Cutaneous pseudosarcomatous polyp: a recently described lesion

Lymphedematous Fibroepithelial Polyp Without Associated Condom Catheter Use: A Case Report With Review of the Literature

ABSTRACT

Lymphedematous fibroepithelial polyps are rare proliferations involving the glans penis typically associated with chronic condom catheter usage. To the best of our knowledge, less than 20 cases have been reported in the literature with relatively similar clinical presentation. Herein, we report a case of lymphedematous fibroepithelial polyp not associated with condom usage in a 74-year-old man treated with surgical excision. On histopathological examination, the lesion displayed a hypocellular proliferation of spindled and stellate fibroblasts with intermixed Touton-like giant cells embedded within an edematous stroma with thickened vasculature. Immunohistochemical profiling exhibits strong immunoreactivity for smooth muscle actin, weak positivity for factor XIIIa, and no reactivity for CD34 or desmin. We also conducted a review of the reported range of clinical and histopathological features of this entity in addition to the various hypotheses regarding its pathogenesis. We hope to increase awareness and accurate diagnosis of this entity, which could affect clinical management.

DICER1-Mutated Botryoid Fibroepithelial Polyp of the Parotid Duct: Report of the First Case

DICER1, a member of the ribonuclease III family, is involved in the biogenesis of microRNAs and, hence, it influences gene expression regulation. DICER1 germline (associated with the inherited DICER1 syndrome) or somatic mutations have been linked to tumorigenesis in histogenetically diverse benign and malignant neoplasms in different organs including pleuropulmonary blastoma, cystic nephroma, embryonal rhabdomyosarcoma, nasal chondromesenchymal hamartoma, poorly differentiated thyroid carcinoma, thyroblastoma, intracranial sarcoma and gonadal Sertoli-Leydig cell tumors in addition to others. Moreover, rare botryoid (giant) fibroepithelial polyps may harbor this mutation. Herein, we describe the first reported case of a DICER1-mutated botryoid fibroepithelial polyp occurring within the parotid duct of a 65-year-old female who has no other features or family history of the DICER1 syndrome. Based on its distinctive morphology, we tested this lesion specifically for DICER1 mutations and confirmed the presence of a pathogenic DICER1 variant with a low allele frequency, consistent with a somatic mutation.

Cutaneous symplastic hemangioma: A series of four cases

Symplastic hemangiomas (SH) are benign vascular lesions that show atypia in vascular smooth muscle and interstitial cells with sparing of endothelial cells. We present four cases of this rare tumor. The patients (two males; two females) ranged in age from 57 to 83 years (median 74); lesions were located on the leg (n = 3) and back (n = 1), and ranged from 6 to 8 mm. SH were well-circumscribed and dermal-based, often with an epidermal collarette (3/4). They were characterized by the presence of variably atypical, hyperchromatic/pleomorphic epithelioid to spindled cells within vascular walls (3/4) and/or perivascular stroma (4/4). Atypical multinucleated cells were present in three of four cases. The overall mitotic rate was low (0-2 mitotic figures per 10 HPFs; mean 0.75 per 10 HPFs), but atypical mitotic figures were seen in two of four cases. Atypical cells were negative for SMA (0/2), desmin (0/2), AE1/3 (0/2), and CAM5.2 (0/1). ERG, CD31, and CD34 stains were positive in endothelial cells but negative in atypical cells (4/4). Lesional cells and vessels were negative for podoplanin (3/3). Symplastic hemangioma is a benign tumor with bizarre atypia that may be mistaken for malignancy. We present four cases of this rare entity to increase awareness of this tumor and discuss the differential diagnosis.

Benign soft tissue lesions that may mimic malignancy

Soft tissue lesions which mimic malignancy (pseudosarcomas), represent a significant diagnostic challenge for pathologists. Many features often associated with malignancy including rapid and infiltrative growth, increased cellularity and mitotic activity, and nuclear pleomorphism are present in benign and reactive conditions. This review highlights repair reactions including nodular fasciitis, proliferative fasciitis/myositis, intravascular papillary endothelial hyperplasia, and fat necrosis; lipoma and spindle cell/pleomorphic lipoma; fibroepithelial stromal (pseudosarcomatoid) polyp; phosphaturic mesenchymal tumor; and myxoma. While not inclusive of every pseudoneoplastic soft tissue lesion, this review emphasizes important diagnostic pitfalls and stresses the value of clinical, pathologic, and radiologic correlation.

Cellular pseudosarcomatous fibroepithelial stromal polyp of the vagina during pregnancy: a lesion that is overdiagnosed as a malignant tumor

Fibroepithelial stromal polyp (FSP) is a benign lesion that can occur at various sites, including the lower female genital tract. In rare cases, however, it may exhibit hypercellularity, bizarre cytomorphological features, and atypical mitoses resulting in an overdiagnosis as a malignant tumor despite its benign clinical course. Recently, we experienced one case of a 30-year-old pregnant woman with cellular pseudosarcomatous FSP that was initially diagnosed as a malignant fibrous histiocytoma at a primary clinic. In addition to describing the rare features of this case, we wish to increase awareness about this benign lesion which will be essential for avoiding unnecessary radical surgery or chemoradiation treatment.

Selected Pseudoneoplastic Lesions of the Skin

Context.—Pseudoneoplastic cutaneous lesions are diverse, not only morphologically but also with respect to their causes and cellular lineages. They include proliferations of epithelial, as well as mesenchymal, elements.

Objective.—This review aims to consider selected lesions in the aforementioned groups, contrasting them with histologically similar neoplasms of the skin in a differential diagnostic setting.

Data Sources.—Information used in assembling this discussion was drawn from the published literature on cutaneous pseudoneoplasms, using an Internet-based search engine. The authors' collective experience was also used in writing this review.

Conclusions.—Sufficient clinical and morphologic differences exist in virtually all instances to separate pseudoneoplastic cutaneous proliferations from the tumors that they imitate.