Kord Honda

Surgical management of congenital dermatofibrosarcoma protuberans

Congenital dermatofibrosarcoma protuberans (DFSP) is a rare tumor with varying clinical presentations that is commonly misdiagnosed. Treatment of congenital DFSP is complicated by delays in diagnosis and its propensity for subclinical spread. Of 61 reported cases, 11 (18%) were treated with Mohs micrographic surgery (MMS) and 46 (75%) were treated with wide local excision (WLE). One case was treated with imatinib, and the remaining 3 did not differentiate between receiving MMS or WLE. In the cases of congenital DFSP treated with MMS the clearance rate was 100% with an average follow-up of 4.3 years. The clearance rate seen with WLE was 89% with an average follow-up period of 1.9 years. The average margins taken during MMS (1.7 cm) were smaller than those taken with WLE (2.8 cm). Fifty percent of cases with available follow-up undergoing WLE required multiple surgeries. Based on superior cure rates with long-term follow-up, smaller surgical margins, and fewer surgical sessions, MMS should be considered as first-line treatment for congenital DFSP.

Update on primary mucosal melanoma

Mucosal melanomas are aggressive cancers of mucosal surfaces with clinical and pathologic characteristics distinct from cutaneous melanomas, warranting different staging systems and treatment approaches. Surgical resection is performed frequently for the primary tumor, although the utility of lymph node surgery and radiation therapy is not established. Therapies targeted against C-KIT activating mutations, identified in many mucosal melanomas, are emerging as promising treatments.

Growth on demand: Reviewing the mechanobiology of stretched skin

Skin is a highly dynamic, autoregulated, living system that responds to mechanical stretch through a net gain in skin surface area. Tissue expansion uses the concept of controlled overstretch to grow extra skin for defect repair in situ. While the short-term mechanics of stretched skin have been studied intensely by testing explanted tissue samples ex vivo, we know very little about the long-term biomechanics and mechanobiology of living skin in vivo. Here we explore the long-term effects of mechanical stretch on the characteristics of living skin using a mathematical model for skin growth. We review the molecular mechanisms by which skin responds to mechanical loading and model their effects collectively in a single scalar-valued internal variable, the surface area growth. This allows us to adopt a continuum model for growing skin based on the multiplicative decomposition of the deformation gradient into a reversible elastic and an irreversible growth part. To demonstrate the inherent modularity of this approach, we implement growth as a user-defined constitutive subroutine into the general purpose implicit finite element program Abaqus/Standard. To illustrate the features of the model, we simulate the controlled area growth of skin in response to tissue expansion with multiple filling points in time. Our results demonstrate that the field theories of continuum mechanics can reliably predict the manipulation of thin biological membranes through mechanical overstretch. Our model could serve as a valuable tool to rationalize clinical process parameters such as expander geometry, expander size, filling volume, filling pressure, and inflation timing to minimize tissue necrosis and maximize patient comfort in plastic and reconstructive surgery. While initially developed for growing skin, our model can easily be generalized to arbitrary biological structures to explore the physiology and pathology of stretch-induced growth of other living systems such as hearts, arteries, bladders, intestines, ureters, muscles, and nerves.

Phase II Trial of Imatinib in AIDS-Associated Kaposi's Sarcoma: AIDS Malignancy Consortium Protocol 042

PURPOSE Kaposis sarcoma (KS) is a disease of multifocal vascular proliferation that requires infection with KS herpes virus (KSHV/HHV-8). Activation of the c-kit and platelet-derived growth factor (PDGF) receptors by autocrine/paracrine mechanisms follows endothelial cell KSHV infection. In a pilot study, imatinib, a c-kit/PDGF-receptor inhibitor, induced partial regression of AIDS-associated KS (AIDS-KS) in five of 10 patients. PATIENTS AND METHODS This multicenter phase II study was designed to estimate the response rate to imatinib in AIDS-KS. Secondary objectives included investigation of predictors of response and imatinib pharmacokinetics in patients on antiretrovirals. Patients received imatinib 400 mg/day by mouth for up to 12 months with dose escalation up to 600 mg/day at 3 months if their disease was stable. RESULTS Thirty patients were treated at 12 AIDS Malignancy Consortium sites. Ten patients (33.3%) achieved partial response, six (20%) had stable disease, and seven (23.3%) exhibited KS progression. Nine patients completed 52 weeks of imatinib therapy. The median treatment duration was 22.5 weeks. Only five patients (16.7%) discontinued therapy owing to adverse events. Antiretroviral regimens did not significantly alter imatinib metabolism. Activating mutations in PDGF-R and c-kit were not found at baseline or at disease progression. We found no correlation with response with changes in any of the candidate cytokines. CONCLUSION Imatinib has activity in AIDS-KS. Pharmacokinetic interactions with antiretroviral drugs did not correlate with toxicity. Thirty percent of patients showed long-term clinical benefit and remained on imatinib for the entire year. These results suggest imatinib is well tolerated and may be an alternative therapy for some patients with AIDS-KS.

Merkel Cell Polyomavirus Small T Antigen Induces Cancer and Embryonic Merkel Cell Proliferation in a Transgenic Mouse Model

Merkel cell polyomavirus (MCV) causes the majority of human Merkel cell carcinomas (MCC) and encodes a small T (sT) antigen that transforms immortalized rodent fibroblasts in vitro. To develop a mouse model for MCV sT-induced carcinogenesis, we generated transgenic mice with a flox-stop-flox MCV sT sequence homologously recombined at the ROSA locus (ROSA sT), allowing Cre-mediated, conditional MCV sT expression. Standard tamoxifen (TMX) administration to adult Ubc CreERT2; ROSA sT mice, in which Cre is ubiquitously expressed, resulted in MCV sT expression in multiple organs that was uniformly lethal within 5 days. Conversely, most adult Ubc CreERT2; ROSA sT mice survived low-dose tamoxifen administration but developed ear lobe dermal hyperkeratosis and hypergranulosis. Simultaneous MCV sT expression and conditional homozygous p53 deletion generated multi-focal, poorly-differentiated, highly anaplastic tumors in the spleens and livers of mice after 60 days of TMX treatment. Mouse embryonic fibroblasts from these mice induced to express MCV sT exhibited anchorage-independent cell growth. To examine Merkel cell pathology, MCV sT expression was also induced during mid-embryogenesis in Merkel cells of Atoh1 CreERT2/+; ROSA sT mice, which lead to significantly increased Merkel cell numbers in touch domes at late embryonic ages that normalized postnatally. Tamoxifen administration to adult Atoh1 CreERT2/+; ROSA sT and Atoh1 CreERT2/+; ROSA sT; p53f lox/flox mice had no effects on Merkel cell numbers and did not induce tumor formation. Taken together, these results show that MCV sT stimulates progenitor Merkel cell proliferation in embryonic mice and is a bona fide viral oncoprotein that induces full cancer cell transformation in the p53-null setting.

Follicular center helper T-cell (TFH) marker positive mycosis fungoides/Sezary syndrome

We identified 11 patients with CD10(+) cutaneous T-cell lymphoma by flow cytometry. All cases were CD4(+) and CD8(−). Three patients had extensive lymphadenopathy, systemic symptoms and an aggressive clinical course consistent with angioimmunoblastic T-cell lymphoma or peripheral T-cell lymphoma. However, 8 of the 11 patients had a prolonged disease course with gross morphology, histology and tumor cell phenotype indistinguishable from mycosis fungoides or Sezary syndrome. Immunohistochemical studies confirmed CD10 expression in seven of the eight cases and revealed the lymphoma cells were Bcl-6(+), PD-1(+), and EBV(−). Two had significant expression of CXCL-13(+). The findings indicate that lymphoma cells from mycosis fungoides or Sezary syndrome may express follicular center helper T-cell markers CD10, Bcl-6, and PD-1 and occasionally CXCL-13. The expression of these markers in some cases of mycosis fungoides/Sezary syndrome suggests follicular center helper T-cell differentiation and may lead to confusion in distinguishing mycosis fungoides/Sezary syndrome from other follicular center helper T-cell marker positive T-cell lymphomas with cutaneous manifestations.

The art and science of surgical margins for the dermatopathologist.

Abstract:Basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and primary cutaneous melanoma (PCM) are the major forms of skin cancer. Surgical excision is one of the most frequently utilized treatment modalities for these tumors. Methods: literature review. Results: recommendations for lateral surgical excision margin (LEM) for BCCs is 4 mm for low-risk BCCs and Mohs surgery or resection with complete circumferential peripheral and deep margin assessment for high risk. Recommended LEM is 4–6 mm for low-risk SCCs and Mohs surgery or resection with complete circumferential peripheral and deep margin assessment for high risk BCCs. If SCC or BCC is >20 mm in area L with no other high-risk factors and can be repaired primarily, 10-mm clinical margins may be used. Recommended LEM is 5 mm for melanoma-in-situ; 1 cm for PCM <1 mm (Breslow); 1–2 cm for PCM 1.01–2 mm (Breslow); and, 2–3 cm for high-risk PCM >2.01 mm (Breslow). Tumor subtype-specific recommendations for histologic margins are offered which provide the greatest degree of certainty regarding the completeness of excision. Conclusion: Recommendations can be made regarding appropriate surgical excision margins by classifying skin cancers as low-risk or high-risk based on histopathological and clinical factors. Ascertaining that histopathologic margins are free of tumor is not a perfect science and requires thoughtful sampling, grossing, and staining procedures.

A case of CD30+ nasal natural killer/T-cell lymphoma

Extranodal nasal natural killer (NK)/T-cell lymphoma is a very rare lymphoma characterized by strong association with Epstein-Barr virus infection, very aggressive clinical behavior, and poor prognosis. The typical phenotype of neoplastic natural killer cells in this entity is as follows: CD2+, CD56+, surface CD3-, cytoplasmic CD3epsilon+, and cytotoxic granule-associated protein positive. CD30 expression, a phenotype characteristic of anaplastic large-cell lymphomas, is not a typical feature of nasal NK/T-cell lymphomas. We describe the case of a 42-year-old woman with chronic nasal congestion and septal deviation who presented with progressive generalized tender erythematous plaques. A skin biopsy revealed an atypical angiocentric mononuclear cell infiltrate. Strong CD30 and CD3e immunoreactivities were noted in large atypical mononuclear cells within the infiltrate initially suggestive of a CD30+ T-cell lymphoma. However, flow cytometry of the skin lesion indicated that the cells were CD2+, CD4-, CD8-, and lacked surface CD3 more typical of a neoplasm of natural killer cells. Further studies revealed that the cells were CD56+, T-cell-restricted intracellular antigen-1+, and contained Epstein-Barr virus sequences consistent with a nasal-type NK/T-cell lymphoma. High titers of Epstein-Barr virus in the blood, evidence of sinonasal disease, and absence of a T-cell receptor gene rearrangement were additional features consistent with the diagnosis. The patient had a very aggressive clinical course and, despite combination chemotherapy, died 8 months after the onset of skin lesions. This case represents an example of nasal-type NK/T-cell lymphoma with expression of CD30. When presenting in the skin, the phenotypic and morphologic features of this lymphoma may lead to an erroneous diagnosis of a CD30+ large-T-cell lymphoma.

Sterol Intermediates of Cholesterol Biosynthesis Inhibit Hair Growth and Trigger an Innate Immune Response in Cicatricial Alopecia

Primary cicatricial alopecia (PCA) is a group of inflammatory hair disorders that cause scarring and permanent hair loss. Previous studies have implicated PPARγ, a transcription factor that integrates lipogenic and inflammatory signals, in the pathogenesis of PCA. However, it is unknown what triggers the inflammatory response in these disorders, whether the inflammation is a primary or secondary event in disease pathogenesis, and whether the inflammatory reaction reflects an autoimmune process. In this paper, we show that the cholesterol biosynthetic pathway is impaired in the skin and hair follicles of PCA patients. Treatment of hair follicle cells with BM15766, a cholesterol biosynthesis inhibitor, or 7-dehydrocholesterol (7-DHC), a sterol precursor, stimulates the expression of pro-inflammatory chemokine genes. Painting of mouse skin with 7-DHC or BM15766 inhibits hair growth, causes follicular plugging and induces the infiltration of inflammatory cells into the interfollicular dermis. Our results demonstrate that cholesterologenic changes within hair follicle cells trigger an innate immune response that is associated with the induction of toll-like receptor (TLR) and interferon (IFN) gene expression, and the recruitment of macrophages that surround the hair follicles and initiate their destruction. These findings reveal a previously unsuspected role for cholesterol precursors in PCA pathogenesis and identify a novel link between sterols and inflammation that may prove transformative in the diagnosis and treatment of these disorders.

Histologic Lichenoid Features in Oral Dysplasia and Squamous Cell Carcinoma

OBJECTIVE This study describes the occurrence of histopathologic characteristics of oral lichenoid mucositis in epithelial dysplasia and squamous cell carcinoma. STUDY DESIGN This retrospective review examined 352 histologic specimens of group 1 (mild to moderate dysplasia), group 2 (severe dysplasia or carcinoma in situ), and group 3 (squamous cell carcinoma) for correlation between 5 histologic characteristics frequently found in oral lichen planus and grade, age, gender, and oral subsite. RESULTS In this sample, 29% of all cases exhibited 3 or more lichenoid features. Lichenoid features were significantly more frequent in group 1 over group 2 lesions for cases meeting a minimum lichenoid threshold (P = .001). No statistically significant patterns were noted for age or gender. The buccal mucosa was significantly overrepresented (P = .039) and the floor of the mouth was significantly underrepresented (P = .049) in regard to lichenoid feature frequency. CONCLUSIONS This study confirms the frequent correlation of lichenoid characteristics in oral premalignant and malignant lesions.