Comment on Balsamo et al.: "Birt-Hogg-Dubé syndrome with simultaneous hyperplastic polyposis of the gastrointestinal tract: case report and review of the literature".

In this comment, we highlight the diagnosis of Birt-Hogg-Dubé (BHD) in a 60-year-old man was made from identification and removal of normochromic papular cutaneous lesions whose histological examination indicated trichodyscomas and which are considered equivalent to fibrofolliculomas, presence of bilateral renal mass suggestive of angiomyolipomas by imaging exams. A benign/likely benign variant of FLCN in the intron 13 was also detected. Still, his previous pathological history presented other relevant data such as the prior removal of vocal cord angioma, total thyroidectomy, and left parotidectomy due to a cystic lesion whose histopathological examination revealed the presence of oncocytoma and lipomatosis, in addition to basal cell cutaneous carcinoma. Simultaneous gastrointestinal hyperplastic polyposis was found in this patient. The case we reported does not have the genotypic and phenotypic expressions most present in BHDS. These facts make it important for readers to know the clinical and genetic presentation facets of this unusual syndrome.

Birt-Hogg-Dubé syndrome with simultaneous hyperplastic polyposis of the gastrointestinal tract: case report and review of the literature.

BACKGROUND: Birt-Hogg-Dubé syndrome (BHDS) is a rare autosomal dominant genodermatosis characterized by benign growth of the hair follicles, the presence of pulmonary cysts, spontaneous pneumothorax, and bilateral renal tumors that are usually hybrid oncocytic or multifocal chromophobe renal cell carcinoma. The diagnosis is confirmed by the presence of a pathogenic variant in the tumor suppressor folliculin (FLCN) gene mapped at 17p11.2. Although the dermatological lesions typical of BHDS are benign and only cause aesthetic concerns, and the pulmonary manifestations are controllable, the greater tendency of patients with this syndrome to present benign or malignant renal tumors, often bilateral and multifocal, makes the diagnosis of this syndrome important for the prognosis of the patients. The objective was to report the case of a patient with BHDS, without pulmonary manifestations and with hyperplastic polyposis of the gastrointestinal tract, and to perform a literature review. CASE PRESENTATION: A 60-year-old man complained of abdominal pain and diarrhoea for 2 months. Physical examination was normal except for the presence of normochromic papules in the frontal region of the face associated with hyperkeratotic and hyperchromic papules in the dorsal region. The excisional biopsies of the skin lesions indicated trichodiscomas. Esophagogastroduodenoscopy, enteroscopy, and colonoscopy showed the presence of hyperplastic polyps in the stomach, duodenum, jejunum, colon, and rectum. Computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen revealed multiple expansive solid lesions in both kidneys, with necrotic and calcified areas. Renal magnetic resonance angiography also showed a solid lesion in the right kidney measuring 5 cm in diameter and another solid lesion in the left kidney measuring 8 cm in diameter, both suggestive of renal angiomyolipoma. CT scans of the skull, chest, and temporal bones were normal. The genetic study revealed the presence of a variant of FLCN in the intron 13. CONCLUSIONS: To the best of our knowledge, this is the first reported case of BHDS with the simultaneous finding of gastrointestinal hyperplastic polyposis, which may represent a possible phenotypic expression of this syndrome that has not yet been described.

von Hippel-Lindau Syndrome: Genetic Study of Case With a Rare Pathogenic Variant With Optic Nerve Hemangioblastoma, a Rare Phenotypic Expression.

von Hippel-Lindau syndrome (VHLS) is a rare, autosomal dominant genetic disease with high penetrance and variable phenotypic expression caused by variants in the VHL gene. VHLS is associated with the presence of vascular tumors, often hemangioblastoma of the central nervous system, retina, or spinal cord and, less frequently, pancreatic cystic neoplasm, pancreatic neuroendocrine tumor, clear cell carcinoma of the kidney, endolymphatic sac tumor, pheochromocytoma, and paraganglioma. The authors report a case of a patient with VHLS with a rare pathogenic variant in the VHL gene and with an optic nerve hemangioblastoma, a rare phenotypic expression. Case report: A 49-year-old woman was diagnosed with cystic neoplasm of the pancreas, renal cell carcinoma of the right kidney, and hemangioblastoma of the left optic nerve. The patient's family history revealed siblings with VHLS manifestations. The index case was her mother who died at age 63 of clear cell renal carcinoma. The information was obtained by consulting the patient's medical register and by interviews with the patient and her relatives. The presence of left optic nerve hemangioblastoma was suggested by CT scan of the skull and orbit. The sequencing of the VHL gene was performed in the peripheral blood by the polymerase chain reaction (PCR) technique, and the duplication and deletion research was performed using the multiplex ligation-dependent probe amplification (MPLA) technique. The presence of a rare pathogenic variant c.263G> A (p.Trp88Ter) was observed in heterozygosity in the VHL gene that determined a premature stop codon. CT scan of the skull and orbits suggested the presence of HB in the optic nerve of the left eye. The results of the CT scan of the skull and orbits show thickening with tortuosity of the left optic nerve, with a small area of nodular enhancement. The right optic nerve had a conserved aspect. Conclusion: This is the fourth case described of this rare pathogenic variant of the VHL gene, according to the Human Gene Mutation Database and VHLdb database records and with an optic nerve hemangioblastoma of the optic nerve, a very rare phenotypic expression of the VHLS.

Extensive colorectal lymphomatous polyposis complicated by acute intestinal obstruction: a case report.

BACKGROUND: Multiple lymphomatous polyposis is a rare type of gastrointestinal lymphoma that extensively infiltrates the intestine. Multiple lymphomatous polyposis originates from the mantle zone of the lymphoma follicle and is considered to be a mantle cell lymphoma, which is a relatively aggressive type of B-cell non-Hodgkin's lymphoma. We report an unusual case of a patient with multiple lymphomatous polyposis with extensive colorectal involvement and acute intestinal obstruction, an atypical complication of this rare disease. On the basis of this case study, the pitfalls in gastrointestinal tract lymphomatous polyposis diagnosis and prognosis, as well as the treatment options, are discussed. CASE PRESENTATION: Our patient was a 76-year-old white woman with asthenia, cramps, and swelling in the lower left quadrant of the abdomen, as well as weight loss within the previous 5 months. A colonoscopy revealed polyps in the rectum, sigmoid colon, descending colon, and right and left colic flexures. A biopsy revealed lymphomatous infiltration of the intestinal wall. Because of the large size of the polypoid masses, which narrowed the colonic lumen in multiple locations, the patient developed acute intestinal obstruction and was referred for laparotomy. She underwent a total proctocolectomy with a permanent ileostomy and a left salpingo-oophorectomy. Microscopic examination showed the presence of a multicentric, low-grade, small lymphocytic lymphoma. Immunohistochemical analysis revealed positive immunostaining for CD79a, CD20, and CD45. These results were consistent with the diagnosis of mantle cell lymphoma. Two weeks after surgery and prior to discharge, but before the beginning of chemotherapy, the patient's general condition worsened as she experienced a severe and progressive respiratory tract infection, advanced respiratory insufficiency, and septic shock, and she ultimately died. CONCLUSIONS: Mantle cell lymphoma develops as a progressive and aggressive disease with widespread polyposis of the gastrointestinal tract. The intensive chemotherapeutic regimens usually result in the regression of macroscopic and microscopic lesions; however, remissions are short in duration, and the median length of patient survival is 3-4 years. Mantle cell lymphoma is a rare disease that should be part of the differential diagnosis of polypoid diseases of the large intestine.