A 52-year-old man presented with a 4-month history of pink pruritic papules in the pubic area. He was undergoing treatment for stage IIIB colorectal adenocarcinoma, diagnosed 2 years earlier. On physical examination, he had skin phototype V and showed pink papules coalescing into an indurated, hyperpigmented plaque on his abdomen, scrotum, and right leg (Figs 1 and 2, A). He also had lymphedema of the legs, penis, and scrotum.
Fig 1.
Clinical photo. Grouped papules on the pubis forming a hardened, hyperpigmented plaque with a shell-like appearance. Some lesions are excoriated.
Fig 2.
Abdomen papules. (A) Clinical Photo. (B) Dermoscopy on polarized light. Globular structures with bright white septa forming a saccular pattern (blue arrows), surrounded by hyperpigmentation, dotted pigment with a pepeering-like (black arrows), with a fine network. White areas without structure (yellow arrow). Pale pink globular structures (green arrows). Punctate vessels (white arrow). Short, irregular linear vessels (red arrow).
Dermoscopy revealed globular structures with a saccular pattern, associated with bright white septa and brown borders, on a structureless white background with peppering-like pigmentation. The lesions were surrounded by pale pink globular areas, giving them an erythematous appearance. Scattered punctate vascular structures, short linear vessels, and irregular linear vessels were also identified (Figs 2 and 3, A, B).
Fig 3.
Cutaneous metastases from colorectal carcinoma. (A) Dermoscopy on polarized light. Close-up of globular structures with peppering-like punctate pigment. (B) Dermoscopy on polarized light. Areas with punctate vascular structures. (C) Malignant tumor infiltrating the dermis, proliferation of atypical glands, cells with irregular cytoplasm, pleomorphism, prominent nuclei, and atypical mitotic figures. Areas of central necrosis and desmoplastic stroma. (D) Accumulation of mucinous cells in the papillary dermis, (green arrow), generating a circular neoformation with central necrosis. (C and D, H&E stain; original magnifications: C, ×10; D, ×40).
Histopathological examination showed lymphatic invasion and infiltration of malignant glandular epithelial cells in the desmoplastic dermis, with morphology similar to the primary colorectal tumor (Fig 3), confirming the diagnosis of cutaneous metastasis.
Cutaneous metastases from colorectal carcinomas (CMCCs) are rare.1 Dermatoscopic reports of CMCC in light-skinned patients describe the main dermatoscopic findings as a polymorphic vascular pattern and a white, pinkish, or reddish background without defined structures.2, 3, 4, 5, 6 Since vascular patterns are more difficult to observe in dermoscopy of high-phototype patients, the description of new structures in these individuals could lead to earlier diagnoses and improved prognosis.2 Our patient presented saccular structures with bright white septa and peppering-like pigmentation, adding new CMCC findings. This case highlighted the need for further dermatoscopic documentation in patients with skin of color. The correlation of dermatoscopy structures is described in Table I.2,7,8
Table I.
Correlation of dermoscopy structures and histopathological findings of colorectal metastasis
| Dermoscopy findings | Histopathological correlation | Reference |
|---|---|---|
| Bright white partitions that form saccular structures | Thickened collagen bundles/desmoplastic stroma, associated with tumor infiltration in the dermis | Marghoob et al7 (2009) Massone et al8 (2021) |
| Structureless white area on a pink to red background | New collagen remodeling in the dermis | Chernoff, et al2 (2014) Marghoob et al7 (2009) |
| Vascular structures | Disorganized neo-angiogenesis | Chernoff et al2 (2014) |
| ∗Saccular structures with peppering-like pigment | Melanophages or melanin deposition adjacent to tumor nests | Authors’ theory, based on assone et al8 (2021) |
Patients with dark-skin.
Conflicts of interest
None disclosed.
Footnotes
Funding sources: None.
IRB approval status: Not applicable.
Patient consent: The authors attest that they have obtained written consent from patient/s, their legal guardian/s or person/s with legal authority, for their photographs and medical information to be published in print and online and with the understanding that this information may be publicly available. Patient consent forms were not provided to the journal but are retained by the authors to be made available upon request.
References
- 1.Udkoff J., Cohen P.R. Adenocarcinoma of the colon presenting with scrotal metastasis: case report and review of the literature. Dermatol Online J. 2016;22 13030/qt1jg0t4kw. [PubMed] [Google Scholar]
- 2.Chernoff K.A., Marghoob A.A., Lacouture M.E., Deng L., Busam K.J., Myskowski P.L. Dermoscopic findings in cutaneous metastases. JAMA Dermatol. 2014;150:429–433. doi: 10.1001/jamadermatol.2013.8502. [DOI] [PubMed] [Google Scholar]
- 3.AlSubait N.A., BinJadeed H.F., AlSaleh M.R., AlFaifi F.S., AlSaif F.M., Arafah M.A. Dermoscopy of scalp cutaneous metastasis of sigmoid adenocarcinoma. JAAD Case Rep. 2021;14:116–119. doi: 10.1016/j.jdcr.2021.06.004. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Manganoni A.M., Fusano M., Pavoni L., et al. A solitary cutaneous metastasis from colon adenocarcinoma: dermoscopic and confocal microscopy features. Indian J Dermatol Venereol Leprol. 2018;84:589. doi: 10.4103/ijdvl.IJDVL_304_17. [DOI] [PubMed] [Google Scholar]
- 5.Ito T., Yoshida Y., Yamada N., Furue M., Yamamoto O. Dermoscopy of peristomal polyps and metastasis of colon cancer. Acta Derm Venereol. 2014;94:96–97. doi: 10.2340/00015555-1646. [DOI] [PubMed] [Google Scholar]
- 6.Kamińska-Winciorek G., Wydmański J., Januszewski K., Silny W. Dermoscopy of nodular skin metastases from gastrointestinal primary cancer. Postepy Dermatol Alergol. 2015;32:312–316. doi: 10.5114/pdia.2015.48043. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Marghoob A.A., Cowell L., Kopf A.W., Scope A. Observation of chrysalis structures with polarized dermoscopy. Arch Dermatol. 2009;145:618. doi: 10.1001/archdermatol.2009.28. [DOI] [PubMed] [Google Scholar]
- 8.Massone C., Hofman-Wellenhof R., Chiodi S., Sola S. Dermoscopic criteria, histopathological correlates and genetic findings of thin melanoma on non-volar skin. Genes (Basel) 2021;12:1288. doi: 10.3390/genes12081288. [DOI] [PMC free article] [PubMed] [Google Scholar]