Adding left and top border to a section heading

Question

I would like to have a top and a side border around my section heading like this

I'm using titlesec \titleformat to define my sections.

So far I've been able to add a top rule by putting a \titlerule in the font definition but the side border is difficult. I suspect I should use some kind of more graphical package to set my borders but I don't know how to incorporate these into a \titleformat.

\titleformat{\subsubsection} % Customize the \subsection{} section title
{\color{cyan}\titlerule
    \vspace{.2ex}%
\sffamily\footnotesize\bfseries\color{cyan}} % Title font customizations
{\thesubsubsection} % Subsection number
{12pt} % Whitespace between the number and title
{\footnotesize} % Title font size
\titlespacing*{\subsubsection}{0mm}{3mm}{0mm} % Left, top and bottom spacing around the title

Answer 1

Relating to my comment, maybe this as a starting point:

\documentclass[12pt]{article}

\usepackage{lipsum}

\usepackage{titlesec,tikz}
\newcommand\titlebar{%
 \tikz[overlay]{ \draw [cyan,line width=.2ex] (-1.5ex,-1.5ex) -- (-1.5ex,3ex) -- (\textwidth,3ex); }%
}

\titleformat{\subsubsection}{\sffamily\bfseries\large\color{cyan}}{\titlebar\thesubsubsection}{12pt}{}

\begin{document}

\subsubsection{Another Subsubsection}

\lipsum[1]

\end{document} 

This yields: