• Desmoid-type fibromatosis
• Neuromuscular choristoma
• Sciatic nerve
• Undergrowth

Macrodactyly is a rare congenital malformation characterized by an increase in the size of all structures of a digit, accounting for less than 1% of all congenital upper extremity conditions.

We report a case involving a 49-year-old woman who presented for the first time with untreated, radial-sided hand macrodactyly. We performed soft tissue debulking, amputation, median nerve neurotomy and coaptation, and carpal tunnel release. At the 6-year follow-up, no significant growth was observed in the bone or soft tissue of the affected area.

Tissue overgrowth in patients with progressive macrodactyly can continue and progress excessively with age. Median nerve neurotomy and coaptation play a crucial role in preventing recurrence of the deformity.

• Macrodactyly
• Surgery
• Management
• Hand
• Case report

• Humans
• Lipoma/surgery
• Lipoma/pathology
• Lipoma/diagnosis
• Median Nerve/pathology
• Median Nerve/surgery
• Peripheral Nervous System Neoplasms/surgery
• Peripheral Nervous System Neoplasms/pathology
• Peripheral Nervous System Neoplasms/diagnosis
• Female
• Median Neuropathy/surgery
• Median Neuropathy/diagnosis
• Median Neuropathy/pathology
• Magnetic Resonance Imaging
• Diagnosis, Differential
• Adult
• Middle Aged
• Hamartoma/surgery
• Hamartoma/pathology
• Hamartoma/diagnosis
• Male
• Nerve Compression Syndromes/surgery
• Nerve Compression Syndromes/etiology
• Nerve Compression Syndromes/diagnosis

• Humans
• Nerve Sheath Neoplasms/diagnosis
• Nerve Sheath Neoplasms/surgery
• Nerve Sheath Neoplasms/pathology
• Neurilemmoma/diagnosis
• Neurilemmoma/surgery
• Peripheral Nervous System Neoplasms/diagnosis
• Peripheral Nervous System Neoplasms/surgery
• Pain
• Peripheral Nerves

• Everolimus
• Lipomatosis
• Neuropathy
• Peripheral nerves
• Sequencing
• mTOR

• hamartoma
• median neuropathy
• peripheral nerve tumor

• fibrolipomatous hamartoma
• lipofibromatous hamartoma
• lipomatosis of the nerve
• macrodactyly
• macrodystrophia lipomatosa
• overgrowth

• P30 CA015083 NCI NIH HHS

• PIK3CA
• PIK3CA-related overgrowth spectrum
• lipomatosis
• macrodactyly
• molecular pathology
• segmental overgrowth
• targeted therapy

Recurrent missense mutations of the PIK3CA oncogene are among the most frequent drivers of human cancers. These often lead to constitutive activation of its product p110α, a phosphatidylinositol 3-kinase (PI3K) catalytic subunit. In addition to causing a broad range of cancers, the H1047R mutation is also found in affected tissues of a distinct set of congenital tumors and malformations. Collectively termed PIK3CA-related disorders (PRDs), these lead to overgrowth of brain, adipose, connective and musculoskeletal tissues and/or blood and lymphatic vessel components. Vascular malformations are frequently observed in PRD, due to cell-autonomous activation of PI3K signaling within endothelial cells. These, like most muscle, connective tissue and bone, are derived from the embryonic mesoderm. However, important organ systems affected in PRDs are neuroectodermal derivatives. To further examine their development, we drove the most common post-zygotic activating mutation of Pik3ca in neural crest and related embryonic lineages. Outcomes included macrocephaly, cleft secondary palate and more subtle skull anomalies. Surprisingly, Pik3ca-mutant subpopulations of neural crest origin were also associated with widespread cephalic vascular anomalies. Mesectodermal neural crest is a major source of non-endothelial connective tissue in the head, but not the body. To examine the response of vascular connective tissues of the body to constitutive Pik3ca activity during development, we expressed the mutation by way of an Egr2 (Krox20) Cre driver. Lineage tracing led us to observe new lineages that had normally once expressed Krox20 and that may be co-opted in pathogenesis, including vascular pericytes and perimysial fibroblasts. Finally, Schwann cell precursors having transcribed either Krox20 or Sox10 and induced to express constitutively active PI3K were associated with vascular and other tumors. These murine phenotypes may aid discovery of new candidate human PRDs affecting craniofacial and vascular smooth muscle development as well as the reciprocal paracrine signaling mechanisms leading to tissue overgrowth.

An association between obesity and carpal tunnel syndrome is found in many epidemiological studies. Therefore, there is a need to evaluate the physiopathological links that could explain the association between these two entities. Ectopic adipose tissue is responsible for metabolic syndrome and inflammation, and is a major risk factor for diabetes and cardiovascular diseases. Taking these elements into consideration, we conducted an extensive literature revision of the subject, considering as ectopic fat-related mechanisms the following: (a) the direct compression and the association with the metabolic syndrome of the fat deposition around the wrist, (b) the insulin resistance, dyslipidemia, inflammatory, and oxidative mechanisms related to the central deposition of the fat, (c) the impaired muscle contraction and metabolism related to myosteatosis. Each section presents the cellular pathways which are modified by the ectopic deposition of the adipose tissue and the impact in the pathogeny of the carpal tunnel syndrome. In conclusion, the experimental and clinical data support the epidemiological findings. Efforts to reduce the obesity epidemics will improve not only cardio-metabolic health but will reduce the burden of the disability-free life expectancy due to the carpal tunnel syndrome.

• carpal tunnel syndrome
• central obesity
• metabolic syndrome
• myosteatosis
• obesity

A 9-year-old girl was investigated for a long-standing soft tissue swelling in her ring digit that recently developed tenderness and rapid growth within the last 3 months before presentation. Exploration of the swelling was done meticulously with total excision of the swelling from within its attachment to the digital nerve. The swelling was then sent for histopathological examination. The pathology report stated the presence of mature adipose tissue intersected by fiprocellular collagenic stroma infiltrating perineurium, epineurium, and nerve fascicles, which established the diagnosis of lipofipromatous hamartoma (LFH) of the nerve. LFH is a rare benign neoplasm that mainly affects the median nerve, but other nerves all over the body were also reported. Women are more affected than men.

• choristoma
• hamartoma
• intraneural ganglion cyst
• nerve
• perineural spread