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A rare case of blue nevus in the rectum
Human Pathology: Case Reports 18 (2019) 200341
Contents lists available at ScienceDirect
Human Pathology: Case Reports journal homepage: www.elsevier.com/locate/ehpc
Case Report
A rare case of blue nevus in the rectum a
T
b
Shroque Zaher , Nada Sedeeq a b
Mohammed Bin Rashid University of Medicine and Health sciences, Dubai, United Arab Emirates Mediclinic Al Noor Hospital, Abu Dhabi, United Arab Emirates
ARTICLE INFO
ABSTRACT
Keywords: Rectum Blue nevus
A 54 year old female of Sudanese origin with a history of hypothyroidism and hyperlipidemia presented to the gastroenterology department complaining of chronic abdominal pain, nausea and heartburn. Colonoscopy revealed an incidental 5 mm pigmented lesion just above the dentate line, which, following microscopy, was diagnosed as a blue nevus. To date, there are only 3 cases reported in the literature of this rare entity. Our case represents the fourth such case.
1. Case report A 54-year-old female of Sudanese origin with a history of hypothyroidism and hyperlipidemia presented to the gastroenterology department complaining of chronic abdominal pain, nausea and heartburn. There was no change in appetite or bowel habit and she denied any weight loss, fever and rashes. There was no family history of inflammatory bowel disease or colon cancer. On examination, there were normal bowel sounds and a soft, non-tender, non-distended abdomen without hepatomegaly or splenomegaly. Rectal examination revealed no fissures or masses. Stool examination revealed yellow watery stool with no blood. Apart from anemia (Hb 10.4), her blood tests were unremarkable. The patient was scheduled for a gastroscopy and colonoscopy for further evaluation of her chronic abdominal pain. Gastroscopy showed pan gastritis and a colonoscopy revealed a 5 mm pigmented lesion of the rectum, just above the dentate line (See Fig. 1). No other lesions were seen. We received three fragments of tissue, all of which measured 0.2 × 0.1 cm. Microscopy revealed large bowel mucosa containing pigmented spindle cells within the lamina propria. There was no cellular atypia or mitoses. The cells stained strongly positive for HMB45, S-100 and Melan-A (see Figs. 2–4). 2. Discussion A blue naevus is a small, solitary blue- or grey-coloured lesion of the skin, with a similar appearance to a mole. It is believed to represent an abnormal arrest in embryonal migration of neural crest melanocytes [10]. They derive their blue colour from the relatively deep position of melanin pigment within the epidermis, where longer wave lengths are
absorbed and the shorter wave lengths are reflected, corresponding to the colour blue – known as the Tyndall effect. The common blue naevus is a bluish, smooth surfaced macule, papule or plaque ranging in size from 0.5 to 1 cm. They are generally round, or oval in shape and do not have any complications. They are benign and stay unchanged throughout life. A morphologic variant of blue nevus known as sclerosing (desmoplastic) blue nevus should be distinguished from desmoplastic melanoma. The most helpful features favouring desmoplastic melanoma include atypical junctional proliferation, cytologic atypia including nuclear enlargement and hyperchromasia, presence of reactive lymphoid infiltrate at the periphery of the lesion and mitotic activity (rare in desmoplastic melanoma but unheard of in sclerosing blue nevus). In rare cases, which cannot be resolved by routine examination, immunohistochemistry is helpful. S100 is usually the only melanocytic marker expressed by desmoplastic melanoma [9], while expression of HMB45 is exceptionally rare. In contrast, strong expression of HMB45 is an expected feature in all blue nevi [9]. Cellular blue nevi (which is a common variant) may also pose a diagnostic pitfall microscopically. They are larger in size, (at least 1 cm in diameter). Histologically, low power examination typically reveals a characteristic dumb bell architecture, which often gives a clue to the diagnosis. Higher-power examination reveals nests or fascicles of larger spindle-shaped or epithelioid cells with pale to clear cytoplasm containing variable pigment and large ovoid nuclei. The marked cellularity of a cellular blue nevus can be worrisome for melanoma. However, reassuring features include minimal cytological atypia, rare mitoses (none atypical) and the absence of tumour necrosis or epidermal ulceration. FISH analysis can also be an important diagnostic adjunct in melanocytic lesions. Blue nevus-like melanomas show significant chromosomal aberrations in 6p25 (RREB1), 6q23 (MYB), 11q13 (CCND1) and
E-mail address: [email protected] (S. Zaher). https://doi.org/10.1016/j.ehpc.2019.200341 Received 3 June 2019; Received in revised form 10 September 2019; Accepted 11 September 2019 2214-3300/ © 2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
Human Pathology: Case Reports 18 (2019) 200341
S. Zaher and N. Sedeeq
Fig. 4. ×10 magnification: strong staining of spindle melanocytes with S-100
Fig. 1. Pigmented lesion seen on colonoscopy of the rectum.
arranged in interlacing fascicles or nests. The tumours are characterized by accumulation of melanin in neoplastic cells and associated melanophages. Melanotic schwannomas associated with Carney complex may show sheets of adipose-like cells and psammoma bodies [7]. Blue nevi of mucosal surfaces is an infrequent occurrence with the most common location being the oral mucosa. Other sites described include, nasal mucosa, cervix, vagina and prostate [2,5,6]. Three other cases of rectal blue nevi, have been reported in the literature, all of which were discovered incidentally during routine colonoscopy [1,3,4]. 3. Conclusion Rectal blue nevi are benign lesions and no further follow up is usually required. Despite the rarity of these lesions in this location, we feel this is an important entity to consider in the differential diagnosis of pigmented mucosal lesions of the rectum. Informed consent
Fig. 2. ×10 magnification: rectal mucosa showing a proliferation of pigmented spindle cells within the lamina propria.
Written informed consent was obtained from the patient. Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References [1] N. Mohan, et al., Rectal blue nevus: distinguishing features of a rare entity, ACG Case Rep. J. 3 (4) (2016) e168. [2] W.-Y. Chuang, et al., Blue Nevi of the sinonasal mucosa: a report of two cases and review of the literature, Laryngoscope 117 (2) (2007) 371–372. [3] J. Makker, et al., Rectal blue nevus: case report of a rare entity and literature review, Pathol. Res. Pract. 211 (8) (2015) 625–627. [4] Z.J. Schreiber, T.R. Pal, S.J. Hwang, Blue nevus of the colorectal mucosa, Ann. Diagn. Pathol. 15 (2) (2011) 128–130. [5] A.H. Qizilbash, Blue nevus of the uterine cervix: report of a case, Am. J. Clin. Pathol. 59 (6) (1973) 803–806. [6] Virginia L. Dailey, Omar Hameed, Blue Nevus of the prostate, Arch. Pathol. Lab. Med. 135 (6) (2011) 799–802. [7] B.A. Alexiev, P.M. Chou, L.J. Jennings, Pathology of melanotic schwannoma, Arch. Pathol. Lab. Med. 142 (12) (2018) 1517–1523. [8] P. Pouryazdanparast, et al., Distinguishing epithelioid blue nevus from blue nevuslike cutaneous melanoma metastasis using fluorescence in situ hybridization, Am. J. Surg. Pathol. 33 (9) (2009) 1396–1400. [9] A. Zembowicz, P.A. Phadke, Blue nevi and variants: an update, Arch. Pathol. Lab. Med. 135 (3) (2011) 327–336. [10] P.A. Phadke, A. Zembowicz, Blue nevi and related tumors, Clin. Lab. Med. 31 (2) (2011) 345–358.
Fig. 3. ×10, magnification strong staining of spindle melanocytes with Melan-A.
centromere 6 (CEP 6) which are not seen in blue nevi [8]. Another potential differential diagnosis to consider for a pigmented spindle cell lesion is melanotic schwannoma which although not yet reported in this location, would have a similar immunohistochemical profile. Histology may show plump spindle and epithelioid cells 2
Contents lists available at ScienceDirect
Human Pathology: Case Reports journal homepage: www.elsevier.com/locate/ehpc
Case Report
A rare case of blue nevus in the rectum a
T
b
Shroque Zaher , Nada Sedeeq a b
Mohammed Bin Rashid University of Medicine and Health sciences, Dubai, United Arab Emirates Mediclinic Al Noor Hospital, Abu Dhabi, United Arab Emirates
ARTICLE INFO
ABSTRACT
Keywords: Rectum Blue nevus
A 54 year old female of Sudanese origin with a history of hypothyroidism and hyperlipidemia presented to the gastroenterology department complaining of chronic abdominal pain, nausea and heartburn. Colonoscopy revealed an incidental 5 mm pigmented lesion just above the dentate line, which, following microscopy, was diagnosed as a blue nevus. To date, there are only 3 cases reported in the literature of this rare entity. Our case represents the fourth such case.
1. Case report A 54-year-old female of Sudanese origin with a history of hypothyroidism and hyperlipidemia presented to the gastroenterology department complaining of chronic abdominal pain, nausea and heartburn. There was no change in appetite or bowel habit and she denied any weight loss, fever and rashes. There was no family history of inflammatory bowel disease or colon cancer. On examination, there were normal bowel sounds and a soft, non-tender, non-distended abdomen without hepatomegaly or splenomegaly. Rectal examination revealed no fissures or masses. Stool examination revealed yellow watery stool with no blood. Apart from anemia (Hb 10.4), her blood tests were unremarkable. The patient was scheduled for a gastroscopy and colonoscopy for further evaluation of her chronic abdominal pain. Gastroscopy showed pan gastritis and a colonoscopy revealed a 5 mm pigmented lesion of the rectum, just above the dentate line (See Fig. 1). No other lesions were seen. We received three fragments of tissue, all of which measured 0.2 × 0.1 cm. Microscopy revealed large bowel mucosa containing pigmented spindle cells within the lamina propria. There was no cellular atypia or mitoses. The cells stained strongly positive for HMB45, S-100 and Melan-A (see Figs. 2–4). 2. Discussion A blue naevus is a small, solitary blue- or grey-coloured lesion of the skin, with a similar appearance to a mole. It is believed to represent an abnormal arrest in embryonal migration of neural crest melanocytes [10]. They derive their blue colour from the relatively deep position of melanin pigment within the epidermis, where longer wave lengths are
absorbed and the shorter wave lengths are reflected, corresponding to the colour blue – known as the Tyndall effect. The common blue naevus is a bluish, smooth surfaced macule, papule or plaque ranging in size from 0.5 to 1 cm. They are generally round, or oval in shape and do not have any complications. They are benign and stay unchanged throughout life. A morphologic variant of blue nevus known as sclerosing (desmoplastic) blue nevus should be distinguished from desmoplastic melanoma. The most helpful features favouring desmoplastic melanoma include atypical junctional proliferation, cytologic atypia including nuclear enlargement and hyperchromasia, presence of reactive lymphoid infiltrate at the periphery of the lesion and mitotic activity (rare in desmoplastic melanoma but unheard of in sclerosing blue nevus). In rare cases, which cannot be resolved by routine examination, immunohistochemistry is helpful. S100 is usually the only melanocytic marker expressed by desmoplastic melanoma [9], while expression of HMB45 is exceptionally rare. In contrast, strong expression of HMB45 is an expected feature in all blue nevi [9]. Cellular blue nevi (which is a common variant) may also pose a diagnostic pitfall microscopically. They are larger in size, (at least 1 cm in diameter). Histologically, low power examination typically reveals a characteristic dumb bell architecture, which often gives a clue to the diagnosis. Higher-power examination reveals nests or fascicles of larger spindle-shaped or epithelioid cells with pale to clear cytoplasm containing variable pigment and large ovoid nuclei. The marked cellularity of a cellular blue nevus can be worrisome for melanoma. However, reassuring features include minimal cytological atypia, rare mitoses (none atypical) and the absence of tumour necrosis or epidermal ulceration. FISH analysis can also be an important diagnostic adjunct in melanocytic lesions. Blue nevus-like melanomas show significant chromosomal aberrations in 6p25 (RREB1), 6q23 (MYB), 11q13 (CCND1) and
E-mail address: [email protected] (S. Zaher). https://doi.org/10.1016/j.ehpc.2019.200341 Received 3 June 2019; Received in revised form 10 September 2019; Accepted 11 September 2019 2214-3300/ © 2019 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
Human Pathology: Case Reports 18 (2019) 200341
S. Zaher and N. Sedeeq
Fig. 4. ×10 magnification: strong staining of spindle melanocytes with S-100
Fig. 1. Pigmented lesion seen on colonoscopy of the rectum.
arranged in interlacing fascicles or nests. The tumours are characterized by accumulation of melanin in neoplastic cells and associated melanophages. Melanotic schwannomas associated with Carney complex may show sheets of adipose-like cells and psammoma bodies [7]. Blue nevi of mucosal surfaces is an infrequent occurrence with the most common location being the oral mucosa. Other sites described include, nasal mucosa, cervix, vagina and prostate [2,5,6]. Three other cases of rectal blue nevi, have been reported in the literature, all of which were discovered incidentally during routine colonoscopy [1,3,4]. 3. Conclusion Rectal blue nevi are benign lesions and no further follow up is usually required. Despite the rarity of these lesions in this location, we feel this is an important entity to consider in the differential diagnosis of pigmented mucosal lesions of the rectum. Informed consent
Fig. 2. ×10 magnification: rectal mucosa showing a proliferation of pigmented spindle cells within the lamina propria.
Written informed consent was obtained from the patient. Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References [1] N. Mohan, et al., Rectal blue nevus: distinguishing features of a rare entity, ACG Case Rep. J. 3 (4) (2016) e168. [2] W.-Y. Chuang, et al., Blue Nevi of the sinonasal mucosa: a report of two cases and review of the literature, Laryngoscope 117 (2) (2007) 371–372. [3] J. Makker, et al., Rectal blue nevus: case report of a rare entity and literature review, Pathol. Res. Pract. 211 (8) (2015) 625–627. [4] Z.J. Schreiber, T.R. Pal, S.J. Hwang, Blue nevus of the colorectal mucosa, Ann. Diagn. Pathol. 15 (2) (2011) 128–130. [5] A.H. Qizilbash, Blue nevus of the uterine cervix: report of a case, Am. J. Clin. Pathol. 59 (6) (1973) 803–806. [6] Virginia L. Dailey, Omar Hameed, Blue Nevus of the prostate, Arch. Pathol. Lab. Med. 135 (6) (2011) 799–802. [7] B.A. Alexiev, P.M. Chou, L.J. Jennings, Pathology of melanotic schwannoma, Arch. Pathol. Lab. Med. 142 (12) (2018) 1517–1523. [8] P. Pouryazdanparast, et al., Distinguishing epithelioid blue nevus from blue nevuslike cutaneous melanoma metastasis using fluorescence in situ hybridization, Am. J. Surg. Pathol. 33 (9) (2009) 1396–1400. [9] A. Zembowicz, P.A. Phadke, Blue nevi and variants: an update, Arch. Pathol. Lab. Med. 135 (3) (2011) 327–336. [10] P.A. Phadke, A. Zembowicz, Blue nevi and related tumors, Clin. Lab. Med. 31 (2) (2011) 345–358.
Fig. 3. ×10, magnification strong staining of spindle melanocytes with Melan-A.
centromere 6 (CEP 6) which are not seen in blue nevi [8]. Another potential differential diagnosis to consider for a pigmented spindle cell lesion is melanotic schwannoma which although not yet reported in this location, would have a similar immunohistochemical profile. Histology may show plump spindle and epithelioid cells 2