[Superficial acral fibromyxoma: three cases]

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: 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.

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.

Fibromyxoma of the Orbit

Fibromyxomas are rare tumors that are not commonly seen in the orbit. The authors present a case of orbital fibromyxoma. A 42-year-old male presented with proptosis of the right eye that began 1 month prior. Magnetic resonance imaging revealed the presence of an orbital mass in the right eye, with low signal intensity on T1-weighted images and heterogeneous high-signal intensity on T2-weighted images. The patient underwent excisional biopsy of the orbital tumor through a Krönlein approach. The tumor originated from the inferior rectus muscle. Histopathologic analysis demonstrated scattered spindle cells, with both fibrous and myxoid stroma. Immunohistochemical staining was positive for Vimentin and negative for S-100 protein and CD34. The tumor was diagnosed as orbital fibromyxoma. The patient showed no evidence of recurrence over 18 months of follow-up after operation.

Fibromyxoma of the Tarsus: A Case Report

A 61-year-old woman presented with a slow-growing mass on the right upper eyelid. The hard, fixed, and nontender mass was apparent on the right upper eyelid. It was immobile, and it seemed to be adhered to the tarsus. Total excision of the mass was performed. A histopathological examination revealed a solid mass with fibrous and myxoid areas with scattered spindle- to stellate-shaped cells in a fibromyxoid matrix. The immunochemistry examination stained positively for CD34 and CD99. Based on these findings, the lesion was diagnosed as a tarsal fibromyxoma. Although rare, a fibromyxoma originating from the tarsus should be considered in the differential diagnosis of solid tarsal lesions.

[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.

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.

Fibromyxoma masquerading as dacryocystitis

Primary tumors of the lacrimal sac are extremely rare and predominantly epithelial in origin. We report a unique case of fibromyxoma of the lacrimal sac in an 86-year-old Caucasian woman who presented with 3 months of lower eyelid edema and 1 week of purulent discharge, epiphora, and acute pain. Examination revealed right lower eyelid erythema/edema and a tender, firm, palpable mass of the right lacrimal sac, which self-expressed a yellow, purulent discharge. On surgical exploration, a firm, rubbery, yellow mass was encountered and excised. Histopathologic analysis identified a nonencapsulated mass composed of loose interlacing fascicles and bundles of spindle-shaped cells with prominent myxoid changes; immunostaining was strongly positive for vimentin, weakly for smooth muscle actin, and negative for S-100 and muscle-specific actin. These findings were consistent with the diagnosis of a fibromyxoma of the lacrimal drainage system. After excision, the patient did well, with resolution of dacryocystitis.