Garth R. Fraga

Tattoo‐associated keratoacanthomas: a series of 8 patients with 11 keratoacanthomas

Background: Keratoacanthoma is interpreted by many dermatopathologists in the United States as a form of squamous cell carcinoma that can spontaneously involute. Rare examples arising in tattoos have been reported in the literature.

Onychomatricoma: report of a case and its comparison with fibrokeratoma of the nailbed.

Onychomatricoma was first described in 1992 by Baran and Kint. Twenty cases have been reported to date, all of which are from Europe. This tumor has characteristic clinical, light microscopic, and ultrastructural features which have recently been refined andjustify its categorization as a novel tumor of the nail matrix. We examined a specimen sent in consultation by a large reference laboratory; despite improper orientation and absence of the involved nail plate, it had microscopic characteristics consistent with onychomatricoma. Soon thereafter, a second patient presented with a tumor arising in the nailbed that bore a superficial resemblance to onychomatricoma but showed the microscopic features of fibrokeratoma. We discuss the differentiation between these two lesions and point out that a distinction can be made even when incomplete material is submitted for review. To our knowledge, this is the first example of onychomatricoma to be reported from North America.

Blastic marginal zone lymphoma: a clinical and pathological study of 8 cases and review of the literature.

Introduction:Blastic transformation (BT) of marginal zone lymphoma or mucosa-associated lymphoid tissue lymphoma has been mainly reported in the spleen and stomach. Primary cutaneous marginal zone lymphoma that undergoes BT is rare and not well documented. We describe 8 patients with blastic primary cutaneous marginal zone lymphoma and compare the clinical, pathologic, and molecular findings of these patients with 10 cases previously reported in the literature. Results:The cases of blastic marginal zone lymphoma could be categorized into cases of de novo blastic marginal zone lymphoma and large-cell transformation arising in a background of a history of biopsy proven marginal zone lymphoma. The cases of de novo blastic marginal zone lymphoma occurred in elderly patients without any medical history. In each of the cases, the lesions were radiated, not treated, or treated with complete excision without any death due to lymphoma nor was there any evidence of extracutaneous dissemination. Large-cell transformation arising in background of marginal zone lymphoma typically occurred in patients who were younger; 2 of the 4 cases were immunocompromised. The clinical course in each of the cases was aggressive with 3 of the 4 patients succumbing to disseminated disease while 1 patient developed extracutaneous nodal disease. Phenotypically, there was an expression of CD5 in a total of 3 of the 8 cases and CD23 in 3 of the 8 cases. Commonality of B-cell clones was demonstrated in 2 cases where biopsies were available of both the less aggressive appearing marginal zone lymphoma and the transformed biopsies. Cytogenetic abnormalities associated with BT included a deletion of chromosome 7q in all cases tested. Conclusion:Large-cell transformation arising in a patient with a history of marginal zone lymphoma portends a worse prognosis, including death from disseminated disease, whereas a de novo presentation of blastic marginal zone lymphoma may define a clinical course similar to other forms of low-grade cutaneous B-cell lymphoma. The expression of CD5 and CD23 may define a phenotypic profile associated with BT. It is possible that marginal zone lymphomas associated with CD5 and CD23 positivity should be followed more closely and/or treated with radiation and/or complete excision.

Ex vivo dermoscopy of cutaneous biopsies for melanocytic neoplasms: a retrospective review of 517 cases with histopathologic correlation.

Abstract:Clinical dermoscopy has provided new insights into the diagnosis and classification of melanocytic neoplasms. There are only limited data on its applications in dermatopathology. In our laboratory, we routinely photograph all skin biopsies with ex vivo dermoscopy (EVD). We retrospectively reviewed 517 cutaneous biopsies with corresponding EVD images to determine whether EVD provides useful ancillary information in the histopathologic diagnosis of melanocytic neoplasms. Four hundred eighty-three cases (93.4%) yielded usable images. The lesions could be categorized according to a published dermoscopic classification system of melanocytic proliferations. Reticular pigmentation correlated with dysplastic nevi, globular pigmentation with congenital nevi, homogenous blue pigmentation with blue nevi, starburst peripheral globular pigmentation with Spitz nevi, and atypical pigment patterns with melanoma. Eighteen of 25 cases (72%) with ambiguous histopathology were assigned a more definite diagnosis when reviewed contemporaneously with EVD images. The surgical margins in 40 cases (7.7%) were reclassified when EVD images were included in the review. We found EVD to be a useful technique and advocate its use for diagnosis and clinical–pathologic correlation.

Diagnostic concordance rates in the subtyping of basal cell carcinoma by different dermatopathologists

There are numerous subtypes of basal cell carcinoma (BCC). Defining the histopathologic subtype is an essential element in patient management, but there is little known data regarding interobserver precision in subtyping BCC.

EGFR and MYC gene copy number aberrations are more common in squamous cell carcinoma than keratoacanthoma: a FISH study

Epidermal growth factor receptor (EGFR) and MYC genomic aberrations have been described in cutaneous squamous cell carcinoma (SCC) but have not been widely investigated in keratoacanthoma (KA). EGFR and MYC were evaluated by fluorescence in situ hybridization and immunohistochemistry in 8 verrucae, 19 involuting KA (IKA), 23 classic KA (CKA), 6 atypical KA (AKA) and 19 SCC. Increased EGFR gene copy number was seen in 9 of 23 CKA and 14 of 19 SCC (p = 0.03). Increased MYC gene copy number was observed in 7 of 23 CKA and 17 of 19 SCC (p = 0.0001). MYC gene amplification was more common in SCC than CKA (p = 0.005), while EGFR gene amplification was rare and not significant. MYC protein overexpression was identified in 6 of 23 CKA and 14 of 19 SCC (p = 0.005). There was no statistical difference in EGFR protein overexpression in SCC and CKA (p = 0.06). EGFR and MYC aberrations were rare in IKA. AKA showed EGFR and MYC anomalies at an incidence intermediate between CKA and SCC. EGFR and MYC gene copy number aberrations are more common in SCC than KA. The incidence of aberrations parallels the degree of cytologic atypia in KA.

Cutaneous metastasis of ovarian carcinoma with shadow cells mimicking a primary pilomatrical neoplasm.

Shadow cells are characteristic of pilomatricoma, although they have been described in other cutaneous and visceral neoplasms, particularly endometrioid adenocarcinomas of the female genital tract. We describe a metastasis of an ovarian endometrioid adenocarcinoma with shadow cells to the skin that was initially misinterpreted as a pilomatricoma. We compare the histology of the ovarian neoplasm to 21 pilomatricomas. This is the first reported case of a cutaneous metastasis of a visceral neoplasm mimicking a primary pilomatrical neoplasm.

Necrotizing infundibular crystalline folliculitis manifesting as a perforating mucinosis: a case report.

: Necrotizing infundibular crystalline folliculitis (NICF) is a rare entity manifesting as waxy folliculocentric papules comprised of filamentous birefringent crystalline deposits. We report a case of NICF in an 85-year-old man, presenting as gritty, cream-colored, and erythematous papules across the midline back. Biopsy demonstrated a pale plug comprised of copious mucin. The diagnostic crystals were initially overlooked because of softening of the paraffin block with 10% ammonia solution, which dissolved the crystals in the initial sections. X-ray microanalysis confirmed the organic nature of the crystals. This is the first report of NICF from North America. Our case highlights the presence of mucin in some cases of NICF and serves as a cautionary tale on the pitfalls of postprocessing artifacts in the histology laboratory.

Large cell acanthoma: a variant of solar lentigo with cellular hypertrophy.

Large cell acanthoma (LCA) is an epidermal proliferation of enlarged keratinocytes. There is a lack of consensus on whether it represents a unique neoplasm or not. To determine whether it is a variant of solar lentigo, we compared macroscopic, microscopic and immunophenotypic attributes of LCA with conventional solar lentigo, seborrheic keratosis, actinic keratosis and Bowen disease.

Localized chronic fibrosing vasculitis in a tattoo: a unique adverse tattoo reaction.

Decorative tattoos are associated with a variety of adverse cutaneous reactions. We describe a unique fibrosing vasculitic reaction to red tattoo ink. The histopathology was similar to that in localized chronic fibrosing vasculitis (LCFV), but sharply limited to sites of red tattoo ink injection and associated with florid verrucoid epidermal hyperplasia. LCFV has been described in a broad variety of slowly progressive disorders with a firm consistency such as erythema elevatum diutinum, plasma cell granuloma, granuloma faciale, and IgG4-associated sclerosing diseases. It has been hypothesized that LCFV is the result of maladaptive immune reaction with failure to clear the causative antigen. To the best of our knowledge, this is the first case of LCFV associated with tattoo. We speculate on the implications our case holds for the pathogenesis of LCFV.