Pachydermoperiostosis of the complete type: A novel missense mutation c.101T > C in the SLCO2A1 gene

Pseudoacromegaly-A challenging entity in the endocrine clinic: A systematic review

OBJECTIVE

Pseudoacromegaly encompasses conditions with features of acromegaly/gigantism, but no growth hormone (GH) or insulin-like growth factor-1 (IGF-1) excess. We aimed to review published pseudoacromegaly cases evaluated due to clinical suspicion of acromegaly.

DESIGN/PATIENTS

PubMed/Medline search was conducted to identify reported pseudoacromegaly cases, which were systematically reviewed to ensure they met eligibility criteria: (1) presentation suggestive of acromegaly; (2) acromegaly excluded based on normal GH, IGF-1 and/or GH suppression on oral glucose tolerance test (OGTT-GH); (3) diagnosis of the pseudoacromegaly condition was established. Data were retrieved from each case and analysed collectively.

RESULTS

Of 76 cases, 47 were males, mean ages at presentation and at first acromegaloid symptoms were 28 ± 16 and 17 ± 10 years, respectively. Most common conditions were pachydermoperiostosis (47%) and insulin-mediated pseudoacromegaly (IMP) (24%). Acromegaloid facies (75%) and acral enlargement (80%) were the most common features. Measurement of random GH was reported in 65%, IGF-1 in 79%, OGTT-GH in 51%. GH excess was more frequently excluded based on two tests (53%). Magnetic resonance imaging (MRI) was performed in 30 patients, with pituitary adenoma or hyperplasia being reported in eight and three patients, respectively. Investigations differed between cases managed by endocrine and non-endocrine specialists, the former requesting more often IGF-1, OGTT-GH and pituitary MRI.

CONCLUSIONS

Pseudoacromegaly is a challenging entity that may be encountered by endocrinologists. Pachydermoperiostosis and IMP are the conditions most often mimicking acromegaly. Adequate assessment of GH/IGF-1 is crucial to exclude acromegaly, which may be better performed by endocrinologists. Pituitary incidentalomas are common and require careful judgement to prevent unnecessary pituitary surgery.

Eicosanoid profiling in patients with complete form of pachydermoperiostosis carrying SLCO2A1 mutations

Pachydermoperiostosis (PDP) is a genetic disease characterized by digital clubbing, periostosis, and pachydermia caused by mutated HPGD or SLCO2A1. Plasma prostaglandin (PG)E₂ levels are increased in these patients. However, other eicosanoids have not been quantitated. We aimed to quantitate plasma eicosanoid levels in four patients carrying SLCO2A1 mutations by high-performance liquid chromatography-tandem mass spectrometry. PGE₂ level was elevated in all patients; PGD₂ and 11β-PGF₂ α levels were also increased in some patients, whereas eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid levels were decreased in all patients. Our data indicate a dysfunctional eicosanoid homeostasis and varied levels of PG in patients with a complete form of PDP carrying SLCO2A1 mutations. PGE₂ levels seem to mostly affect the symptoms, with other eicosanoids possibly having a minor effect.

Recent advances in studies of SLCO2A1 as a key regulator of the delivery of prostaglandins to their sites of action

Solute carrier organic anion transporter family member 2A1 (SLCO2A1, also known as PGT, OATP2A1, PHOAR2, or SLC21A2) is a plasma membrane transporter consisting of 12 transmembrane domains. It is ubiquitously expressed in tissues, and mediates the membrane transport of prostaglandins (PGs, mainly PGE₂, PGF_2α, PGD₂) and thromboxanes (e.g., TxB₂). SLCO2A1-mediated transport is electrogenic and is facilitated by an outwardly directed gradient of lactate. PGs imported by SLCO2A1 are rapidly oxidized by cytoplasmic 15-hydroxyprostaglandin dehydrogenase (15-PGDH, encoded by HPGD). Accumulated evidence suggests that SLCO2A1 plays critical roles in many physiological processes in mammals, and it is considered a potential pharmacological target for diabetic foot ulcer treatment, antipyresis, and non-hormonal contraception. Furthermore, whole-exome analyses suggest that recessive inheritance of SLCO2A1 mutations is associated with two refractory diseases, primary hypertrophic osteoarthropathy (PHO) and chronic enteropathy associated with SLCO2A1 (CEAS). Intriguingly, SLCO2A1 is also a key component of the Maxi-Cl channel, which regulates fluxes of inorganic and organic anions, including ATP. Further study of the bimodal function of SLCO2A1 as a transporter and ion channel is expected to throw new light on the complex pathology of human diseases. Here, we review and summarize recent information on the molecular functions of SLCO2A1, and we discuss its pathophysiological significance.

Primary hypertrophic osteoarthropathy related gastrointestinal complication has distinctive clinical and pathological characteristics: two cases report and review of the literature

BACKGROUND

Primary hypertrophic osteoarthropathy (PHO) is a rare disease related to HPGD and SLCO2A1 gene mutation. Gastrointestinal involvement of PHO is even rarer with unknown pathogenesis. Clinical features of GI complication in PHO mimics other auto-immune based bowel entities, such as inflammatory bowel diseases and cryptogenic multifocal ulcerous stenosing enteritis (CMUSE). We aimed to analyze the clinical, genetic, radiological and pathological features of Chinese patients with PHO and determine the difference between PHO patients presenting with and without GI involvement.

METHODS

We reported two PHO cases with gastrointestinal involvement and reviewed all the studies of PHO in Chinese population published from January 1, 2000, to April 30, 2018. Clinical and genetic presentations of PHO in Chinese patients were analyzed. We compared the characteristics of those patients with gastrointestinal involvement against those without.

RESULTS

The two patients were both males with complete-form PHO for more than 10 years. GI related symptoms included diarrhea, chronic gastrointestinal hemorrhage, incomplete intestinal obstruction, anemia, and edema, which were unresponsive to etoricoxib treatment. Radiological examinations revealed segmental intestinal stenosis and thickened intestinal wall. Endoscopic findings included multiple ulcers and mucosal inflammation. Both patients had mutations of SLCO2A1 according to sequence analysis. The surgical pathology revealed chronic inflammation involving the intestinal mucosa and submucosa, similar to histological changes in CMUSE. According to the systemic review of 158 Chinese patients with PHO, 17.2% had gastrointestinal involvement, including peptic ulcer, gastric polyps, hypertrophic gastritis, and segmental intestinal stenosis. Patients with gastrointestinal involvement were more likely to have anemia (40.0% vs. 4.5%, P < 0.001), hypoalbuminemia (16.7% vs. 0.9%, P = 0.003), and myelofibrosis (19.0% vs. 0.9%, P = 0.002) than those without. Most patients with gastrointestinal complication had SLCO2A1 mutation (86.7%, 13 /15).

CONCLUSIONS

Digestive tract involvement is uncommon in patients with PHO and often presents with anemia, and hypoalbuminemia resulted from intestinal inflammation. The intestinal pathologic characteristics are distinct from Crohn's disease but similar to CMUSE. Mutations in SLCO2A1 might be the pathogenic cause of GI involvement of PHO. NSAIDs may not be effective for PHO patients with gastrointestinal complications.

Pachydermoperiostosis: A clinicopathological description

Purpose

To report a case of pachydermoperiostosis (PDP) and a review of the literature.

Methods

A 32-year-old man was referred to our clinic with bilateral eyelid swelling and blepharoptosis. On examination, marked blepharoptosis was noted, and his eyelids were found to be floppy. Systemic examination was significant for clubbing of digits, coarse acromegalic facial features, and furrowing and oiliness of the skin of scalp and forehead.

Results

The patient was diagnosed as a case of PDP. On the brain MRI, the pituitary gland was enlarged, and the border of clivus was irregular. Pituitary and thyroid hormone levels were normal. He underwent bilateral lateral tarsal strip (LTS) procedure to address the eyelid laxity. Histopathologic examination revealed marked sebaceous gland hyperplasia with mucin deposition in the dermis.

Conclusion

Floppy eyelid syndrome, clubbing, and acromegaloid face are main features that could lead to the diagnosis of PDP.

Neurosurgical and Scalp Reconstructive Challenges During Craniotomy in the Setting of Cutis Verticis Gyrata

BACKGROUND

Cutis verticis gyrata (CVG) is a rare condition of the scalp in which thickening of the dermis induces rigid folds and furrows resembling the cerebral cortex. Two forms of primary CVG exist: essential, in which CVG is the only presenting problem, and nonessential, in which the scalp condition occurs along with neuropsychiatric ailments. CVG can also occur secondary to a variety of causes including inflammatory, neoplastic, and metabolic conditions or drug use. A review of the available literature, including description of the epidemiology, pathophysiology, histology, and typical management of CVG, is provided. However, we identified no literature describing the complications of CVG in the setting of a craniotomy.

CASE REPORT

The patient presented here is a 54-year-old man with CVG who presented with occlusion of the M2/M2 branches of the middle cerebral artery, resulting in malignant cerebral edema, requiring emergent management via decompressive craniectomy. Because of the thickening of the scalp, skin incision was complicated by bleeding and difficulty in achieving hemostasis using Raney clips. Plastic surgery was consulted intraoperatively for assistance with complex closure of the wound in a multilayered fashion. Despite this, the patient's postoperative course was complicated by cerebrospinal fluid leakage due to difficulty in approximating the incision during closure. Subsequent cranioplasty was performed jointly between neurosurgery and plastic surgery.

CONCLUSIONS

Despite its rarity, CVG is an important issue for neurosurgeons to understand as it can present complications in performing craniotomy, most notably during the scalp exposure and closure. CVG may also complicate the postoperative course if adequate approximation of the tissues cannot be achieved, resulting in wound infection and/or cerebrospinal fluid leak. The presented patient benefited from a combined neurosurgical and plastic surgical approach that was implemented intraoperatively and continued through the postoperative stages and the subsequent cranioplasty.