Epithelioid Fibrous Histiocytoma With Chondroblastoma-Like Features: A Report of a Rare Entity and Discussion of Related Diagnostic Challenges.

ABSTRACT: Epithelioid fibrous histiocytoma (EFH) is an uncommon benign skin lesion. It is distinct from FH by virtue of its recurrent anaplastic lymphoma kinase (ALK) gene rearrangements and immunohistochemical expression of ALK protein. It often poses a challenge in interpretation. Clinically, it is characterized by a flesh-colored papule/nodule on an extremity of a young to middle-aged individual. Microscopically, it is represented by a circumscribed dermal papule/nodule composed of sheets of plump epithelioid cells, forming whorled aggregates around numerous intralesional vessels. Immunohistochemistry, notably ALK positivity and relevant negative stains, serves to distinguish EFH from its morphological mimics. Rare examples of chondroblastoma-like EFH and EFH with osseous metaplasia are recorded in the literature. Our case is of a 58-year-old man who attended an oculoplastic surgeon because of an exophytic cutaneous nodule on the right upper eyelid. The lesion was excised. Microscopically, it displayed morphological and immunohistochemical features of EFH. Of interest, discrete foci of chondro-osseous change, including chondroblastoma-like pericellular calcification, osteoid formation, and osteoclast-like giant cells, were noted throughout the lesion. A diagnosis of EFH with chondroblastoma-like features was made. Of interest, the changes observed in this EFH serve to link the previously reported examples of pure chondroblastoma-like EFH and EFH with osseous metaplasia. This morphological variant of EFH adds to the existing diagnostic challenge presented by these lesions, particularly in the distinction from other calcifying tumors of the skin.

Recurrent IgG4-related tubulointerstitial nephritis concurrent with chronic active antibody mediated rejection: A case report.

IgG4-related disease is a relatively newly described entity that can affect nearly any organ, including the kidneys, where it usually manifests as tubulointerstitial nephritis (IgG4-TIN). The diagnosis can be suggested by characteristic histological features, including an inflammatory infiltrate with increased IgG4-positive plasma cells associated with "storiform" fibrosis. Serum IgG4 is usually elevated. In the native kidney and other organs, there is typically a brisk response to treatment with immunosuppression. Recurrence of IgG4-TIN after renal transplant has not been described in the literature. Here, we describe the first case of recurrent IgG4-TIN in a young patient concomitant with chronic active antibody mediated rejection five years after kidney transplant. Recurrent IgG4-TIN could be diagnosed by the characteristic histopathologic features and increased IgG4-positive plasma cells. Despite maintenance immunosuppression, this disease may recur in the kidney allograft.

A case report of a localized reticular erythematous mucinosis like eruption of the lower legs mimicking cutaneous larvae migrans.

Reticular erythematous mucinosis is an uncommon type of cutaneous mucinosis. Typically, reticular erythematous mucinosis affects middle-aged women and usually appears as papules and plaques on the mid-upper trunk. Histologically, biopsies of reticular erythematous mucinosis reveal increased deposition of dermal mucin and perivascular lymphocytic inflammation. Infrequently, reticular erythematous mucinosis has been reported in males and in atypical locations other than the trunk. In these instances, reticular erythematous mucinosis can present a diagnostic challenge clinically and histologically. This case describes the clinical and histologic findings of a localized variant of reticular erythematous mucinosis in a 65-year-old male patient.

A case of multifocal cutaneous alternariosis in a patient with hairy cell leukemia.

We present a case of multifocal cutaneous alternariosis in a 69-year-old man with hairy cell leukemia. The patient presented with painful, violaceous nodules of the lower extremities and left forearm. His physical examination was otherwise normal. Biopsy specimens were submitted first for histopathological examination, followed by microbiological testing. Histopathology showed epidermal hyperplasia, intraepidermal abscess formation, and intracellular and extracellular fungal elements. Subsequent microbiological investigations, including fungal culture and polymerase chain reaction (PCR), isolated Alternaria alternata. The patient was treated for cutaneous alternariosis with itraconazole for 12 weeks and demonstrated significant improvement of the lesions. This case highlights the role of dual histopathological and microbiological laboratory investigation in suspected opportunistic cutaneous mycoses.

Les chercheurs présentent un cas d'alternariose cutanée multifocale chez un homme de 69 ans atteint d'une leucémie à tricholeucocytes. Le patient a consulté à cause de nodules violacés et douloureux sur les extrémités inférieures et l'avant-bras gauche. Son examen physique était autrement normal. Des biopsies ont été d'abord soumises en vue d'un examen histopathologique, puis de tests microbiologiques. L'histopathologie a révélé une hyperplasie épidermique, la formation d'abcès épidermiques et des éléments fongiques intracellulaires et extracellulaires. Les explorations microbiologiques subséquentes, y compris les cultures fongiques et l'amplification en chaîne par polymérase, ont isolé l'Alternaria alternata. Le patient a reçu un traitement de 12 semaines à l'itraconazole pour vaincre une alternariose cutanée, et ses lésions ont considérablement diminué. Ce cas souligne l'intérêt de conjuguer l'exploration histopathologique à l'exploration microbiologique dans les cas présumés de mycose opportuniste.