Anomalous flexor digitorum superficialis muscle belly: an unusual case of mass in the palm

Accessory first lumbrical muscle within the carpal tunnel: a case report

Carpal tunnel syndrome is the most common entrapment neuropathy in the upper extremity. Palmaris longus, flexor digitorum superficialis, and lumbricals have infrequently been reported as causes of nerve compression. During routine Korean cadaver dissection, we incidentally identified an anatomic variant of first lumbrical muscle within the carpal tunnel in both wrists. The aberrant musculature originated from the radial side of the second FDS muscle at distal forearm level, running separately across the wrist beneath the flexor retinaculum. The dissected anomalous muscle was identified as an additional muscle belly of the first lumbrical muscle. Compression of the median nerve at the wrist might rarely be caused by the presence of such a tendon or muscle anomaly found in this study. Surgeons should be aware of possible anatomic variations in the carpal tunnel, and be prepared to modify their surgical plan accordingly.

An Analysis of Profundus Tendon Repairs After Distal Phalanx Amputation in a Cadaveric Model of Little Finger Superficialis Deficiency

PURPOSE

The flexor digitorum superficialis tendon to the little finger (FDS-5) has been observed to have a higher degree of functional and structural variation than the FDS of other digits. FDS-5-deficient individuals necessarily rely on the flexor digitorum profundus tendon to the little finger (FDP-5) for flexion in their little fingers. FDS-5 deficient patients who experience a considerable injury to their FDP-5 are therefore at a risk of losing substantial little finger flexion. The purpose of this study was to evaluate the degree of flexion of the little finger at the metacarpophalangeal and proximal interphalangeal (PIP) joints in a cadaveric model of FDS-5 deficiency following amputation of the distal phalanx.

METHODS

Ten fresh-frozen cadaveric upper extremities with no prior trauma were used. Loads were applied to the FDP-5. Flexion at the PIP and metacarpophalangeal joints was measured in degrees with a goniometer. Little finger flexion testing was conducted under 5 different conditions: "baseline," "FDS-deficient," "no repair," "bone anchor" repair, and "A4 pulley" repair.

RESULTS

The results were as follows: (1) no significant differences in the flexion between baseline and FDS-deficient conditions; (2) a significant decline in PIP flexion in the no repair condition after FDP-5 division compared with the FDS-deficient condition; (3) a significant restoration in PIP flexion in both surgical repair groups compared with the no repair group; and (4) no significant differences in PIP flexion between the A4 pulley and bone anchor groups.

CONCLUSIONS

The bone anchor repair and the A4 pulley repair demonstrate similar abilities to restore flexion of the little finger at the PIP joint to baseline levels in this cadaveric model.

CLINICAL RELEVANCE

A clinical protocol is yet to be established for the surgical treatment in FDS-5-deficient patients requiring amputation of the distal phalanx of the little finger. This study aims to address this area of uncertainty by comparing the little finger flexion after 2 different approaches to profundus tendon reattachment that may be applicable in this clinical scenario.

Bilateral flexor digitorum superficialis brevis of the little finger: a rare cause of carpal tunnel syndrome

An anatomical variant of flexor digitorum superficialis brevis is an uncommon condition that may be a pitfall in diagnosing carpal tunnel syndrome, involving palpable mass and even characteristic symptoms. We present an unusual case of bilateral symptomatic carpal tunnel syndrome related to the presence of a flexor digitorum superficialis brevis muscle of the little finger, and a critical review of the literature.

Clinical Relevance and Immunohistochemical Patterns of Silent Pituitary Adenomas: 10 Years of Single-centre Experience

BACKGROUND

Silent pituitary adenomas are clinically non-functional (i.e., without clinically evident pituitary hormone production).

INTRODUCTION

The aim of this study was to investigate subjects with silent pituitary adenomas for possible variations in their clinical status.

METHODS

A total of 102 patients who had undergone surgery for pituitary adenoma and had been diagnosed with silent pituitary adenoma was included in the study. The patients' preoperative and postoperative hormonal parameters and magnetic resonance imaging (MRI) features were collected, and pathological specimens were re-evaluated.

RESULTS

Immunohistochemistry results of the 102 patients were as follows: hormone-negative adenomas (n=35) 35.5%; FSH+LH-positivity (n=32) 31.3%; ACTH-positivity (n=11) 10.7%; α-subunit- positivity (n= 9) 8.8%; prolactin-positivity (n=8) 7.8%; GH-positivity (n=6) 5.4%; and plurihormonal adenoma (n=1). The mean sizes of SGA, SGHA, and SCA were 28.0±12.7, 30.0±16.0, and 27.7±8.9mm (p>0.05), respectively. With the exception of silent gonadotroph adenomas (SGAs), female gender dominance was shown in patients with silent growth hormone adenoma (SGHA) and silent corticotroph adenoma (SCA). Although no clinical relevance was observed in relation to hormonal excess, preoperative GH (4.21±4.6, vs. 0.27±0.36 p=0.00) was slightly more elevated in SGHA than in GH-negative adenomas. Additionally, preoperative basal ACTH values (47.3±28.7 vs. 23.9±14.4, p=0.003) were also higher in SCA compared to the other types. Our findings revealed SCAs to be of more aggressive behaviour than SGHAs and SGAs due to invasiveness in radiological imaging, their elevated re-operation, and postoperative ACTH values.

CONCLUSION

Silent pituitary adenomas represent a challenging diagnostic tumour group. Careful initial evaluation of patients with pituitary adenomas should consider any mild signs and symptoms of functionality, particularly in cases of GH- and ACTH-secreting adenomas.

The anatomy and function of a bilateral accessory flexor digitorum superficialis muscle: A case report and review of literature

Anatomical variations of the flexor digitorum superficialis (FDS) include variations of the muscle belly and/or tendon. We present a case of a bilateral accessory FDS muscle and tendon. Dissection was performed in a male specimen (56 years), where an unusual variation was found: a bilateral accessory FDS muscle and tendon. The accessory FDS muscle belly originated at the medial epicondyle, between the tendinous portions of the FDS and flexor carpi radialis, with average dimensions of 70mm in length and 23mm in width. The accessory FDS muscle belly was innervated by the median nerve. After developing a strong tendon, with a length of 51mm (right) and 85mm (left) and width of approximately 9.5mm, the accessory FDS inserted into the dorsal muscle belly of the main FDS. To further analyze the variation, the left accessory FDS muscle and tendon were separated from the adjacent tissues at the elbow and kept attached at the wrist. On a custom jig, 10N were applied sequentially to the main and accessory FDS separately and then together to access their function. Loading of the main FDS muscle resulted in flexion of the fingers with accentuation of the ulnar rays. Loading of the accessory FDS caused flexion of all four long fingers. We described a rare case of an accessory flexor digitorum superficialis, which may assist surgeons with clinical decisions. Surgeons should be aware of variability in forearm anatomy.

Accessory muscle of the flexor digitorum superficialis and its clinical implications

Anatomical variations of the flexor digitorum superficialis (FDS) muscle and tendon unit are frequently reported by anatomists and clinicians. Anatomical muscle variations of the FDS and its tendons may include variations of muscle belly, presence of accessory or duplicate tendons, abnormal tendon connections, and absence of muscle or tendon components. Such variations may or may not have clinical implications. This report presents a case not described previously: a unilateral accessory muscle of the flexor digitorum superficialis which was connected by a thick tendon to the flexor digitorum superficialis muscle; it was directed proximally to the insertion of the medial epicondyle of the humerus, next to the superficialis head of the pronator teres muscle. The belly of the accessory muscle was positioned anterior to the median and anterior interosseous nerve. This anatomical variation is known as type V in the classification of Elliot et al. The knowledge of these anatomical variations helps hand surgeons interpret the clinical examination, particularly in the evaluation of patients who have suffered tendon injuries or show sign s of possible peripheral nerve entrapment.

A rare accessory muscle in the hand--the flexor digitorum superficialis indicis

Accessory muscles are easily overlooked during imaging evaluation. Although usually discovered incidentally, they are occasionally symptomatic. With increasing utilization of cross-sectional imaging, the radiologist should be prepared to readily identify these anomalous muscles. It is particularly important to distinguish these anatomical variants from soft-tissue tumors prior to invasive intervention, reserving biopsy and surgery for children who are symptomatic. This report discusses a case of a flexor digitorum superficialis indicis muscle, an extremely rare but well-described accessory muscle, presenting as a painful mass in a 15-year-old girl. The report includes the clinical presentation, radiologic findings, and the significance to management.

Carpal tunnel syndrome secondary to an accessory flexor digitorum superficialis muscle belly: case report and review of the literature

Anomalous muscles usually do not cause symptoms but are of academic interest mainly discovered during cadaveric dissection. An aberrant muscle belly arising from the index finger flexor digitorum superficialis tendon causing carpal tunnel syndrome is rare. The management of such an anatomical variant is dependent on whether the median nerve compression is associated with a palpable mass. A brief case highlighting important management principles along with a complete literature review is reported.

Painful, palpable and pathological: anomalous flexor digitorum superficialis brevis in the palm, comparative anatomical context, and an updated classification of anomalies of the flexor digitorum superficialis

Anomalies of the flexor digitorum superficialis are rare and can present a diagnostic dilemma. Patients present with a painful or palpable mass, or symptoms of carpal tunnel syndrome. This review article summarizes previously reported anomalies of the flexor digitorum superficialis, reports a further case, and proposes a new classification.

Anomalous large unique muscle belly of flexor digitorum superficialis and the absence of palmaris longus in the forearm

Anomalies of muscles of the upper extremity are frequently encountered and anatomic variations of the flexor digitorum superficialis (FDS) muscle-tendon unit are frequently reported by anatomists and clinicians. FDS anomalies can be in forms of tendon interconnections, substitution, absence or muscle belly variations and most of the times the anomalies of FDS produce few clinical symptoms. We report a rare and unusual case of FDS anomaly with a unique and large muscle belly. The deformity is type V according to the classification of Elliot et al. in which the muscle belly extends to four digits (the index, middle, ring and little finger) in the right hand of patient and there is absence of the palmaris longus tendon. The hand surgeon should be able to realise all variations of the FDS tendon and should be prepared for unexpected findings during surgery.

Anomalous flexor digitorum superficialis muscle belly presenting as a mass within the palm

Anomalies of the flexor digitorum superficialis muscle are extremely uncommon and usually present as a painful mass or pseudotumour within the palm. Diagnosis may be difficult because many other soft tissue tumours (lipomas, ganglions, giant cell tumours and hamartomas) may present similarly. Magnetic resonance imaging helps to define the extent and characteristics of this anomalous muscle belly and to distinguish it from a soft tissue sarcoma, whereas plain radiographs are of little value. Three types of flexor digitorum superficialis muscle anomalies have been described, and treatment consists of subtotal or total surgical debulking of the mass if symptoms persist or if the diagnosis is in question. Most patients have complete resolution and full recovery. To date, 20 cases have been reported in the literature, usually involving the right small finger. In the present paper, the case of an anomalous flexor digitorum superficialis muscle in a 17-year-old male patient's left index finger is reported. Symptoms were relieved following surgical debulking and hand-based occupational therapy.

Anatomical variations of the carpal tunnel structures

There are many anatomical variations in and around the carpal tunnel that affect the nerves, tendons and arteries in this area. Awareness of these variations is important both during the clinical examination and during carpal tunnel release. The purpose of the present review is to highlight recognized anatomical variations within the carpal tunnel including variation in nerve anatomy, tendon anatomical variants, vascular anatomical variations and muscle anatomical variations.

A flexor carpi radialis brevis muscle with an anomalous origin on the distal radius

This report describes an anomalous muscle on the volar aspect of the wrist alongside an underdeveloped pronator quadratus. Identified during cadaveric dissection, the longitudinally oriented muscle originated on the distal radial metaphysis, a location occupied typically by the insertion of the pronator quadratus. The aberrant muscle formed a tendon distally, which inserted along with the flexor carpi radialis tendon at the base of the index metacarpal.

Wrist joint ganglion presenting as a painless mass in the palm: report of 2 cases

Ganglions occur commonly in the wrist and arise from the radiocarpal and intercarpal joints. Although ganglions present commonly as masses on the dorsal or volar surface of the wrist, ganglions from wrist joints appear rarely at other locations in the hand. We report 2 cases of ganglions arising from wrist joints that presented as painless masses in the center of the palm without signs or symptoms of median or ulnar nerve compression. Surgical treatment required extensile exposure to trace the proximal stalks to their joints of origin. Knowledge of the possibility that a painless mass in the palm could be a ganglion arising from a joint in the wrist allows proper presurgical planning and informed consent.

Anomalies of the flexor digitorum superficialis muscle

Three anomalies of the human flexor digitorum superficialis are presented. The normal development of this muscle from the amphibian to the human is discussed and the described anomalies of the muscle in humans classified.