreased S100A6(+) cells in PSO. LIMITATIONS: We did not study seasonal variation in DC density or assess nonlesional skin from patients with PSO. CONCLUSIONS: The data did not support the hypothesis that PSO favors extensor skin because of differences in DC localization. However, dDCs were significantly increased in PSO by comparison with normal-appearing skin, supporting existing evidence that they are involved in the overall pathogenesis of PSO.

Basal cell carcinoma characteristics as predictors of depth of invasion.

BACKGROUND: Pretreatment risk stratification of basal cell carcinoma (BCC) is largely based on histologic subtype reported from biopsy specimens. OBJECTIVE: We sought to determine the degree of concordance between characteristics identified on biopsy specimen and excision and to determine if histologic characteristics other than subtype correlated with depth of invasion. METHODS: Histologic specimens of 100 BCC biopsy specimens and corresponding excisions were reviewed. Anatomic site, histologic subtype, maximum depth of extension, contour of the lobules at the leading edge, elastosis characteristics, presence of necrosis, calcification, and ulceration were recorded. Concordance between biopsy specimens and their excisions with relation to depth of tumor lobules was analyzed. RESULTS: The concordance between the subtype of biopsy specimen and excision was 62%. Micronodular tumors had the greatest mean depth, followed by infiltrative, nodular, and superficial subtypes. Subtype reported from biopsy specimen (P = .0002) and excision (P < .0001) correlated to depth and was superior to age, contours of excision specimens, the presence of necrosis, and the extent of excisional solar elastosis. Gender, anatomic site, contours of biopsy specimens, elastosis color, elastosis type, the presence of ulceration, and calcification did not correlate with depth. LIMITATIONS: Selection bias is present as only standard excisions were included; BCCs treated by other methods were not examined. CONCLUSIONS: BCC subtype identified on biopsy specimen may not correlate with subtype identified on excision. Morphologic subtype has the highest correlation with depth and reporting should reflect the highest risk growth pattern if a biopsy specimen contains more than one pattern. Consideration should be given to reporting necrosis and degree of solar elastosis.

A congenital case of circumscribed acral hypokeratosis.

Circumscribed acral hypokeratosis is a disorder characterized by areas of erythematous depressed skin with distinct histopathological findings typically found on the palmar and plantar surfaces. Most patients are middle-aged women who report a multiyear history. We present an 10-year-old African American boy who had an asymptomatic, irregularly shaped erythematous lesion on his left medial foot that had been present since birth. A biopsy showed an abrupt, well-demarcated decrease in the thickness of the stratum corneum layer, with no parakeratosis, that was consistent with a diagnosis of circumscribed hypokeratosis. This represents the first pediatric and congenital case of circumscribed hypokeratosis reported. We review the literature and discuss the ramifications of a congenital case on understanding the etiology of circumscribed hypokeratosis.

Persistent melanocytic nevi: a review and analysis of 205 cases.

BACKGROUND: Melanocytic nevi can recur or persist if not completely excised and are capable of mimicking malignant melanoma, both clinically and histologically. OBJECTIVE: To characterize the impact of anatomic site, biopsy method, size, margin involvement and type of original melanocytic nevus on recurrence/persistence of melanocytic nevi. Secondarily, we sought to determine if the original type of melanocytic nevus could be determined solely from microscopic examination of the recurrent/persistent nevus. METHODS: One hundred and eighty-five patients with 205 persistent nevi were identified. Of these, 108 cases had original biopsy specimens available for review. Location, original biopsy size, biopsy method, margins and interval to recurrence were recorded for each. A group of 232 non-persistent nevi was established as a control population. RESULTS: There was a female predominance in persistent nevi with the back being the most common site for persistence. Dysplastic melanocytic nevi were the most likely to persist. Accurate determination of the original type of melanocytic nevus from microscopic examination of the persistent nevus was possible in only 67% of the cases. CONCLUSION: Clinicians should take larger and deeper biopsies of clinically dysplastic and conventional melanocytic nevi on the back to prevent recurrences. Grading atypia of the persistent melanocytic nevi is unreliable.

CD10-positive myxofibrosarcomas: a pitfall in the differential diagnosis of atypical fibroxanthoma.

CD10 is now commonly used to differentiate atypical fibroxanthoma (AFX) from melanoma, spindle cell and dedifferentiated variants of squamous cell carcinoma and leiomyosarcoma. However, we have encountered CD10-positive tumors that mimicked AFX but proved to be myxofibrosarcomas. The purpose of this study was to evaluate CD10 expression in a wide range of mesenchymal neoplasms that may involve the skin using tissue microarrays. Our results indicate that in addition to AFX, CD10 expression is common in myxofibrosarcomas, undifferentiated pleomorphic sarcomas, dermatofibromas and dermatofibrosarcoma protuberans. Myxofibrosarcomas commonly present in the skin and may be difficult to distinguish from AFX on small biopsies and CD10 positivity may confound the diagnostic difficulty.