Multilocular Lipoma in the Middle and Index Fingers: A Case Report

Lipomas are the most common type of soft tissue tumor, and 95% of them are benign. While lipomas can present anywhere on the body, 1% of them are found in the fingers. The ultimate goal of management is surgical excision of the mass with preservation of the neurovascular surroundings. Here, we present the case of a 24-year-old, morbidly obese Saudi female patient complaining of large non-tender lumps in the index and middle fingers involving the palmar and dorsal surfaces of the left non-dominant hand. The lumps were associated with paresthesia and tingling sensations. The article aims to report and highlight the satisfactory outcomes after total excision of such lipomas and restoring the function as well as the cosmetic results of the hand.


Introduction
Lipomas are benign fat cell tumors that are primarily found in the head and neck, as well as the shoulder and back [1,2]. Lipomas are considered to be the most common type of soft tissue tumor, and 95% of them are benign [1,3]. While lipomas can present anywhere on the body, 1% of them are found in the fingers [3]. Lipoma of the hand and fingers is considered to be rare; it usually affects the hypothenar and thenar regions [2]. The clinical presentation varies depending on the exact location, but it usually presents as a painless and soft mass felt under the skin [3]. In most cases, lipomas are not treated; they are only observed clinically unless the patient is symptomatic or aiming for cosmetic results [3]. The ultimate goal of management is surgical excision of the mass with preservation of the neurovascular surroundings [1][2][3].

Case Presentation
A 24-year-old, morbidly obese Saudi female patient presented with large non-tender lumps in the index and middle fingers involving the palmar and dorsal surfaces of the left non-dominant hand. The patient reported a history of the initial appearance of the lumps at the age of eight and surgical excision four years before presentation, as well as the history of debulking procedure three years before the surgical excision. The lumps were asymptomatic until they started to be associated with paresthesia and tingling sensations of the involved digits, which affected her daily activities. She does not smoke and is not exposed to second-hand smoke. The rest of her history was unremarkable. The physical examination results were all within the normal limits, except she had a limited range of motion due to the mass in the affected digits. Soft-tissue hemangiomas, vascular malformation lipoma, and lipomas were all considered as differential diagnoses based on the history given.
For further investigations, she underwent Magnetic Resonance Imaging (MRI), which showed an encapsulated multilocular mass in the proximal and distal sections of the index and the middle digits, extending to the palmar and dorsal aspects of the left hand until the carpal bone dorsally and from the first web space to the fourth web space with a volar extension of approximately 3 cm to proximal palmar crease [ Figures 1A, 1B].   The lipoma was found to encompass the zone of incision and was adherent to the extensor mechanism; it was also engulfing the neurovascular bundle. Thus, segmental excision rather than en-bloc resection was preferred due to the engulfment of the structures. Similarly, another incision was made over the middle digit in the radial border, and extensor tendons were repaired, respectively [ Figures 4A-4D].

FIGURE 5: Lipoma excised from the index digit in image A. Lipoma excised from the middle digit in image B.
Intra-operative findings were summarized as two lipomatous tumors excised from the index and middle digits over the ulnar and radial borders, respectively. Histopathology revealed that the specimens consisted of several fragments of fibro-fatty tissue measuring 7.5 x 5.5 x 1 cm, and three ovoid pieces of yellow-tan tissue measuring 5.5 x 4 x 3 cm, and 2.5 x 2 x 1 cm, respectively, for both the left index and left middle digits. After the procedure, the patient was placed in a compressive dressing and volar splint. The patient tolerated the procedure very well and reported satisfactory outcomes with no complications at the one-week followup appointment at an outpatient clinic [ Figures 6A, 6B].

Discussion
Lipomas are the most common form of benign soft tissue tumors with a rare incidence rate in the fingers [1][2][3]. They can be observed or treated with surgical excision, depending on the patient's symptoms and the cosmetic goal [3]. Several articles in the literature have reported on the rarity of lipomas in the hand and digits. Recently, two cases were published reporting on a multilocular lipoma of the left thumb and a giant lipoma of the index extending to the dorsum of the right hand that was excised by performing a modified Bruner incision technique [1][2][3]. The two cases resulted in a successful surgical outcome with good cosmetic results [1][2][3]. Lipomas in the middle finger are rare, and excision is the best way to restore the normal function of the digit. Considering lipoma of the finger as a differential diagnosis and the preoperative use of ultrasound and MRI aid in good surgical outcomes, which is highlighted in the literature [2][3][4][5]. Furthermore, a rare case of a giant lipoma of the hand extending from the thenar to the deep palmar space was reported; it was completely excised, resulting in a good surgical outcome [6]. In terms of rarity, a parosteal lipoma of the proximal phalanx of the hand accounts for less than 0.1% of all primary bone tumors. In one study, a patient with this type of lipoma was treated and managed surgically with no recurrence at the two-year follow-up [7]. The review of different articles shows that surgical excision of such lipomas is considered the preferred method that results in satisfactory outcomes; in most cases, it also restores the function of the digit. Table 1 summarizes previous studies.

Year Authors
Title Aim

Giant lipoma of the third finger of the hand
This case reports a rare location of lipoma of the third finger and repercussion in the decision-making process when other more common similar pathologies with varying prognoses are conceived [2].
Lipoma of the middle finger: A case report and review of literature The case reports a lipoma of the middle finger, and an ultrasound and MRI should be used to diagnose the finger, lipoma and excision was considered the main treatment option [4].

Conclusions
While lipomas are common benign tumors, ones affecting the hand and digits are rare. This case presentation aims to contribute to the literature on lipomas, specifically articles addressing lipomas of the index and middle fingers, even if those types of lipomas are rare, to emphasize the importance of considering it as a differential diagnosis. Total excision of such lipomas is considered to be the surgical method that is preferred by most plastic and hand surgeons. This article aims to report and highlight the satisfactory outcomes after total excision of such lipomas and restoring the function as well as the cosmetic results of the hand.

Additional Information Disclosures
Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.