Distribution of intramuscular giant lipomas in the functional compartments of the forearm: a report of 12 cases

Abstract

Purpose The aim of this study was to investigate the distribution of intramuscular giant lipomas in the functional compartments of the forearm and to compare their clinical, radiological and histopathological features with those reported in the current literature. Methods The study included 12 patients who were surgically treated for intramuscular lipomas > 5 cm in size located in the forearm that had been confirmed histopathologically between April 2006 and March 2017. Data about the patients with respect to age, sex, affected side, localisation of the lipomas in the forearm functional compartments, size, histopathological features and recurrence were collected. According to the clinical complaints, direct radiography and magnetic resonance imaging were applied. Results The average diameter was 6.5 cm (range: 5.5–9 cm). All lipomas had a well-defined border. All the patients presented with soft-tissue masses that were painless in seven patients. Five patients had nerve compression symptoms. When the lipomas were classified according to the functional compartments of the forearm, six of them were located in the superficial volar compartment, two in the deep volar compartment, two in the deep dorsal compartment and two in the lateral compartment. All lipomas were surgically removed by marginal excision. None had complications or recurrence at a mean of 6.5 years follow-up (range: 1–12 years) after surgery. Conclusions Intramuscular lipoma is a relatively uncommon tumour, especially in the forearm. Because of the proximity to the neurovascular structures in the forearm, excision of lipomas should be performed with care and include wide incisions. Additionally, knowing the anatomical features of the compartment where the lipoma is localised in the forearm is important in planning surgery to enable easier dissection of the lipoma and lessen the risk of damage to adjacent neurovascular structures. Level of evidence Level 4

Forearm mass dilemma during a pediatric hand surgery medical mission: a case report

“…Less commonly they are deep and referred to as deep-seated lipomas. [3][4][5] Deep-seated lipomas can be intermuscular or intramuscular and infiltrative, noninfiltrative, or mixed. 3,4 Intramuscular lipomas account for approximately 1% of all lipomas.…”

“…6,7,9,10 Patient cases in the upper extremity may involve the triceps, flexor digitorum profundus, flexor digitorum superficialis, interosseous, biceps, brachialis, and brachioradialis muscles. 2,5,10,11 Intramuscular lipomas typically present as an asymptomatic mass or swelling, and when located in the forearm may produce nerve compression that is caused by adjacent neurovascular structures. 1,5,10,11 Lipomas larger than 5 cm are categorized as giant lipomas, and with enlargement a liposarcoma should be considered.…”

“…2,5,10,11 Intramuscular lipomas typically present as an asymptomatic mass or swelling, and when located in the forearm may produce nerve compression that is caused by adjacent neurovascular structures. 1,5,10,11 Lipomas larger than 5 cm are categorized as giant lipomas, and with enlargement a liposarcoma should be considered. 11 One study of soft-tissue masses (n = 95) demonstrated that as tumor size increased, malignancy probability increased.…”

“…10 A series (n = 12) of forearm intramuscular lipomas demonstrated an average size of 6.5 cm, none of which were malignant. 5 A study of giant lipomas (n = 8, 4 forearms) had an average size of 10 cm, with one diagnosed as a well-differentiated liposarcoma. 11 Although 99% of lipomas are benign, it is necessary to differentiate benign from malignant tumors prior to excision.…”

Tumor complejo intramuscular de antebrazo: a proposito de un caso

“…En la etiopatogenia, hay hallazgos que sugieren fuertemente una asociación con trastornos focales neurogénicos y miogénicos en la lesión . Estas alteraciones podrían modular las características de crecimiento infiltrante de un lipoma intramuscular(22) En cuanto al gran tamaño y localización del tumor en lo específico, se determina que una tumoración profunda de más de 5 cm de diámetro, no necesariamente dolorosa, que crece o reaparece después de extirpada, debe considerarse un sarcoma mientras no se demuestre lo contrario y proceder en consecuencia (3)(23) De tal forma , es necesario completar el estudio de la lesión y derivar al paciente de forma rápida a un centro de referencia para su tratamiento específico si no se cuenta con los especialistas adecuados.La cirugía de extirpación completa del tumor es el tratamiento de elección para los lipomas intramusculares (2)(3)(25) La excisión marginal de un área bien circunscrita y una amplia excisión con márgenes libres en áreas infiltrantes, en lo posible , ayudará en la prevención de recurrencias (2)(25) En el tratamiento de los lipomas intramusculares sintomáticos, no es necesaria una biopsia previa en los casos típicos(28) El riesgo de recidiva se estima en un 0-5% en las formas intermusculares y se ha descrito hasta un 19% de recidivas en las formas intramusculares(10) Tener en cuenta si hay recurrencia local , Márgenes quirúrgicos positivos o reporte de malignidad en la biopsia, deberá derivarse el paciente de inmediato a Oncología para comenzar tratamiento adyuvante ,como la Radioterapia , tan pronto sea posible(3) En cuanto a la localización específica de estos tumores en el antebrazo , su frecuencia es baja , menor a un 8 % según algunas series (3) por tanto se considera al lipoma intramuscular un tumor infrecuente en la región del antebrazo(24) y hay escasos estudios sobre la presencia en los distintos compartimentos antebraquiales de estos tumores(24) Nuestro caso clínico considera la proximidad de las estructuras neurovasculares del antebrazo en relación al tumor y por tanto la cirugía debe considerar abordajes amplios con una cuidadosa disección (25) Es así , que estos tumores pueden provocar síntomas de compresión nerviosa (24)(26) Según el tamaño y localización tumoral en el antebrazo , puede comprometerse el nervio radial , mediano o ulnar(27) Como debilidad del estudio en relación al caso presentado está la no realización de importantes examenes de imágenes , Resonancia y TAC . Lo anterior dado por la intolerancia involuntaria del paciente al examen referido , no obstante el análisis clínico y ecográfico sumado a la experiencia de un equipo de especialistas , determinó el manejo definitivo quirúrgico ya expuesto con un resultado favorable a la fecha .El caso clínico presentado , posiciona en importancia a un determinado tipo de tumores de partes blandas , de contenido adiposo , profundos en sulocalización .…”