Recurrent Parosteal Lipoma of the Mandible: A Case Report and Literature Review

ABSTRACT

While lipomas commonly arise in adipose‐rich subcutaneous tissues of the trunk/extremities, parosteal lipomas involving the mandible represent exceptionally rare entities. This novel case demonstrates successful surgical management of recurrent mandibular parosteal lipoma, the first documented craniofacial recurrence. We emphasize early intervention guided by CT/MRI and intraoperative assessment to ensure complete en bloc resection with adequate margins. Despite their typically low recurrence rate, meticulous subperiosteal dissection addressing juxtacortical adherence proves critical to mitigate complications and recurrence risks in anatomically complex regions.

Rare recurrent mandibular periosteal lipoma.

Summary.

• Parosteal lipomas of the jawbone are rare, with no recurrent cases reported to date.

• Their firm adherence to underlying bone dictates surgical constraints.

• Surgeons should utilize thorough preoperative evaluation and intraoperative assessment to achieve definitive initial resection during the first surgical intervention.

1. Introduction

Lipomas, slow‐growing benign soft tissue neoplasms predominantly located in adipose‐rich subcutaneous tissues of the trunk and extremities, are characterized histologically by well‐differentiated adipocytes with low malignant transformation potential [1]. While typically confined to subcutaneous or deep soft tissue compartments, rare variants may develop in juxtacortical locations, termed parosteal lipomas [2]. Within the oral and maxillofacial region, lipomas most frequently arise in adipose‐dense areas such as the buccal or cervical regions, with intraoral presentations being uncommon and those involving extraperiosteal mandibular or maxillary structures remaining exceptionally rare [3, 4]. Surgical excision constitutes the standard therapeutic approach, yielding favorable prognoses with low recurrence rates [4]. This study details a recurrent parosteal lipoma localized in the left mandibular vestibular sulcus, successfully managed through targeted intervention.

2. Case Presentation

2.1. Case History

A 42‐year‐old male presented to our institution with a chief complaint of a progressively enlarging soft mass in the left mandibular gingival region persisting for 2 years. The lesion was notably asymptomatic, lacking associated pain, paresthesia, or functional impairment. Medical history revealed surgical excision of a histopathologically confirmed lipoma at the identical anatomical site 8 years prior, followed by a 6‐year asymptomatic period. Recurrent tumor development was observed 2 years preceding the current presentation, characterized by a soft, non‐tender mass. Despite its presence, no immediate intervention was pursued due to the absence of symptoms. Recent self‐reported progressive enlargement prompted the patient to seek medical evaluation and request therapeutic intervention.

2.2. Investigations and Treatment

Intraoral evaluation revealed moderate oral hygiene with a 1.5 × 1.0 × 0.5 cm soft, well‐circumscribed mass localized to the buccal vestibular sulcus apical to the left mandibular first molar (Figure 1). The lesion exhibited a smooth mucosal surface without nodularity, demonstrating non‐fluctuant consistency, moderate mobility, and absence of tenderness upon palpation. Dental examination identified agenesis of the left mandibular second premolar, with adjacent teeth showing no percussion sensitivity or evidence of pathological periodontal pocket formation (< 4 mm probing depth). A prominent mucosal scar was observed along the superior lesion margin. Bilateral cervicofacial lymph node palpation revealed no pathological adenopathy.

FIGURE 1.

Intraoral photograph demonstrates a mass located in the buccal vestibule at the root level of the left first molar, with the yellow arrow indicating the mucosal scar from the previous surgery.

Preoperative cone‐beam computed tomography (CBCT) demonstrated preserved cortical continuity of the left mandible without evidence of osteolytic destruction or periosteal reaction (Figure 2). A well‐demarcated hypodense lesion (1.5 × 1.0 cm) was visualized in intimate anatomical proximity to the lateral mandibular cortex, maintaining distinct tissue‐plane separation from adjacent muscular and neurovascular structures (Figure 2).

FIGURE 2.

Preoperative CBCT imaging demonstrates a well‐defined low‐density mass lateral to the cortical bone, as indicated by the green arrow, with intact cortical continuity and no evidence of osseous destruction.

Based on comprehensive evaluation integrating medical history, clinical findings, and imaging characteristics, a provisional diagnosis of mandibular vestibular sulcus lipoma was established. Under informed consent, the patient underwent local anesthesia‐assisted surgical excision. A transverse mucosal incision along the superior lesion margin allowed adequate exposure, followed by meticulous dissection to identify and preserve the mental neurovascular bundle anteriorly (Figure 3). Subsequent subepithelial dissection revealed firm adherence between the lesion's deep surface and mandibular periosteum, necessitating sharp periosteal release to achieve complete en bloc resection. Hemostasis was achieved via compression, and primary closure was performed using nonresorbable sutures.

FIGURE 3.

The intraoperative image shows a yellow‐white mass exposed; after dissection from the periosteum, complete enucleation of the mass was achieved.

2.3. Outcome and Follow‐Up

The excised specimen was fixed in 10% neutral buffered formalin for histopathological evaluation (Figure 4), which confirmed the diagnosis of mature adipocytic proliferation consistent with lipoma (Figure 5). Postoperative recovery proceeded without complications, with suture removal performed at one‐week follow‐up demonstrating uneventful mucosal healing. Ongoing telephonic surveillance at 3‐month intervals (current duration: 1 year) has shown no clinical evidence of recurrence.

FIGURE 4.

The completely excised tumor specimen measures 1.5 × 1.0 × 0.5 cm.

FIGURE 5.

Histology demonstrates proliferating mature adipocytes exhibiting characteristic unilocular cytoplasmic vacuolization. These adipocytes are interspersed within fibrous septa of variable thickness containing cytologically bland spindle cells.

3. Discussion

Lipoma, one of the most prevalent benign mesenchymal soft tissue tumors composed of mature adipocytes, can develop in any anatomical region containing adipose tissue, with predominant occurrence in subcutaneous tissues of the trunk and extremities [1]. Epidemiological studies indicate that oral and maxillofacial lipomas account for approximately 1%–4% of all cases, while intraoral manifestations remain relatively uncommon. Among oral cavity presentations, the buccal mucosa represents the most frequent site (40.6%), followed by the tongue (17.9%), lips (12.6%), gingiva (8.7%), floor of the mouth (6.8%), and the buccogingival fold and palate (4.8%), with other locations comprising 3.9% of cases [5]. Parosteal lipoma, a rare histological variant representing approximately 0.3% of all lipoma cases, predominantly affects individuals aged 40–60 years. This subtype demonstrates predilection for long bones including the femur, proximal radius, humerus, and tibia, as well as the clavicle and pelvic bones [6]. Notably, parosteal lipomas involving craniofacial bones or maxillofacial structures are exceptionally rare, with current documentation limited to sporadic case reports in the medical literature [7, 8].

Parosteal lipoma, first documented by Seerig in 1836 as “periosteal lipoma” due to its perceived origin from the periosteum, has undergone significant nosological evolution. Subsequent literature introduced alternative designations including subperiosteal and extraperiosteal lipoma based on anatomical positioning. Contemporary scholars have challenged the traditional nomenclature, arguing against periosteal cellular origins given the absence of neoplastic progenitor cells within the periosteum, thus advocating for the more accurate term “extraperiosteal lipoma” [9, 10]. This terminological refinement culminated in Power's formal classification as “parosteal lipoma” [9]. Clinically, parosteal lipomas typically manifest as asymptomatic soft tissue masses. Symptomatic presentations may occur secondary to mass effect, particularly when compressing adjacent neuromuscular structures, potentially resulting in localized paresthesia or motor dysfunction. Radiologically, these lesions demonstrate pathognomonic features including well‐circumscribed hypodense masses on CT imaging, frequently exhibiting intimate association with underlying cortical bone. Characteristic osseous changes may accompany these lesions, ranging from reactive cortical thickening to mature osseous excrescences. Miller's classification system (1992) stratifies parosteal lipomas into four distinct subtypes based on osteogenic differentiation patterns: Type I: Absence of osseous components; Type II: Pedunculated exostosis formation; Type III: Sessile exostosis development; Type IV: Plaque‐like osteochondral metaplasia [11]. Although parosteal lipomas are histologically benign, their progressive growth can result in substantial tumor volume. Furthermore, manifestations such as nerve compression causing paresthesia or radiographically evident cortical destruction may mimic malignant or locally aggressive neoplasms. The diagnostic challenge is compounded by this entity's rarity and non‐specific imaging characteristics, which frequently confound preoperative assessment [2, 12].

Surgical resection represents the primary therapeutic modality for parosteal lipomas [13]. Simple enucleation is feasible for most lesions; however, cases with dense adhesion to the periosteum or associated osseous destruction of the underlying bone require extended resection, including partial periosteal removal or osseous resection [4, 14]. To date, no case reports of postoperative recurrence of parosteal lipomas in the jaw bone have been documented, underscoring the effectiveness of appropriately tailored surgical approaches based on tumor‐bone relationships.

The patient's history reveals previous resection of a histopathologically confirmed lipoma at the identical anatomical site 8 years prior. Although definitive determination of the initial lesion's anatomical plane remains speculative due to unavailable surgical records, Figure 1 demonstrates precise topographic correspondence between the current tumor and a residual mucosal scar at the superior lesion margin. Critical analysis of temporal–spatial recurrence patterns (identical site, equivalent histopathology) coupled with established recurrence risk profiles substantiates the diagnosis of recurrent parosteal lipoma [15]. The lesion demonstrated intimate anatomical proximity to the left nervus mentalis, though no neuropathic symptoms (e.g., paresthesia) were clinically evident. Progressive enlargement risked mechanical compression or traction neuropathy, potentially inducing lower lip sensory dysfunction. While parosteal lipomas are histologically benign, persistent growth may precipitate osteolytic invasion (observed in 8%–12% of juxtacortical cases) or compressive sequelae affecting adjacent musculature and neural structures [7]. Therefore, complete surgical excision is strongly recommended upon early detection of parosteal lipomas to achieve optimal clinical outcomes.

4. Conclusions

Although parosteal lipomas demonstrate low recurrence rates, this favorable outcome is contingent upon performing a definitive initial surgical procedure guided by comprehensive preoperative assessment and intraoperative findings. Should tumor recurrence be detected at the primary surgical site and confirmed through diagnostic evaluation, expeditious surgical intervention is warranted to prevent potential complications.

Author Contributions

Taiqi Cheng: conceptualization, data curation, writing – original draft, writing – review and editing. Zhiyu Ma: supervision, writing – original draft, writing – review and editing. Xing Yan: conceptualization, supervision, writing – review and editing.

Ethics Statement

This case report has been approved by the Ethics Review Committee of Beijing Friendship Hospital Affiliated to Capital Medical University, with the number BFHHZS20240205.

Consent

The authors confirm that written consent for submission and publication of this case report, including images and associated text, was obtained from the patient in line with COPE guidance.

Conflicts of Interest

The authors declare no conflicts of interest.

Cheng T., Ma Z., and Yan X., “Recurrent Parosteal Lipoma of the Mandible: A Case Report and Literature Review,” Clinical Case Reports 13, no. 10 (2025): e70908, 10.1002/ccr3.70908.

Data Availability Statement

The data underlying this article will be shared upon reasonable request to the corresponding author.