Hamartomas and choristomas in the nervous system

Sporadic Spinal Hamartoma in Adults: A Rare Pathologic Entity

BACKGROUND

Sporadic spinal hamartomas in adults are extremely rare tumor-like lesions, without defined guidelines of treatment. The aim of this study is to investigate the peculiar features of this pathologic entity to support a more accurate diagnosis and management.

METHODS

A comprehensive and detailed literature review of sporadic spinal hamartomas in adults, including a personal case, was performed. Demographic (sex and age), clinical (presenting symptoms), radiologic and pathologic (size, localization, dural and spinal cord relationship of lesion) features, as well as treatment (time to surgery, extent of resection, perioperative and postoperative complications) and outcome (clinical) data were analyzed.

RESULTS

Seven studies, including 7 patients, were eligible for the review. A personal case was also added. Sporadic adult spinal hamartomas equally affect males and females, in a range of age from 18 to 75 years; sensory radicular deficits were detected in all patients at clinical onset; thoracic segment (4/8) of the spine and intradural compartment (6/8) were most involved. All patients underwent surgery and just one experimented postoperative complication; gross total resection was achieved in only 3 patients, mainly in an extradural localization; clinical improvement at last follow-up was reported in all but 1 patient.

CONCLUSIONS

Spinal hamartomas in adults may sometimes account for progressive worsening of neurologic symptoms and lead to potentially irreversible neurologic deficit; therefore, prompt and adequate diagnosis and treatment are mandatory. Surgical resection represents the only curative treatment and is indicated for symptomatic lesions to achieve neurologic symptoms restoration or arrest/prevent their progressive deterioration.

Intraspinal choristoma in the lumbar region: A case report

RATIONALE

Intraspinal choristoma is a relatively uncommon intervertebral canal tumor. Prior to our reports, only 2 cases of intraspinal choristoma had been reported. Because this disease is not common and looks like a mass of fatty tissue on the magnetic resonance imaging (MRI), intraspinal choristoma can be easily misdiagnosed as teratomas or lipomas (like the case of this article presenting) without a pathology report. So if a lumber intraspinal lesion is discovered in a clinical examination, intraspinal choristoma should be considered as a differential diagnosis. We present a case of intraspinal choristoma that is unlike any other reported case.

PATIENT CONCERNS

A 35-year-old woman with left lower extremity hypoesthesia and burning-like pain in the lumbar region for 1 month visited the local hospital for plain lumbar spine MRI. The patient was diagnosed with a lumbar space-occupying lesion. A second plain lumbar spine MRI scan and a MRI scan with enhancement were performed in our hospital to confirm the presence of a congenital lipoma in the spinal canal. A postoperative biopsy of the lumbar spinal mass indicated that the mass was an intraspinal choristoma located in the spinal canal.

DIAGNOSIS

Intraspinal choristoma.

INTERVENTION

The lesion was surgically removed, and follow-up plain and enhanced MRI images of the patient's lumbar spine were obtained.

OUTCOMES

After surgery, the patient no longer experienced the burning pain in her lumbar region or the left lower extremity hypoesthesia when the patient was discharged. And there was no evidence of recurrence 2 years after the surgery.

LESSONS

The MRI presentation of intraspinal choristoma is similar to intraspinal lipoma. Therefore, a pathological assessment is critical to provide an accurate diagnosis.

Mammalian tumor-like organs. 1. The role of tumor-like normal organs and atypical tumor organs in the evolution of development (carcino-evo-devo)

Background

Earlier I hypothesized that hereditary tumors might participate in the evolution of multicellular organisms. I formulated the hypothesis of evolution by tumor neofunctionalization, which suggested that the evolutionary role of hereditary tumors might consist in supplying evolving multicellular organisms with extra cell masses for the expression of evolutionarily novel genes and the origin of new cell types, tissues, and organs. A new theory—the carcino-evo-devo theory—has been developed based on this hypothesis.

Main text

My lab has confirmed several non-trivial predictions of this theory. Another non-trivial prediction is that evolutionarily new organs if they originated from hereditary tumors or tumor-like structures, should recapitulate some tumor features in their development. This paper reviews the tumor-like features of evolutionarily novel organs. It turns out that evolutionarily new organs such as the eutherian placenta, mammary gland, prostate, the infantile human brain, and hoods of goldfishes indeed have many features of tumors. I suggested calling normal organs, which have many tumor features, the tumor-like organs.

Conclusion

Tumor-like organs might originate from hereditary atypical tumor organs and represent the part of carcino-evo-devo relationships, i.e., coevolution of normal and neoplastic development. During subsequent evolution, tumor-like organs may lose the features of tumors and the high incidence of cancer and become normal organs without (or with almost no) tumor features.

Muscular and collagenous cerebellar choristoma in a dog

This report aims to describe the first case of muscular and collagenous choristoma in a dog. A 10-yr-old female mixed-breed dog presented with lateral recumbence, vocalization, positional vertical nystagmus, divergent strabismus, anisocoria, and status epilepticus. The clinical condition evolved to stupor and ultimately, death. Necropsy revealed a white mass causing an irregular increase in the volume of the cerebellar vermis. In histological analysis, a well circumscribed, unencapsulated mass was observed in the cerebellum, consisting of fibers of striated skeletal muscle and collagen fibers, mostly mineralized. Based on the histopathological and histochemical findings, a diagnosis of muscular and collagenous cerebellar choristoma was made.

A novel mechanism for the formation and propagation of neural tumors and lesions through neural highways

By recognizing anatomic and radiologic patterns of rare and often misdiagnosed peripheral nerve tumors/lesions, we have defined mechanisms for the propagation of neural diseases. The novel concept of the nervous system serving as a complex system of "highways" driving the neural and perineural spread of these lesions is described in three examples: Intraneural dissection of joint fluid in intraneural ganglion cysts, perineural spread of cancer cells, and dissemination of unknown concentrations of neurotrophic/inhibitory factors for growth in hamartomas/choristomas of nerve. Further mapping of these pathways to identify the natural history of diseases, the spectrum of disease evolution, the role of genetic mutations, and how these neural pathways interface with the lymphatic, vascular, and cerebrospinal systems may lead to advances in targeted treatments.

[Trigeminal nerve lipoma presenting with trigeminal neuralgia: case report and literature review]

Cerebellopontine angle lipomas are benign mass lesions and rarely result trigeminal neuralgia. A 61-year-old male with right-sided trigeminal neuralgia in V2 and V3 divisions without sensory disturbances is reported in the article. MRI revealed mass lesion 11´11´4 mm on the lateral pontine surface spreading to the right trigeminal nerve root entry zone. No signs of neurovascular compression were found. Microsurgical exploration of the cerebellopontine angle showed a fatty mass adherent to the brainstem with incorporation of inferior part of trigeminal nerve root. Fatty tissue resection was followed by partial sensory trigeminal rhizotomy. Histological examination identified lipoma. Postoperative MRI showed small residual tissue with minimal ischemic area near trigeminal nerve root entry zone. Mild hypoesthesia within V2 and V3 trigeminal branches occurred after surgery. Trigeminal neuralgia completely resolved, and medications were discontinued. This clinical case and literature review clearly demonstrated successful elimination of trigeminal neuralgia in patients with cerebellopontine angle lipoma after resection of mass lesion and partial trigeminal rhizotomy.

Genetic Characterization of Myoid Hamartoma of the Breast

BACKGROUND/AIM

Myoid hamartoma of the breast is a very rare benign lesion of which only a few cases have been reported. The pathogenesis is unknown and nothing is known about its genetic constitution. We report here the genetic characterization of a myoid hamartoma of the breast.

MATERIALS AND METHODS

Cytogenetic, fluorescence in situ hybridization (FISH), RNA sequencing, reverse transcription polymerase chain reaction (RT-PCR), and Sanger sequencing analyses were performed on a myoid hamartoma of the breast.

RESULTS

G-Banding analysis of short-term cultured tumor cells yielded the karyotype 46,XX,t(5;12)(p13;q14)[6]/46,XX[4]. FISH showed rearrangement of the high mobility group AT-hook 2 (HMGA2) gene. RNA sequencing detected fusion of HMGA2 (12q14) with a sequence from 5p13. RT-PCR together with Sanger sequencing verified the HMGA2-fusion transcript.

CONCLUSION

Myoid hamartoma of the breast may be pathogenetically related to benign connective tissue tumors with HMGA2 rearrangements, such as pulmonary hamartomas, lipomas, myolipomas, and leiomyomas.