Superficial acral fibromyxoma: a clinicopathological analysis of 32 tumors including 4 in the heel

Surgery for benign nail tumor

The vast majority of tumors in the nail apparatus have a different clinical presentation and course from their equivalents on the skin. Some, such as onychomatricoma and onychopapilloma, are unique to the nail and others, such as superficial acral fibromyxoma, have a tropism for the nail apparatus. As a rule, benign lesions respect the general architecture of the nail apparatus, whereas malignant tumors are destructive. Treatment is always surgical and good knowledge of the anatomy and the procedures is mandatory in order not to induce postoperative nail dystrophy.

Superficial Acral Fibromyxoma: A Report of Two Cases with CD68 Expression

Superficial Acral fibroma (SAF), also known as osteofibroma, is a rare fibromatous tumor primarily involving superficial soft tissues. Clinically, SAF typically manifests as a slow-growing, solitary, well-defined nodule or mass. Although these lesions are generally asymptomatic, some cases may present with associated pain, often linked to a history of trauma. SAF lesions commonly exhibit hemispherical, polypoid, or warty growths, with occasional occurrences of ulceration and bleeding.The majority of SAFs express CD34 and CD99, but in the two cases we report, there was diffuse expression of CD34 and focal positive expression of CD68. CD68 positivity suggests a propensity for tumor cells to metastasize to secondary sites. Notably, previously reported cases of single SAF did not display positive CD68 expression, indicating a potential association with other aggressive tumors. However, the current clinical and pathological manifestations do not clarify the diagnosis of additional malignant tumors. Consequently, regular postoperative monitoring of the patient from the aforementioned two cases is essential to detect the presence of other malignant tumors. The significance of CD68-positive expression in this case lies in its potential association with such tumors.

Superficial acral fibromyxoma: a case of missed diagnosis

Superficial acral fibromyxoma (SAFM) is a rare, benign, slow-growing fibroblastic tumour of the soft tissue that is part of the group of myxoid soft-tissue neoplasms. It is a rare entity and usually occurs in the acral regions. We report the case of a 64-year-old man who presented to the emergency room for a lesion expected to have occurred as a result of an ingrown toenail. Because this patient had a history of repeated recurrences despite multiple surgical wedge excisions, we performed a complete surgical excision, and the pathological analysis confirmed the suspected diagnosis of SAFM. There was no recurrence at the 6-month follow-up. This case highlights the fact that this tumour is still misunderstood and underrecognized by surgeons and this often leads to delayed diagnosis. Although it is a rare entity, clinicians should be aware of this tumour in cases of recurring ingrown toenails.

Rare Variants of Dermatofibrosarcoma Protuberans: Clinical, Histologic, and Molecular Features and Diagnostic Pitfalls

Dermatofibrosarcoma protuberans (DFSP) is a dermal malignant mesenchymal tumor. Most variants are associated with a high risk of local recurrence and a low risk of metastasis. The classic histomorphology of this tumor is made up of uniform, spindle-shaped cells, arranged in a storiform pattern. Tumor cells characteristically infiltrate the underlying subcutis in a honeycomb pattern. Less common variants of DFSP have been identified: myxoid, pigmented, myoid, granular cell, sclerosing, atrophic, and fibrosarcomatous. Only the fibrosarcomatous variant has been shown to differ significantly from classic DFSP in terms of clinical outcome; fibrosarcomatous DFSP has been shown to be associated with a greater risk of local recurrence and metastatic potential than classic DFSP. However, the other variants may pose diagnostic difficulty as they resemble other types of spindle cell neoplasms, especially in small biopsy specimens. This article reviews the clinical, histologic, and molecular features of DFSP variants, as well as possible pitfalls in their diagnosis and how to resolve them.

Acral fibromyxoma: a rare plantar nodule

Acral fibromyxomas are benign tumours ranging in size between 0.6 and 5 cm, commonly found around the nailbed. The often asymptomatic presentation of acral fibromyxomas means that there is often a delay in their diagnosis and subsequent treatment. The objective of this paper is to present the unique case of a fibromyxoma present in the acral region, as well as a review of the literature.

Superficial Acral Fibromyxoma: Clinicopathologic Analysis of Five Cases

Superficial acral fibromyxoma is a relatively rare benign slow-growing soft-tissue tumor, first described by Fetsch's group [Hum Pathol. 2001;32:704-14]. Since then, around three hundred publications have concerned this relatively new entity. The tumor involves peri- and subungual regions of fingers and toes in middle-aged adults with slight male predominance. This acral fibrous tumor is poorly known, and in certain cases, histology results may suggest myxoid dermatofibrosarcoma, which carries a completely different prognosis. In this article, we discuss the clinicopathologic features of this acral fibrous tumor through the report of 5 cases including 1 particular clinical presentation that revealed as a retronychia in a young woman.

Nail Tumors

This article describes nail tumors and their clinical features, biologic behavior, and treatment. Tumors included are onychopapilloma, onychomatricoma, periungual fibromas/fibrokeratomas, glomus tumors, subungual exostosis, myxoid cysts, and squamous cell carcinoma.

EWSR1-SMAD3 rearranged fibroblastic tumor: Case series and review

We report the largest series to date (N = 6) of EWSR1-SMAD3 rearranged fibroblastic tumor. Initially described in 2018, the tumor features a marked female predominance (F:M, 5:1, mean age 44-years, median age 45.5 years; range 27-57), with most cases (5/6, 83%) arising in acral locations (4 on foot/toe, 1 on hand). One case presented on the lower extremity. The lesions presented as nodules and were composed of short, variably cellular, intersecting fascicles of uniform spindled cells in a collagenous to myxoid stroma. In four cases, the tumor abutted the epidermis without a grenz zone. In one case, there was an abrupt transition to a central, acellular hyalinized area. Two other cases had admixed smaller collagenous areas, reminiscent of collagen rosettes. One had a concentric arrangement of tumor cells around blood vessels. Mitotic activity was low (<1/10 HPFs). All were positive for ERG by immunohistochemistry and negative for CD34 (6/6). An EWSR1-SMAD3 fusion was identified in three cases tested by next-generation sequencing (3/3). Rearrangement of EWSR1 by fluorescence in situ hybridization was showed in 1/1 case. Our series reaffirms prior findings and expands the known histopathologic spectrum of this emerging entity.

Superficial Acral Fibromyxoma, Appearing as Retronychia: A Rare Clinical Entity

We report a case of a subungual superficial acral fibromyxoma (SAFM) in a 37-year-old male patient who presented with a persistent chronic proximal paronychia of the big toenail of the right leg. Our clinical diagnosis was retronychia, an often misinterpreted condition, which must be suspected in cases of persistent paronychia, especially in the setting of trauma. The nail plate avulsion revealed a subungual tumor, which was surgically excised. Histopathology in combination with immunohistochemistry revealed features suggestive of SAFM. The follow-up examination of the patient showed no recurrence 9 months after the surgery.

Cellular Digital Fibroma: A Comprehensive Review of a CD34-Positive Acral Lesion of the Distal Fingers and Toes

Cellular digital fibroma is a benign fibrous lesion that typically occurred on either a finger or a toe. Cellular digital fibroma was introduced as a distinctive cluster of differentiation 34 (CD34)-positive lesion in July 2005. Cellular digital fibroma has been described in 20 patients: 12 men and 8 women. The patients ranged in age from 27 to 83 years old (median, 52 years old) at diagnosis. The tumor had been present from 2 months to 2 years (median, 11 months) prior to seeking medical attention. The cellular digital fibroma was usually slowly growing and asymptomatic; there has been no prior history of trauma at the tumor site. The lesion typically presented as either an erythematous or a flesh-colored, solitary papule of 5 mm or smaller. It frequently occurred on either the dorsal, lateral or ventral side of a digit. Yet, some of the lesions were located on the nail fold of the digit. Cellular digital fibroma shows a prominent cellular proliferation of spindle-shaped fibroblasts, without any atypia or mitoses, that extends from the papillary into the upper reticular dermis; diffuse and strongly positive CD34 staining is present throughout the entire tumor. There is no erosion by the tumor of the bony phalanx. Other acral tumors, such as superficial acral fibromyxoma (which also has diffuse strongly positive CD34 staining) and acquired digital fibrokeratoma (which is either CD34-negative or only focal CD34 positive), are in the clinical and pathologic differential diagnosis of cellular digital fibroma. Conservative complete excision is the treatment of cellular digital fibroma; however, even for tumors that have only been partially removed during biopsy, recurrence has not been observed. In conclusion, cellular digital fibroma is a unique CD34-positive acral lesion of the distal fingers and toes whose diagnosis requires correlation of the clinical morphology and the pathologic features of the tumor.

Acral fibromyxoma with loss of Rb1 by immunohistochemistry and fluorescence in situ hybridization: A diagnostically exploitable marker

Acral fibromyxoma (AF) is a slow growing benign soft tissue tumor with predilection to subungal and periungal region of the hands or feet. CD34 is consistently expressed whereas very recently loss of Rb1 expression was described as a possible driver molecular event for this entity. Herein we present two additional cases of AF with loss of Rb1 expression by IHC and subsequent confirmation of loss of the RB1 gene locus by fluorescence in situ hybridization (FISH). We hope to raise awareness in dermatopathology community of this new discovery, which can be diagnostically exploitable for this distinct and probably underreported neoplasm.

Superficial Acral Fibromyxoma: Literature Review

Superficial acral fibromyxoma is a benign and rare tumor of the soft tissues. It usually manifests itself through a painless mass of slow growth that affects mainly males in the fifth decade of life. It usually affects the distal region, with a polypoid or dome-shaped appearance. The histological appearance is of a dermal mass without capsule, with spindle-shaped fibroblasts in a storiform or fasciculated pattern in the myxocollagenous stroma. The immunohistochemical evaluation of superficial acral fibromyxoma is usually positive for CD34 and CD99, with variable positivity for epithelial membrane antigen. The treatment consists of complete excision of the tumor mass.

A review of the current literature on superficial acral fibromyxoma was performed, with an emphasis on the number of cases reported, location, diagnostic methods, histological characteristics, differential diagnoses and treatment.

A total of 314 reported cases of superficial acral fibromyxoma with variable locations were found in the current literature, mainly in the toes (45.8%) and fingers (39.1%). It has a slightly superior incidence in men (61%) and enormous variability in the age range of occurrence.

Superficial acral fibromyxoma is a single soft-tissue tumor that should enter the differential diagnosis of periungual and subungual acral lesions; the treatment consists of simple excision. More studies are needed to better understand this pathology, which was first described in 2001.

Superficial acral fibromyxoma in the heel with new vascular features on dermoscopy

Superficial acral fibromyxoma (SAFM) is an uncommon mesenchymal soft tissue tumor with a predilection for the acral extremites and nail bed involvement. SAFM is diagnosed with clinicopathological and immunohistochemical examination. Awareness of this rare tumor is important because of amounts of benign and malignant neoplasms. We report a case of SAFM in a rare localization in the heel with a new finding on dermoscopy.

Superficial Acral Fibromyxoma: A Rare Soft Tissue Tumor

Superficial acral fibromyxoma is a rare clinical entity, first described in 2001. It is a soft tissue tumor with a predilection for the fingers and toes. Since it was described, few cases have been reported. We present a case of an 88-year-old male with a history of a slow-growing lump in his left great toe after local trauma. The patient underwent surgical excision, and pathologic analysis revealed the diagnosis of superficial acral fibromyxoma. Although an unusual diagnosis, surgeons should be aware of this myxoid tumor, which requires complete surgical excision and short-term follow-up to detect recurrence.

Nail neoplasms

Nail neoplasms include all tumors occurring in the nail or periungual apparatus tissue. While some nail tumors can be similar to tumors located on the skin, others are unique. Both benign and malignant lesions can affect the nail apparatus. In particular, early malignant tumors like melanoma and squamous cell carcinoma can present similarly to onychomycosis or benign melanonychia and frequently missed by clinicians. Therefore, physicians should be aware of nail structures and the characteristics of nail tumors. Our review covers the normal nail structure and the most common nail tumors from benign to malignant.

CD34 negative superficial acral fibromyxoma: A rare case report

Superficial acral fibromyxoma (SAF) is a slow growing soft tissue tumor that mainly appears in the acral areas. Here, we report a case of a SAF with distinctive immunophenotype charachteristics. An 18-year-old female was referred to our clinic with the complaint of painless subungual nodule of great toe for a few months. The diagnosis of SAF was made according to histopathology and immunohistochemical (IHC) study, however, the IHC assessment showed positive staining with vimentin, focal reaction with smooth muscle actin, negative reaction with CD34, and positive staining pattern with CD99. These IHC findings are unusual for SAF. This reported case of SAF supports the fact that, although CD34 expression is characteristic for SAF, it is not always present.

Pedal Presentation of Superficial Acral FibromyxomaA Case Report

Superficial acral fibromyxoma is a benign and slow-growing solitary soft-tissue neoplasm. Since being described in 2001, more than 100 cases of superficial acral fibromyxoma on the foot have been reported worldwide, none of which have been reported in the podiatric medical literature. Only nine cases of superficial acral fibromyxoma have been reported with presentation on the plantar heel. We report an unusual case of a 47-year-old Jamaican woman with a painful, erythematous nodule on her right heel that was diagnosed as superficial acral fibromyxoma.

Superficial Acral Fibromyxoma of the Toe: Unusual Location of the Mixoid Variant

Superficial acral fibromyxoma (SAFM) is a rare soft tissue tumor that frequently involves the periungual and subungual regions of acral surfaces. Macroscopically, it appears as a flesh-colored dome-shaped solitary mass; microscopically, it consists of a moderately cellular proliferation of spindle-shaped fibroblast-like cells embedded in a myxocollagenous stroma and arranged in a loose storiform and focally fascicular pattern. The tumor cells are immunoreactive for CD34, epithelial membrane antigen, CD99, and CD10. In this study, we describe a case of SAFM on the fourth toe with predominantly myxoid stroma. Our case, in contrast of those reported in the literature, showed an unusual location for the myxoid variant. SAFM is often not recognized; it may resemble some benign and malignant mesenchymal neoplasm. The gold standard treatment is surgery. The tumor was completely excised, and no recurrence was evident at 1-year follow-up. Awareness of this entity facilitates its diagnosis and management, avoiding unwarranted concerns and additional procedures for the patient.

Superficial acral fibromyxoma: clinicopathological, immunohistochemical, and molecular study of 11 cases highlighting frequent Rb1 loss/deletions

Superficial acral fibromyxoma (SAF) is an uncommon benign dermal mesenchymal lesion of adults with predilection for acral sites, in particular the nail region. To date, less than 300 cases have been reported. SAFs consistently express CD34, but other diagnostic markers or specific genetic alterations have not been established yet. We describe 11 SAFs occurring in 7 men and 4 women aged 37 to 86years (median, 48 years). Mean size was 6mm (range, 4-20mm). Affected sites were fingers (n=5), toes (n=3), heel (n=1), calf (n=1), and unspecified digit (n=1). None of 10 patients with available follow-up (2-60months; median, 24months) developed recurrence. Histology showed relatively hypocellular vaguely lobulated nodules composed of bland-looking spindled or stellate fibroblast-like cells arranged into storiform or loose fascicles within a variably myxoid, fibromyxoid, or collagenous vascularized stroma. Immunohistochemistry showed expression of CD34 (9/10) and focal weak reactivity for epithelial membrane antigen (2/11). None of the lesions expressed protein S100 (0/11), MUC4 (0/11), or STAT6 (0/11). Loss of Rb1 immunoexpression was observed in 9 (90%) of 10 cases. All 7 cases with successful RB1 fluorescence in situ hybridization testing showed RB1 gene deletions, which was variably associated with co-loss of the corresponding 13q12 signal (monosomy at the 13q region). To our knowledge, this is the first study investigating the expression status of the tumor suppressor Rb1 in SAF by immunohistochemistry and fluorescence in situ hybridization. Our results showed frequent Rb1 deficiency as a possible driver molecular event in SAF (seen in 90% of cases) indicating relationship of SAF to the RB1-deleted tumor family.

Superficial Acral Fibromyxoma: A Rare Entity - A Case Report

Superficial acral fibromyxoma (SAF) is a rare lesion initially described by Fetsch as a tumour with histological and immunohistochemical features located at acral sites. It is a benign slow-growing soft tissue lesion occurring in males. Patients generally look for late medical help as it is generally painless. The lesion consists of spindled and stellate-shaped cells in the myxocollagenous stroma with immunohistochemical positivity for CD34, CD99 and vimentin. Treatment is surgical excision with regular follow-up. Here we present a case of a superficial acral fibromyxoma of the left index finger which radiologically showed features of vascular anomaly on MRI. The lesion was surgically excised and histopathology revealed features suggestive of superficial fibromyxoma with positive immunohistochemistry for CD34 and negative for S-100.

Myxoid Neoplasms

Myxoid tumors of soft tissue constitute a heterogeneous group of neoplasms characterized by the presence of a myxoid stromal matrix, which appears on H&E as an amorphous material and may be confused with edema. Superficial myxoid lesions in general are benign and deep ones are malignant. Grossly, they have a variable gelatinous quality and overlapping histologic features that may present diagnostic difficulties for pathologists. Most are sporadic neoplasms, with only a small percentage arising in patients with hereditary disorders. Discussed are key features of classic myxoid lesions, histologic features, characteristic clinical presentations, immunohistochemical patterns, cytogenetic analysis, and differential diagnosis.

Superficial acral fibromyxoma

Superficial acral fibromyxoma (SAF), also known as digital fibromyxoma, is a rare soft tissue tumor with a predilection for acral surfaces. Superficial acral fibromyxoma classically presents as a pink to flesh-colored nodule located on the subungual or periungual region of the hands or feet. It is typically slow-growing and asymptomatic, which, coupled with its nonspecific clinical appearance, presents a diagnostic dilemma to the dermatologist. As these features overlap with those of a multitude of differential diagnoses, it is imperative to have a good understanding of the characteristics on which the diagnosis of SAF is based. Superficial acral fibromyxoma was initially described in 2001, since when several case reports and literature reviews have contributed to our current understanding of these tumors. In this article, we will review the history, clinical features, diagnosis, and management of SAF. It is our hope that this systematic approach will help to facilitate the recognition and management of this distinct dermatologic entity.

Superficial Acral Fibromyxoma involving the nail's apparatus. Case report and literature review

Superficial Acral Fibromyxoma is a rare tumor of soft tissues. It is a relatively new entity described in 2001 by Fetsch et al. It probably represents a fibrohistiocytic tumor with less than 170 described cases. We bring a new case of SAF on the 5th toe of the right foot, in a 43-year-old woman. After surgical excision with safety margins which included the nail apparatus, it has not recurred (22 months of follow up). We carried out a review of the location of all SAF published up to the present day.

[Superficial acral fibromyxoma in a sub-matricial location: An unusual variant]

BACKGROUND

Superficial acral fibromyxoma (SAFM) is a benign soft tissue tumor located in the acral areas, particularly the peri- and sub-ungueal areas. Sub-matricial localisations have not been reported to date.

PATIENTS AND METHODS

We report herein the clinical and pathological presentation of three cases of SAFM located solely under the matrix. The patients presented with pseudo-clubbing, onychogryphosis or triangular macrolunula. The histopathological appearance was characteristic.

DISCUSSION

SAFM is a slow-growing, skin-colored, firm nodule, located chiefly on the digits or the toes, and especially in the nail area. It may or may not be painful. Microscopically, it presents as a relatively well-circumscribed but unencapsulated dermal tumor, composed of spindle shaped cells integrated in a myxocollagenic matrix, sometimes invading the subcutis. Tumor cells diffusely express CD34. A conservative surgical approach is recommended. Both clinicians and pathologists should be aware of this entity in order to avoid misdiagnosis, which can lead to unwarranted mutilating surgery.

CONCLUSION

Sub-matricial localisation of SAFM is extremely rare and may present as pseudo-clubbing, isolated onychogryphosis or a triangular macrolunula. A conservative surgical approach should be recommended.

Acquired reactive digital fibroma: a clinicopathologic report of 5 cases of a new entity

BACKGROUND

Fibroblastic proliferations in the dermis comprise a heterogeneous group of disorders that can pose diagnostic challenges.

OBJECTIVE

We sought to study the clinicopathologic features of this tumor.

METHODS

We reviewed the clinicopathologic features of 5 unusual mesenchymal tumors of the digits that, to our knowledge, correspond to an entity not previously described.

RESULTS

The patients were 5 men. All cases were located in the digits and were associated with history of trauma. Histopathologically, the neoplasms were located mainly in the reticular dermis. The tumors consisted of solitary nodules composed of fascicles of benign-appearing spindle cells devoid of cytologic atypia. The spindle cells formed short fascicles arranged in a haphazard manner. On immunohistochemistry, the tumor cells expressed vimentin and in 2 cases, CD34. The tumor cells were negative for smooth muscle actin (SMA), desmin, h-caldesmon, epithelial membrane antigen (EMA), S100, CD68, CD99, and beta-catenin.

LIMITATIONS

Only 5 cases were studied.

CONCLUSIONS

Awareness of this entity is of importance to avoid misdiagnosis with other conditions. Based on the immunohistochemical pattern, we believe that these tumors are fibroblastic in origin. The peculiar gross appearance and location of the lesions is clinically quite distinctive and may lead to confusion with other neoplastic and reactive processes.

Superficial Acral Fibromyxoma of the Thumb: A Case Report

The authors report a case of superficial acral fibromyxioma (SAF) in a 74-year-old male who presented with a painless mass in a periungual dorsoradial region of the right thumb. It is a rare benign neoplasm, which was recently described, that arouse on the skin and subcutaneous tissue of the hands and feet, especially in the proximity to the ungual region of male adults. Surgical treatment was performed with the excision in blocks of the margins of the lesion and fragmentation of the nail and nail matrix, according to the literature recommendation. Although there may be local recurrence in 22% of the cases, the patient presents no symptoms, deformities or functional limitations. In addition, there was no sign of tumor recurrence 18 months after the surgery. We are not aware of a similar case report in the Brazilian literature.

Benign subungual tumors

A variety of benign and malignant processes may affect the subungual region; however, most are relatively rare lesions. We present a review of the current literature regarding benign tumors affecting the subungual region.

Superficial Acral Fibromyxoma: An Overview

Superficial acral fibromyxoma is a rare, slow-growing soft tissue tumor, which is commonly located in the periungual and subungual regions of the fingers and toes in adults. To date, fewer than 50 cases have been reported worldwide. Microscopic examination reveals a moderately circumscribed, nonencapsulated tumor situated in the dermis, which may also extend into the subcutis. The neoplasm consists of a moderately cellular proliferation of stellate and spindle-shaped fibroblast-like cells embedded in a myxocollagenous stroma. Mast cells are easily identified throughout this lesion. Multinucleated stromal cells may also be present, but nuclear atypia and mitotic figures are rare. The tumor shows immunoreactivity for CD34, epithelial membrane antigen, CD99, and less frequently, CD10. Superficial acral fibromyxoma has a benign behavior but may persist or recur if inadequately excised. Therefore, complete excision and close follow-up are advised.