Cutaneous hyperpigmentation and familial gastrointestinal stromal tumour associated with KIT mutation

Abstract

Summary Gastrointestinal stromal tumours (GISTs) are mesenchymal tumours arising in the gastrointestinal tract. Early detection, before metastasis occurs, is important as complete surgical excision achieves cure. Approximately 85% of GISTs are associated with mutations in the KIT gene, and although the majority of GISTs are sporadic, familial GISTs have been identified. Several families with multiple GIST tumours have also been described with various cutaneous findings including hyperpigmentation, multiple lentigines, vitiligo and urticaria pigmentosa. We discuss a 6‐year‐old boy who presented with an unusual pattern of hyperpigmentation in association with a family history of GIST. A causative KIT mutation was identified in DNA from the pigmented skin and from the resected GIST, and the patient was referred to the Paediatric Gastroenterology department for GIST screening. The term ‘GIST cutaneous hyperpigmentation disease’ has been suggested previously for the association of familial GIST with cutaneous hyperpigmentation caused by a germline KIT mutation.

Novel KIT mutation presenting as marked lentiginosis

“…It is interesting to note the similarities between our patient and the 6‐year‐old boy with a KIT mutation described by Wali et al Both patients presented with an unusual pattern of progressive, confluent hyperpigmentation in similar locations (natal cleft, groin creases, and mons pubis). However, our patient also had multiple pronounced lentigines in addition to hyperpigmentation.…”

“…However, our patient also had multiple pronounced lentigines in addition to hyperpigmentation. The differing cutaneous presentation may be explained by the different KIT mutation identified by Wali et al (c.1733_1735delATG, p.(D579del). The variant in our patient (c.2485G>C; p.A829P) had not been reported in any databases of normal variation.…”

Cutaneous Hyperpigmentation and Familial Gastrointestinal Stromal Tumor Associated With Germline KIT Mutation Treated With Imatinib: A Chinese Case Report

“…With a wide range of clinical behaviors, prognosis of GISTs varies from indolent disorders with low risks to highly malignant diseases that may metastasize and become lethal 2 . It is known that mutations of the KIT gene have been identi ed in several human tumors, including multiple GISTs 3 . The KIT gene, a proto-oncogene, is of great signi cance in the development of various cell lines including the interstitial cells of Cajal and melanocytes 4 .…”

Generalized lentigines associated with familial gastrointestinal stromal tumors dramatically improved by imatinib treatment

“…So far, 35 different families of familial GIST have been reported. 2,3 However, the dermoscopic examination of the pigmented lesion has never been shown. In this case, the pigmented spots in the palm showed a parallel furrow pattern in contrast with the parallel ridge pattern of Peutz-Jeghers syndrome.…”

“…1,2 In diagnosing melanocytic lesion in lymph nodes, FISH is a useful adjunct tool. 3 None of the following four criteria for malignant melanoma were met (patient's…”