An unknown mass: the differential diagnosis of digit tumors

A Rare Case of Plexiform Schwannoma of the Little Finger and Its Management: A Case Report

Schwannomas are tumors of the Schwann cells found in the myelin sheath. They cause 5% of all benign soft-tissue cancers, occur equally in males and females, and occur later in life. Since they remain asymptomatic, diagnosing and treating them becomes challenging; current guidelines recommend imaging followed by excision. Here, we present a case of a 19-year-old male who presents in an outpatient setting with a history of painless swelling of the fifth digit for the past four years. Past medical history and physicals are unremarkable. Microscopic findings from fine-needle aspiration cytology (FNAC) confirmed the schwannoma diagnosis, showing loosely arranged spindle cells with elongated nuclei with pointed ends dispersed within the myxoid stroma.

Diffuse Type Neurofibroma of the Forearm

Nerve sheath tumors comprise 5% of soft tissue masses of the upper limb in adults. Neurofibromas are divided into three types: localized, diffuse, and plexi- form. The diffuse type is rare and is typically found in the head and neck region. We present a rare case of diffuse type neurofibroma found in the forearm, presented to our clinic as a slowly enlarging mass of the left forearm of 3 years duration. The lesion was suspicious in the magnetic resonance imaging, and biopsy revealed diffuse type neurofibroma. We opted for total excision of the lesion that was found to be not possible due to involvement of the major nerves. The final pathology report showed no malignancy. Nerve tumors of the upper limb can be either benign or malignant. Neurofibroma associated with neurofibromatosis has malignant potential. The diffuse type is rare, and it most commonly occurs in the head and neck region. It has a low malignant transformation rate. Magnetic resonance imaging is the diagnostic modality of choice; however, it can be inconclusive. Biopsy should be taken to confirm the diagnosis and plan for management. Our case was managed by near total excision in order to preserve the major forearm nerves because of high clinical suspicion.

Clinical characteristics and differences among 802 acral tumors by anatomical sites

BACKGROUND

Acral skin tumors are common, but there are few literature reviews regarding their incidence.

OBJECTIVES

To investigate the clinical characteristics and differences in incidence of benign and malignant acral tumors by anatomical site.

METHODS

A retrospective review of 802 patients with acral skin tumors confirmed by skin biopsy between January 2010 and December 2019 was conducted. Age, sex, duration, symptoms, and sites were obtained from medical records and photographs.

RESULTS

The mean age of onset was 43.8 years with a male-to-female ratio of 1:1.41, and the mean duration was 68.8 months. Most were asymptomatic (66.7%). In total, 802 acral tumors were identified: 512 (63.8%) were benign and 290 (36.2%) were malignant. The most common benign tumors were benign melanocytic lesions (n = 239), and the most common malignant tumors were melanoma (n = 234). The most common site was the sole (n = 408). Benign melanocytic lesions, melanoma, and epidermal cyst were more frequent on the foot, and pyogenic granuloma, glomus tumor, hemangioma, and mucous cyst were more frequent on the hand. Glomus tumor, fibroma, mucous cyst, and osteoma were more frequent on the nail portion, and benign melanocytic lesions and epidermal cyst were more frequent on the non-nail portion.

CONCLUSIONS

This study reports the incidence of various benign and malignant acral tumors according to site, and we believe the results will be helpful in making a diagnosis in the clinic.

Acquired Periungual Fibrokeratoma Looks like a Supernumerary Digit: An Uncommon Soft Tissue Tumor

Acquired digital fibrokeratoma is an uncommon, benign fibrous tumor that usually occurs in adults as a solitary lesion with a typical size of less than 1 cm. We present a case with periungual growth and nail plate deformity. The growth was completely excised after raising the epinychial flap and the fold was reconstructed. The histological results confirmed the digital fibrokeratoma. The rarity of digital fibrokeratoma and its unique morphological appearance of the tumor makes it interesting. Acquired periungual fibrokeratoma, an uncommon benign fibrous tumor of an unknown etiology, typically found at the distal end of the digits, may present with nail plate deformation due to chronic pressure, and in order not to damage the matrix, the tumor should be excised carefully, which can cause permanent nail dystrophy. In addition, we emphasize the importance of ruling out other causes of abnormal growths and of considering fibrokeratoma during differential diagnoses.

Nerve Tumors of the Upper Extremity

Nerve sheath tumors of the upper extremity are among the common neoplastic pathologies encountered by hand surgeons. A majority of these tumors are benign schwannomas or neurofibromas and may be associated with neurofibromatosis. Clinical signs of malignant transformation include new onset of pain and rapid growth. Imaging characteristics, such as standardized uptake value greater than 4.0 on PET scan, may aid in the diagnosis of a malignant tumor. Surgical excision, often with intrafascicular dissection with nerve preservation, is recommended treatment of benign lesions. Wide surgical excision is recommended for malignant lesions.

Initial Misidentification of Thumb Poroma by Shave Biopsy

Poromas are benign adnexal neoplasms originating from the intraepidermal portion of sweat gland ducts. With the possibility of malignant transformation, accurate clinical diagnosis and treatment are crucial. Numerous reports of hand poroma lesions have been reported. We present an unusual case of a distal thumb poroma originally identified as a squamous cell lesion in a shave biopsy and eventually accurately identified after excisional biopsy. This report highlights the limitations of shave biopsy associated with soft tissue hand lesions and the need to consider poroma when evaluating a soft tissue lesion of the hand.

Acquired digital fibrokeratoma: review of its clinical and dermoscopic features and differential diagnosis

Acquired digital fibrokeratoma (ADFK) is a rare, benign, fibrous tumor that most often occurs on fingers. It may resemble a rudimentary supernumerary digit and is often misdiagnosed as another common benign condition, such as common wart. It is typically asymptomatic and occurs as a solitary nodule less than 1 cm in diameter. Oftentimes ADFK shares clinical and/or histologic resemblance with other benign and malignant cutaneous conditions so it is crucial that careful examination is undertaken. In this article, we will discuss the clinical presentation, epidemiology, etiology, dermoscopic and histologic findings, management, and differential diagnoses for ADFK, with the hope that this review will facilitate timely diagnosis and management for this distinct condition.

CT and MRI of superficial solid tumors

Superficial solid masses are common conditions in clinical practice, however, some of which can be easily diagnosed and others would be difficult. Although imaging of superficial masses is not always characteristic, it would be helpful to give a definitive diagnosis or narrow a differential diagnosis. Crossing-section imaging can depicture the masses directly, find some pathognomonic signs and demonstrate their relationship with adjacent structures, which can provide decision support for clinician's reference. Computed tomography (CT) can be used to detect calcifications and bone erosion which could not be seen on radiographs. Magnetic resonance imaging (MRI) is the preferred way for evaluating soft tissue lesions and provides information on hemorrhage, necrosis, edema, cystic and myxoid degeneration, and fibrosis. Other advantages of MRI are its superior soft tissue resolution and any profile imaging, which can aid the assessment of extension and adjacent infiltration. Positron emission tomography (PET)/CT and PET/MRI have been increasingly used in bone and soft tissue sarcomas and provides advantages in the initial tumor staging, tumor grading, therapy assessment, and recurrence detection. Therefore, imaging examination can play an important role in treatment decision making for superficial solid tumors. Here we review the important conditions presenting as superficial mass and show the imaging of typical cases diagnosed in our hospital.

Unusual size, topography, and surgical resolution of an acquired fibrokeratoma

Acquired fibrokeratoma is a rare benign skin tumor that usually manifests as a slow-growing solitary nodular lesion of the digits. We report a case of plantar acquired fibrokeratoma evidencing its atypical size and topography, in addition to the treatment with simple surgical excision followed by healing by second intention. Nondigital fibrokeratomas may occur in 18% of cases and rarely affect the palmoplantar region. These lesions are usually asymptomatic and show ≥ 3cm in size at the time of diagnosis due to delayed diagnosis. Complete surgical excision is the treatment of choice, which is usually curative. In general, primary closure is chosen; however healing by second intention becomes an option in regions of difficult approach.

MILKER’S NODULE. A PERPLEXING FARMYARD INFECTION AND THREAT TO THE IMMUNOCOMPROMISED

Milker’s nodules, also called paravaccinia, is a DNA virus transmitted from infected cows to humans. It results from contact with cattle, cattle byproducts, or fomites. Classified as an occupational disorder, those at risk of exposure include farmers, butchers, and agricultural tourists. The viral infection begins 5—15 days after inoculation as an erythematous-purple, round nodule with a clear depressed center, and a surrounding erythematous ring. While familiar to those in farming communities, the presence of the nodule may be concerning to others, particularly the immunosuppressed. Milker’s nodules are selflimited in immunocompetent individuals and heal without scarring within 8 weeks. Another member of the Parapoxvirus genus, the orf virus, is also transmitted from animals to humans by direct-contact. While complications are rare, hematopoietic stem cell transplant recipients are at risk of graft-versus-host disease, as the parapoxvirus may trigger these complications in immunocompromised individuals. In addition, paravaccinia may serve as the antigen source for the development of erythema multiforme. The unique structure and replication process of viruses in the Poxvirus family, while includes the Parapoxvirus genus, have been a focus for treatment of infections and cancer. Manipulation of these viruses has demonstrated promising therapeutic possibilities as vectors for vaccines and oncologic therapy.