Fibrohistiocytic skin tumors

Pulmonary Metastasising Aneurysmal Fibrous Histiocytoma: A Case Report, Literature Review and Proposal of Standardised Diagnostic Criteria

An aneurysmal fibrous histiocytoma is a rare cutaneous soft-tissue tumour which accounts for approximately 0.06% of all dermatopathologies. Metastasis is exceedingly uncommon, to the point that there have only been eight reported cases in the scientific literature. We present the case of a 25-year-old male with a primary aneurysmal fibrous histiocytoma located in the nuchal region which exhibited rapid growth and abrupt ulceration over a short time span and showed signs of locoregional aggressive infiltration. A subsequent histopathological analysis confirmed the presence of diffuse solid and cystic pulmonary metastases. Further genetic sequencing verified LAMTOR1-PRKCD fusion. This case report seeks to review the existing literature on aneurysmal fibrous histiocytoma, discuss the challenges of differential diagnosis and propose standardised diagnostic criteria.

Dermatofibrosarcoma protuberans in dermatological practice. Case report

Dermatofibrosarcoma protuberans (DFSP) is a mesenchymal neoplasm of fibrohistiocytic origin of moderate malignancy. The pathogenesis of DFSP involves chromosomal translocation, which leads to the formation of a fusion protein that promotes tumor growth due to increased production of platelet growth factor (PDGF). Clinically, it begins with an asymptomatic fibrous papule or firm plaques, which gradually over the course of several years become enlarged with the formation of asymmetrical multi-nodular structure of purple or red-brown color. The standards of diagnosis is a histological examination with the detection of a poor limited infiltrate indermis of a storiform architecture consisting of monomorphic spindle cells and diffuse CD34+ staining during immunohistochemistry. Complete surgical excision is considered the gold standard of treatment. Clinical case: female patient, 35 years old with a lesion in the form of a dense plaque in right subclavian area was examined by a dermatologist. The primary diagnosis was made as "morphea". In a year a slight growth of the lesion and the appearance of small firm nodules asymmetrically along the periphery were noted. According to the results of histological and immunohistochemistry studies the diagnosis of DFSP was made, the patient was referred to an oncologist for complete tumor removal.

A rare case of congenital plexiform fibrohistiocytic tumor of the foot in a 4-year-old boy: case report and literature review

The plexiform fibrohistiocytic tumor (PFHT) is an infrequent soft-tissue neoplasm with uncertain biological behavior. We report a rare congenital PFHT case in a 4-year-old boy, treated with wide excision and skin grafting. After a 52-month follow-up, no recurrence, regional or distant metastases were documented. A literature review on the management of PFHTs is reported.

Dermatomyofibroma-A rare mesenchymal tumor with maintained horripilation

Dermatomyofibroma is a rare mesenchymal tumor of skin. The major differential diagnosis is dermatofibrosarcoma protuberans. Both lesions are composed of spindle-shaped cells which are CD34-positive. In contrast to the malignant counterpart, the tumor cells in dermatomyofibroma are without any evidence of COL1A1-PDGFB gene rearrangement. We present a case of axillary dermatomyofibroma in a 31-year-old woman. A hitherto undescribed clinical phenomenon is a maintained horripilation in contrast to dermatofibrosarcoma protuberans.

Deep benign fibrous histiocytoma occurring in the kidney: Case report

RATIONALE

Deep benign fibrous histiocytoma (BFH) is relatively rare in contrast to superficial BFH involving the skin. Moreover, it was extremely rare for deep BFH occurring in the solid organ. To our knowledge, so far, only one case of deep BFH of the kidney was reported in English literature.

PATIENT CONCERNS

Herein, we report another case of deep BFH located in the kidney in a 88-year-old female. She was referred to our hospital for a severe pain in the right upper abdomen. Computed tomography revealed a round low-density shadow measuring 6 cm in the kidney.

DIAGNOSIS

The lesion was diagnosed as a deep BFH of the kidney, as the tumor was histologically predominately composed of bland ovoid cells arranged in a storiform pattern.

INTERVENTION

The patient underwent the total resection of the right kidney with the tumor in our hospital.

OUTCOMES

The postoperative course was uneventful. The patient was alive with no tumor recurrence or metastasis within 6 months of follow-up.

LESSONS

We present another case of deep BFH of the kidney. Because of the rarity, the tumor may be poorly recognized. The typical storiform pattern in histology may be helpful for diagnosis. This report serves to remind that deep BFH is also a differential diagnosis for a tumor with storiform pattern in the kidney.

Aneurysmal fibrous histiocytoma

Aneurysmal fibrous histiocytoma (AFH) is a type of fibrohistiocytic tumour. We present a case of a patient who presented with a skin papule on the thigh region. Histopathological examination following total excision of the lesion revealed an AFH. No sign of recurrence was present 6 months after surgery.

Dermatofibroma simulating seborrheic keratosis dermoscopically

Dermatofibroma is a frequent benign tumor of easy clinical diagnosis in most cases, but that can mimic other dermatoses. Dermoscopy may help to define the diagnosis and its classical pattern is a central white area, similar to a scar, surrounded by a discrete pigment network. However, dermoscopic findings are not always typical. We describe here a case of dermatofibroma exhibiting ridges, furrows and pseudocomedos, a pattern which is typical of seborrheic keratosis, in dermoscopy.

Dermatomyofibroma

We report a case of dermatomyofibroma that, to our knowledge, is the second case reported in Brazil. About 100 cases have been reported worldwide. Dermatomyofibroma represents a rare, benign mesenchymal neoplasm of fibroblastic/myofibroblastic differentiation, with prolonged evolution and little or no symptoms. It most commonly occurs in young women and male children. Dermatomyofibroma can be easily confused with other clinical entities, which could lead to unnecessary treatments. Therefore, it is important that dermatologists and pediatricians suspect and start to consider this hypothesis in their diagnostic exercises.

[Cutaneous sarcomas: update on selected fibrohistiocytic and myofibroblastic tumors]

BACKGROUND

Malignant fibrohistiocytic tumors are a heterogeneous group of mesenchymal neoplasms that may occur in the skin and subcutaneous tissues.

DIAGNOSIS

Diagnosis of these tumors may be difficult, as they are rare, and a wide morphological diversity of types and subtypes has been described. In this update, relevant aspects of selected entities like dermatofibrosarcoma protuberans, desmoid tumor, atypical fibroxanthoma, pleomorphic dermal sarcoma, and myxofibrosarcoma are discussed according to the WHO classification of 2013. The typical clinical feature of these tumors is their mostly asymptomatic appearance. For diagnosis, the histologic workup is therefore the key feature; herein immunohistochemistry as well as molecular diagnostics become increasingly important.

THERAPY

The primary treatment for locally resectable tumors is complete surgical removal; chemotherapy, radiation, and targeted therapies with kinase inhibitors are available for inoperable and metastatic disease.

[Fibrous papules of the face: a retrospective anatomoclinical study of 283 cases]

BACKGROUND

Fibrous papules of the face are frequent benign lesions seen in the nasal and perinasal region. Their clinical aspect is indistinct and the histological signs are sometimes mild or possibly misleading in the case of atypical forms. We carried out a retrospective study of 283 fibrous papules diagnosed at our histology laboratory. The goal of this study was to characterize this type of frequent but occasionally unrecognized lesion.

PATIENTS AND METHODS

We performed a retrospective study of fibrous papules of the face diagnosed in the dermatopathology laboratory of our dermatology centre between January 2002 and December 2011. The study concerned the clinical information noted in the examination request and the morphological abnormalities seen at optical microscopy. An immunohistological study of factor XIIIa was performed in selected cases.

RESULTS

The fibrous papules of the face came from 129 men and 154 women aged between 18 and 90 years (mean: 46 years). Two hundred and thirty-seven (83.7%) lesions were taken from the nasal region and none were taken from anywhere other than the face. The clinically mentioned diagnoses varied. A diagnosis of fibrous papule of the face was stated in 42% of cases, and the main differential diagnoses were nevus (stated in 34% of cases) and basal cell carcinoma (stated in 14% of cases). The fibrous papules were classic in 85.5% of cases. We observed 6 variants of fibrous papule: hypercellular, inflammatory, pleomorphic, pigmented, clear-cell and granular-cell types. Immunohistochemistry of factor XIIIa was positive in all cases except clear-cell fibrous papules.

DISCUSSION

This study shows that despite their frequency, these lesions often go unrecognized, since the hypothesis of a fibrous papule of the face was mentioned in fewer than 50% of cases at the time of biopsy. Diagnosis is often made by the histopathologist, who may be misled by some rare types. The principal differential diagnoses are nevus and basal cell carcinoma, thus warranting methodical histological analysis of all pieces.

Phenotypic characterization of human keratinocytes in coculture reveals differential effects of fibroblasts from benign fibrous histiocytoma (dermatofibroma) as compared to cells from its malignant form and to normal fibroblasts

BACKGROUND

Benign and malignant fibrous histiocytoma present with a considerable difference concerning cellular organization in their vicinity.

OBJECTIVE

Normally appearing epithelium covers the malignant form in contrast to hyperplastic epidermis for benign tumors. It is an open question as to whether the tumor-associated fibroblasts are capable to affect phenotypic features of normal keratinocytes, prompting this comparative analysis.

METHODS

Fibroblasts were isolated from benign and malignant fibrous histiocytomas, respectively, and also from normal dermis. The resulting cell populations were thoroughly characterized immunocytochemically using a large panel of antibodies. The three fibroblast preparations were cocultured with normal interfollicular keratinocytes. Their phenotype was characterized for distinct properties including differentiation and proliferation.

RESULTS

Fibroblasts prepared from both tumor types were phenotypically practically identical with normal dermal fibroblasts. Their activities on keratinocytes were different. Cells prepared from benign fibrous histiocytoma were capable to effect strong expression of keratin 19 and production of a galectin-1-rich extracellular matrix. Fibroblasts isolated from malignant fibrous histiocytoma led to a phenotype very similar to that when keratinocytes were cocultured with normal dermal fibroblasts.

CONCLUSION

Fibroblasts prepared from benign fibrous histiocytoma were biologically active on keratinocytes in a particular manner. Our results on fibroblast activity are suggested to be relevant for morphologic differences observed in vivo between normal epidermis and epidermis adjacent to the studied tumor types.

[Skin tumours of the facial area]

Almost the complete spectrum of skin tumours can occur within the facial area, ranging from benign tumours of infancy to typical malignancies of old age. This spectrum is quiet heterogeneous and comprises every cell type within the skin as a possible origin for tumour growth. Among these are cells derived from the epidermis; adnexal structures; connective, fatty, and vascular tissue; muscle; nerves; melanocytes; and skin-infiltrating inflammatory cells. Due to this diversity, a correct assessment of the clinical findings compared with a histopathologic appraisal in cases of uncertainty is mandatory in order to recommend appropriate therapy. The present overview aims to summarise the basics of the most frequent and most important skin tumours occurring on the face.